diff --git a/README.md b/README.md
index 21ff6c6..d4ab040 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# SevenZip 📦
+# SevenZip 🔧
 
 A PHP package to compress and decompress files using 7zip CLI.
 
@@ -14,6 +14,8 @@ composer require verseles/sevenzip
 
 ## Usage
 
+### Compression
+
 To compress a file or directory:
 
 ```php
@@ -28,6 +30,26 @@ $sourcePath = '/path/to/source/file/or/directory';
 $sevenZip->compress($format, $archivePath, $sourcePath);
 ```
 
+You can also use the fluent interface:
+
+```php
+$sevenZip = new SevenZip();
+$sevenZip->format('7z')
+         ->source('/path/to/source/file/or/directory')
+         ->target('/path/to/archive.7z')
+         ->compress();
+```
+
+#### Compression Options
+
+- **Format**: You can set the compression format using the `format()` method. Supported formats include `7z`, `zip`, `tar`, `lz4`, `lz5`, `bzip2`,
+  and `zstd`.
+- **Compression Level**: You can adjust the compression level using the `faster()`, `slower()`, `mx()`, and `ultra()` methods.
+- **Custom Flags**: You can add custom compression flags using the `addFlag()` method.
+- **Progress Callback**: You can set a progress callback using the `progress()` method to monitor the compression progress.
+
+### Extraction
+
 To extract an archive:
 
 ```php
@@ -42,9 +64,18 @@ $extractPath = '/path/to/extract/directory';
 $sevenZip->extract($format, $archivePath, $extractPath);
 ```
 
+You can also use the fluent interface:
+
+```php
+$sevenZip = new SevenZip();
+$sevenZip->source('/path/to/archive.7z')
+         ->target('/path/to/extract/directory')
+         ->extract();
+```
+
 ## Supported Formats
 
-The package supports any format, but are aliased to the following:
+The package supports any format, but the following formats are aliased:
 
 - 7z (default to lzma2)
 - zip
@@ -55,14 +86,13 @@ The package supports any format, but are aliased to the following:
 - zstd
 
 > [!WARNING]
-> The format support are bound to your system, arch, etc.
-> If the wanted format are not in this list, please use addCustomCompressFlag() method.
+> The format support depends on your system, architecture, etc.
+> If the desired format is not in the list, please use the `addCompressFlag()` method.
 
 ## TODO / WIP
 
 - [ ] Add custom support for gz, xz, etc. by using tar flags
 - [ ] Use tar to keep original file permissions and other attributes
-- [ ] Add extract custom flags
 
 ## Contributing
 
@@ -84,6 +114,322 @@ To run the tests, execute the following command:
 make
 ```
 
+# Documentation / API
+
+## `__construct(?string $sevenZipPath = null)`
+
+Constructs a new SevenZip instance. If `$sevenZipPath` is not provided, it will attempt to automatically detect the 7-Zip executable. If the
+executable is not found, an `ExecutableNotFoundException` will be thrown.
+
+**Parameters**
+
+- `$sevenZipPath` (optional): Path to the 7-Zip executable file.
+
+**Throws**
+
+- `ExecutableNotFoundException`: If the 7-Zip executable is not found.
+
+## `getSevenZipPath(): ?string`
+
+Gets the path to the 7-Zip executable file.
+
+**Returns**: Path to the 7-Zip executable file.
+
+## `setSevenZipPath(string $sevenZipPath): SevenZip`
+
+Sets the path to the 7-Zip executable file.
+
+**Parameters**
+
+- `$sevenZipPath`: Path to the 7-Zip executable file.
+
+**Returns**: The current instance of the SevenZip class.
+
+## `source(string $path): static`
+
+Sets the source path for the compression or extraction operation.
+
+**Parameters**
+
+- `$path`: The source path.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->source('/path/to/source/file/or/directory');
+```
+
+## `format(string $format): static`
+
+Sets the archive format.
+
+**Parameters**
+
+- `$format`: The compression format to be used.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->format('7z');
+```
+
+## `compress(?string $format = null, ?string $sourcePath = null, ?string $targetPath = null): bool`
+
+Compresses a file or directory.
+
+**Parameters**
+
+- `$format` (optional): Archive format.
+- `$sourcePath` (optional): Path to the file or directory to compress.
+- `$targetPath` (optional): Path to the compressed archive.
+
+**Returns**: `true` on success.
+
+**Throws**
+
+- `InvalidArgumentException`: If format, target path, or source path is not set.
+
+**Example**
+
+```php
+$sevenZip->compress('7z', '/path/to/source', '/path/to/archive.7z');
+```
+
+## `getTargetPath(): string`
+
+Gets the target path for compression/extraction.
+
+**Returns**: The path to the target file or directory for compression or extraction.
+
+## `setTargetPath(string $path): static`
+
+Sets the target path for compression/extraction.
+
+**Parameters**
+
+- `$path`: The path to the target file or directory for compression or extraction.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->setTargetPath('/path/to/archive.7z');
+```
+
+## `getSourcePath(): string`
+
+Gets the source path for compression/extraction.
+
+**Returns**: The path to the source file or directory for compression or extraction.
+
+## `setSourcePath(string $path): static`
+
+Sets the source path for compression/extraction.
+
+**Parameters**
+
+- `$path`: The path to the source file or directory for compression or extraction.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->setSourcePath('/path/to/source/file/or/directory');
+```
+
+## `flagrize(array $flagsAndValues): array`
+
+Formats flags and values into an array of strings suitable for passing to 7-Zip commands.
+
+**Parameters**
+
+- `$flagsAndValues`: An associative array of flags and their corresponding values. If the value is null, the flag will be added without an equal sign.
+
+**Returns**: An array of formatted flag strings.
+
+**Example**
+
+```php
+$formattedFlags = $sevenZip->flagrize(['m0' => 'lzma2', 'mx' => 9]);
+// Output: ['-m0=lzma2', '-mx=9']
+```
+
+## `getFormat(): string`
+
+Gets the archive format.
+
+**Returns**: The compression format to be used.
+
+## `setFormat(string $format): static`
+
+Sets the archive format.
+
+**Parameters**
+
+- `$format`: The compression format to be used.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->setFormat('zip');
+```
+
+## `getCustomFlags(): array`
+
+Gets the custom compression flags.
+
+**Returns**: The custom compression flags that have been added.
+
+## `setCustomFlags(array $customFlags): SevenZip`
+
+Sets the custom compression flags.
+
+**Parameters**
+
+- `$customFlags`: The custom compression flags to be used.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->setCustomFlags(['mx' => 9, 'mfb' => 64]);
+```
+
+## `progress(callable $callback): static`
+
+Sets the progress callback using a fluent interface.
+
+**Parameters**
+
+- `$callback`: The callback function to be called during the compression progress.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->progress(function ($progress) {
+    echo "Progress: {$progress}%\n";
+});
+```
+
+## `faster(): static`
+
+Sets the compression level to faster.
+
+**Returns**: The current instance of the SevenZip class.
+
+## `mx(int $level): static`
+
+Sets the compression level using the `-mx` flag.
+
+**Parameters**
+
+- `$level`: The compression level to be used.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->mx(9); // Maximum compression
+```
+
+## `addFlag(string $flag, $value = null): static`
+
+Adds a compression flag.
+
+**Parameters**
+
+- `$flag`: The compression flag to be added.
+- `$value` (optional): The value for the flag.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->addFlag('mfb', 64);
+```
+
+## `slower(): static`
+
+Sets the compression level to slower.
+
+**Returns**: The current instance of the SevenZip class.
+
+## `ultra(): static`
+
+Configures maximum compression settings based on the specified format.
+
+**Returns**: The current instance of the SevenZip class.
+
+## `mmt(int|bool|string $threads = 'on'): static`
+
+Sets the number of CPU threads to use for compression.
+
+**Parameters**
+
+- `$threads`: The number of CPU threads to use, or 'on' or 'off'.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->mmt('on'); // Use all available CPU threads
+$sevenZip->mmt(4); // Use 4 CPU threads
+```
+
+## `mmem(int|string $size = 24): static`
+
+Sets the memory limit for compression.
+
+**Parameters**
+
+- `$size`: The memory limit in megabytes or as a string (e.g., '32m').
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->mmem(32); // Set memory limit to 32 MB
+```
+
+## `mpass(int $number = 7): static`
+
+Sets the number of passes for compression.
+
+**Parameters**
+
+- `$number`: The number of passes for compression.
+
+**Returns**: The current instance of the SevenZip class.
+
+**Example**
+
+```php
+$sevenZip->mpass(15); // Use 15 compression passes
+```
+
+## `reset(): SevenZip`
+
+Resets the property values to their original state.
+
+**Returns**: The current instance of the SevenZip class.
+
+This method resets the `customFlags`, `progressCallback`, `lastProgress`, `format`, `targetPath`, and `sourcePath` properties to their default values.
+
 ## License
 
 This package is open-sourced software licensed under the [MIT license](./LICENSE.md).
diff --git a/composer.json b/composer.json
index f9f0b7b..7bcd223 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
     }
   },
   "scripts": {
-    "test": "vendor/bin/phpunit tests/SevenZipTest.php --testdox"
+    "test": "vendor/bin/phpunit tests/SevenZipTest.php --testdox --display-warnings --color=always"
   },
   "config": {
     "sort-packages": true
diff --git a/src/Exceptions/ExecutableNotFoundException.php b/src/Exceptions/ExecutableNotFoundException.php
new file mode 100644
index 0000000..f6c28a9
--- /dev/null
+++ b/src/Exceptions/ExecutableNotFoundException.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Verseles\SevenZip\Exceptions;
+
+use Throwable;
+
+class ExecutableNotFoundException extends \Exception
+{
+
+  public function __construct($message = 'Executable 7z not found.', $code = 0, Throwable $previous = null)
+  {
+    parent::__construct($message, $code, $previous);
+  }
+
+}
diff --git a/src/SevenZip.php b/src/SevenZip.php
index 84be893..f754902 100644
--- a/src/SevenZip.php
+++ b/src/SevenZip.php
@@ -4,91 +4,355 @@
 
 use Symfony\Component\Process\ExecutableFinder;
 use Symfony\Component\Process\Process;
+use Verseles\SevenZip\Exceptions\ExecutableNotFoundException;
 
 class SevenZip
 {
-  private string $sevenZipPath;
-
-  private array $alwaysFlags          = ['-bsp1', '-y'];
-  private array $defaultCompressFlags = [
-    'zip'   => ['-tzip'],
-    '7z'    => ['-t7z'],
-    'lzma2' => ['-t7z'],
-    'lz4'   => ['-t7z', '-m0=lz4'],
-    'lz5'   => ['-t7z', '-m0=lz5'],
-    'bz2'   => ['-t7z', '-m0=bzip2'],
-    'bzip2' => ['-t7z', '-m0=bzip2'],
-    'zstd'  => ['-t7z', '-m0=zstd'],
-    'zst'   => ['-t7z', '-m0=zstd'],
-    'tar'   => ['-ttar'], // will make file bigger than source
-
-    // @TODO add custom support for gz, xz, etc by using tar flags
-    // @TODO use tar to keep original file permissions and others attributes
-    // @TODO add extract custom flags
+  /**
+   * Path to the 7-Zip executable file. If not set, it will be automatically detected.
+   * @var ?string
+   */
+  protected ?string $sevenZipPath = null;
+
+  /**
+   * Array of flags that are always used when running 7-Zip commands.
+   * These flags are used to suppress progress output and automatically confirm operations.
+   * @var array
+   */
+  protected array $alwaysFlags = ['bsp1', 'y' => null];
+
+  /**
+   * Default compression flags for different formats.
+   * Each format has a set of specific flags that are used to optimize the compression for that format.
+   * @var array
+   */
+  protected array $defaultCompressFlags = [
+    'zip'   => ['tzip'],
+    '7z'    => ['t7z', 'm0' => 'lzma2'],
+    'lzma2' => ['t7z', 'm0' => 'lzma2'],
+    'lz4'   => ['t7z', 'm0' => 'lz4'],
+    'lz5'   => ['t7z', 'm0' => 'lz5'],
+    'bz2'   => ['t7z', 'm0' => 'bzip2'],
+    'bzip2' => ['t7z', 'm0' => 'bzip2'],
+    'zstd'  => ['t7z', 'm0' => 'zstd'],
+    'zst'   => ['t7z', 'm0' => 'zstd'],
+    'tar'   => ['ttar'],
   ];
-  private       $customCompressFlags  = [];
-  private       $progressCallback;
 
   /**
+   * Custom flags that can be added to the 7-Zip command.
+   * These flags allow for further customization of the compression/extraction process.
+   * @var array
+   */
+  protected array $customFlags = [];
+
+  /**
+   * Callback function to be called during the compression progress.
+   * This function will be called with the current progress percentage as an argument.
+   * @var ?callable
+   */
+  protected $progressCallback;
+
+  /**
+   * The last reported progress percentage.
+   * @var int
+   */
+  protected int $lastProgress = -1;
+
+  /**
+   * The compression format to be used.
+   * @var ?string
+   */
+  protected ?string $format;
+
+  /**
+   * The path to the target file or directory for compression or extraction.
+   * @var string
+   */
+  protected string $targetPath;
+
+  /**
+   * The path to the source file or directory for compression or extraction.
+   * @var string
+   */
+  protected string $sourcePath;
+
+  /**
+   * Constructs a new SevenZip instance.
+   * If $sevenZipPath is not provided, it will attempt to automatically detect the 7-Zip executable.
+   * If the executable is not found, an ExecutableNotFoundException will be thrown.
    *
-   * @param string|null $sevenZipPath Path to 7z executable (optional).
-   * @throws \RuntimeException If 7z executable is not found.
+   * @param ?string $sevenZipPath Path to the 7-Zip executable file.
+   * @throws ExecutableNotFoundException If the 7-Zip executable is not found.
    */
-  public function __construct(string $sevenZipPath = null)
+  public function __construct(?string $sevenZipPath = null)
   {
-    if ($sevenZipPath === null) {
+    if ($sevenZipPath !== null) {
+      $this->setSevenZipPath($sevenZipPath);
+    }
+
+    if ($this->getSevenZipPath() === null) {
       $finder       = new ExecutableFinder();
       $sevenZipPath = $finder->find('7z');
+      $this->setSevenZipPath($sevenZipPath);
     }
 
-    if ($sevenZipPath === null) {
-      throw new \RuntimeException('Executable 7z not found.');
+    if ($this->getSevenZipPath() === null) {
+      throw new ExecutableNotFoundException();
     }
+  }
 
+  /**
+   * Gets the path to the 7-Zip executable file.
+   *
+   * @return ?string Path to the 7-Zip executable file.
+   */
+  public function getSevenZipPath(): ?string
+  {
+    return $this->sevenZipPath;
+  }
+
+  /**
+   * Sets the path to the 7-Zip executable file.
+   *
+   * @param string $sevenZipPath Path to the 7-Zip executable file.
+   * @return SevenZip The current instance of the SevenZip class.
+   */
+  public function setSevenZipPath(string $sevenZipPath): SevenZip
+  {
     $this->sevenZipPath = $sevenZipPath;
+    return $this;
+  }
+
+  /**
+   * Sets the source path for the compression or extraction operation.
+   *
+   * @param string $path The source path.
+   * @return static The current instance of the SevenZip class.
+   */
+  public function source(string $path): static
+  {
+    return $this->setSourcePath($path);
   }
 
   /**
-   * Compress a file or directory
+   * Set the archive format.
    *
-   * @param string $format Format of the archive
-   * @param string $archivePath Path to the file or directory to compress
-   * @param string $sourcePath Path to the compressed archive
+   * @param string $format The compression format to be used.
+   * @return $this The current instance of the SevenZip class.
    */
-  public function compress(string $format, string $archivePath, string $sourcePath): void
+  public function format(string $format): static
   {
+    return $this->setFormat($format);
+  }
+
+  /**
+   * Compress a file or directory.
+   *
+   * @param ?string $format Archive format (optional).
+   * @param ?string $sourcePath Path to the file or directory to compress (optional).
+   * @param ?string $targetPath Path to the compressed archive (optional).
+   * @return bool True on success.
+   * @throws \InvalidArgumentException If format, target path, or source path is not set.
+   *
+   */
+  public function compress(?string $format = null, ?string $sourcePath = null, ?string $targetPath = null): bool
+  {
+    if ($format !== null) {
+      $this->setFormat($format);
+    }
+
+    if ($sourcePath !== null) {
+      $this->setSourcePath($sourcePath);
+    }
+
+    if ($targetPath !== null) {
+      $this->setTargetPath($targetPath);
+    }
+
+    if (!$this->getTargetPath()) {
+      throw new \InvalidArgumentException('Archive file path (target) must be set or passed as argument');
+    }
+
+    if (!$this->getSourcePath()) {
+      throw new \InvalidArgumentException('File or directory path (source) must be set or passed as argument');
+    }
+
     $command = [
       $this->sevenZipPath,
       'a',
-      ...$this->alwaysFlags,
-      ...$this->getDefaultCompressFlags($format),
-      ...$this->customCompressFlags,
-      $archivePath,
-      $sourcePath,
+      ...$this->flagrize($this->getAlwaysFlags()),
+      ...$this->flagrize($this->getDefaultCompressFlags()),
+      ...$this->flagrize($this->getCustomFlags()),
+      $this->getTargetPath(),
+      $this->getSourcePath(),
     ];
 
+    return $this->runCommand($command);
+  }
 
-    $this->runCommand($command);
+  /**
+   * Get the target path for compression/extraction.
+   *
+   * @return string The path to the target file or directory for compression or extraction.
+   */
+  public function getTargetPath(): string
+  {
+    return $this->targetPath;
   }
 
   /**
-   * Get default flags for a given format.
+   * Set the target path for compression/extraction.
    *
-   * @param string $format Format of the archive
-   * @return array Default flags
+   * @param string $path The path to the target file or directory for compression or extraction.
+   * @return $this The current instance of the SevenZip class.
    */
-  private function getDefaultCompressFlags(string $format): array
+  public function setTargetPath(string $path): static
   {
-    return $this->defaultCompressFlags[$format] ?? [];
+    $this->targetPath = $path;
+    return $this;
   }
 
   /**
-   * Run a command and parse its output.
+   * Get the source path for compression/extraction.
    *
-   * @param array $command Command to run
-   * @throws \RuntimeException If the command fails
+   * @return string The path to the source file or directory for compression or extraction.
    */
-  private function runCommand(array $command): void
+  public function getSourcePath(): string
+  {
+    return $this->sourcePath;
+  }
+
+  /**
+   * Set the source path for compression/extraction.
+   *
+   * @param string $path The path to the source file or directory for compression or extraction.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function setSourcePath(string $path): static
+  {
+    $this->sourcePath = $path;
+    return $this;
+  }
+
+  /**
+   * Format flags and values into an array of strings suitable for passing to 7-Zip commands.
+   *
+   * @param array $flagsAndValues An associative array of flags and their corresponding values.
+   *                              If the value is null, the flag will be added without an equal sign.
+   * @return array An array of formatted flag strings.
+   */
+  public function flagrize(array $flagsAndValues): array
+  {
+    $formattedFlags = [];
+
+    foreach ($flagsAndValues as $flag => $value) {
+      if (is_numeric($flag)) {
+        $flag  = $value;
+        $value = null;
+      }
+
+      $formattedFlag = '-' . $flag;
+
+      if ($value !== null) {
+        $formattedFlag .= '=' . $value;
+      }
+
+      $formattedFlags[] = $formattedFlag;
+    }
+
+    return $formattedFlags;
+  }
+
+  /**
+   * Get the always flags.
+   *
+   * @return array The array of flags that are always used when running 7-Zip commands.
+   */
+  protected function getAlwaysFlags(): array
+  {
+    return $this->alwaysFlags;
+  }
+
+  /**
+   * Set the always flags.
+   *
+   * @param array $alwaysFlags The array of flags that are always used when running 7-Zip commands.
+   * @return SevenZip The current instance of the SevenZip class.
+   */
+  protected function setAlwaysFlags(array $alwaysFlags): SevenZip
+  {
+    $this->alwaysFlags = $alwaysFlags;
+    return $this;
+  }
+
+  /**
+   * Get the default compression flags for the specified format.
+   *
+   * @param string|null $format Archive format (optional).
+   * @return array The default compression flags for the specified format.
+   */
+  protected function getDefaultCompressFlags(?string $format = null): array
+  {
+    if ($format !== null) {
+      $this->setFormat($format);
+    }
+
+    return $this->defaultCompressFlags[$this->getFormat()] ?? ['t' . $this->getFormat()];
+  }
+
+  /**
+   * Get the archive format.
+   *
+   * @return string The compression format to be used.
+   */
+  public function getFormat(): string
+  {
+    return $this->format ?? '7z';
+  }
+
+  /**
+   * Set the archive format.
+   *
+   * @param string $format The compression format to be used.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function setFormat(string $format): static
+  {
+    $this->format = $format;
+    return $this;
+  }
+
+  /**
+   * Get the custom compression flags.
+   *
+   * @return array The custom compression flags that have been added.
+   */
+  public function getCustomFlags(): array
+  {
+    return $this->customFlags;
+  }
+
+  /**
+   * Set the custom compression flags.
+   *
+   * @param array $customFlags The custom compression flags to be used.
+   * @return SevenZip The current instance of the SevenZip class.
+   */
+  public function setCustomFlags(array $customFlags): SevenZip
+  {
+    $this->customFlags = $customFlags;
+    return $this;
+  }
+
+  /**
+   * Run a 7z command and parse its output.
+   *
+   * @param array $command The 7-Zip command to be executed.
+   * @return bool True if the command was successful
+   * @throws \RuntimeException If the command fails to execute successfully.
+   */
+  protected function runCommand(array $command): bool
   {
     $process = new Process($command);
     $process->run(function ($type, $buffer) {
@@ -100,86 +364,353 @@ private function runCommand(array $command): void
     if (!$process->isSuccessful()) {
       throw new \RuntimeException($process->getErrorOutput());
     }
+
+    $this->setProgress(100);
+
+    $this->reset();
+
+    return true;
   }
 
   /**
-   * Parses the progress from the command output and calls the progress callback.
+   * Parse the progress from the command output.
    *
-   * @param string $output Output of the command
+   * @param string $output The output from the 7-Zip command.
    */
-  private function parseProgress(string $output): static
+  protected function parseProgress(string $output): void
   {
-    if ($this->progressCallback === null) {
-      return $this;
+    if ($this->getProgressCallback() === null) {
+      return;
     }
 
     $lines = explode("\n", $output);
     foreach ($lines as $line) {
-      if (preg_match('/(\d+)%/', $line, $matches)) {
+      if (preg_match('/(\d+)%\s+\d+/', $line, $matches)) {
         $progress = intval($matches[1]);
-        call_user_func($this->progressCallback, $progress);
+        $this->setProgress($progress);
       }
     }
+  }
 
+  /**
+   * Get the progress callback.
+   *
+   * @return callable|null The callback function to be called during the compression progress.
+   */
+  public function getProgressCallback(): ?callable
+  {
+    return $this->progressCallback;
+  }
+
+  /**
+   * Set the progress callback.
+   *
+   * @param callable $callback The callback function to be called during the compression progress.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function setProgressCallback(callable $callback): static
+  {
+    $this->progressCallback = $callback;
     return $this;
   }
 
+  protected function setProgress(int $progress): void
+  {
+    if ($this->getProgressCallback() !== null && $progress > $this->getLastProgress()) {
+      $this->setLastProgress($progress);
+      call_user_func($this->getProgressCallback(), $progress);
+    }
+  }
+
   /**
-   * Decompress an archive
+   * Get the last reported progress.
    *
-   * @param string $format Format of the archive to extract
-   * @param string $archivePath Path to the archive
-   * @param string $extractPath Path to extract the archive
+   * @return int The last reported progress percentage.
    */
-  public function extract(string $format, string $archivePath, string $extractPath): void
+  public function getLastProgress(): int
   {
-    $command = [
-      $this->sevenZipPath,
-      'x',
-      ...$this->alwaysFlags,
-      $archivePath,
-      '-o' . $extractPath,
-    ];
+    return $this->lastProgress;
+  }
 
-    $this->runCommand($command);
+  /**
+   * Set the last reported progress.
+   *
+   * @param int $lastProgress The last reported progress percentage.
+   * @return SevenZip The current instance of the SevenZip class.
+   */
+  protected function setLastProgress(int $lastProgress): SevenZip
+  {
+    $this->lastProgress = $lastProgress;
+    return $this;
   }
 
   /**
-   * Adds a flag to the list of flags.
+   * Reset the property values to their original state.
    *
-   * @param string $flag Flag to add.
+   * @return SevenZip The current instance of the SevenZip class.
    */
-  public function addCompressFlag(string $flag): static
+  public function reset(): SevenZip
   {
-    $this->customCompressFlags[] = $flag;
+    $this->customFlags      = [];
+    $this->progressCallback = null;
+    $this->lastProgress     = -1;
+    $this->format           = null;
+    $this->targetPath       = '';
+    $this->sourcePath       = '';
 
     return $this;
   }
 
   /**
-   * Removes a flag from the list of flags.
+   * Set the progress callback using a fluent interface.
+   *
+   * @param callable $callback The callback function to be called during the compression progress.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function progress(callable $callback): static
+  {
+    return $this->setProgressCallback($callback);
+  }
+
+  /**
+   * Set the compression level to faster.
    *
-   * @param string $flag Flag to remove.
+   * @return $this The current instance of the SevenZip class.
    */
-  public function removeCompressFlag(string $flag): static
+  public function faster(): static
   {
-    $index = array_search($flag, $this->customCompressFlags);
-    if ($index !== false) {
-      unset($this->customCompressFlags[$index]);
+    if ($this->getFormat() === 'zstd' || $this->getFormat() === 'zst') {
+      return $this->mx(0);
     }
 
-    return $this;
+    return $this->mx(1);
   }
 
   /**
-   * Defines a callback to be called when the progress changes.
+   * Set the compression level using the -mx flag.
    *
-   * @param callable $callback Função de callback para receber o progresso.
+   * @param int $level The compression level to be used.
+   * @return $this The current instance of the SevenZip class.
    */
-  public function setProgressCallback(callable $callback): static
+  public function mx(int $level): static
   {
-    $this->progressCallback = $callback;
+    return $this->addFlag('mx', $level);
+  }
 
-    return $this;
+  /**
+   * Add a compression flag.
+   *
+   * @param string $flag The compression flag to be added.
+   * @param mixed $value The value for the flag (optional).
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function addFlag(string $flag, $value = null): static
+  {
+    $customFlags        = $this->getCustomFlags();
+    $customFlags[$flag] = $value;
+    return $this->setCustomFlags($customFlags);
+  }
+
+  /**
+   * Set the compression level to slower.
+   *
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function slower(): static
+  {
+    if ($this->getFormat() === 'zstd' || $this->getFormat() === 'zst') {
+      return $this->mx(22);
+    }
+
+    return $this->mx(9);
+  }
+
+  /**
+   * Configures maximum compression settings based on the specified format.
+   *
+   * @return static The current instance for method chaining.
+   */
+  public function ultra(): static
+  {
+    $this->mmt(true)->mx(9);
+
+    return match ($this->getFormat()) {
+      'zip'         => $this->mm('Deflate64')->mfb(257)->mpass(15)->mmem(28),
+      'gzip'        => $this->mfb(258)->mpass(15),
+      'bzip2'       => $this->mpass(7)->md('900000b'),
+      '7z'          => $this->m0('lzma2')->mfb(64)->ms(true)->md('32m'),
+      'zstd', 'zst' => $this->mx(22),
+      default       => $this,
+    };
+  }
+
+  /**
+   * Set the number of CPU threads to use for compression.
+   *
+   * @param int|bool|string $threads The number of CPU threads to use, or 'on' or 'off'.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function mmt(int|bool|string $threads = 'on'): static
+  {
+    if ($threads === true) {
+      $threads = 'on';
+    }
+    if ($threads === false || $threads === 0 || $threads === '0') {
+      $threads = 'off';
+    }
+
+    return $this->addFlag('mmt', $threads);
+  }
+
+  public function mmem(int|string $size = 24)
+  {
+    return $this->addFlag('mmem', $size);
+  }
+
+  /**
+   * Set the number of passes for compression.
+   *
+   * @param int $number The number of passes for compression.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function mpass(int $number = 7): static
+  {
+    return $this->addFlag('mpass', $number);
+  }
+
+  /**
+   * Set the size of the Fast Bytes for the compression algorithm.
+   *
+   * @param int $bytes The size of the Fast Bytes. The default value (when set) is 64.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function mfb(int $bytes = 64): static
+  {
+    return $this->addFlag('mfb', $bytes);
+  }
+
+  /**
+   * Set the compression method for ZIP format
+   *
+   * @param string $method Sets a method: Copy, Deflate, Deflate64, BZip2, LZMA, PPMd.
+   * @return $this
+   */
+  public function mm(string $method = 'Deflate'): static
+  {
+    return $this->addFlag('mm', $method);
+  }
+
+  public function md(string $size = '32m'): static
+  {
+    return $this->addFlag('md', $size);
+  }
+
+  public function ms(bool|string|int $on = true): static
+  {
+    return $this->addFlag('ms', $on ? 'on' : 'off');
+  }
+
+  /**
+   * Set the compression method.
+   * @param $method string The compression method to be used.
+   * @return $this
+   */
+  public function m0($method): static
+  {
+    return $this->addFlag('m0', $method);
+  }
+
+  /*
+   * Sets level of file analysis.
+   *
+   * @param int $level
+   * @return $this
+   */
+
+  /**
+   * Configures no compression (copy only) settings based on the specified format.
+   *
+   * @return static The current instance for method chaining.
+   */
+  public function copy(): static
+  {
+    return $this->mmt(true)->mx(0)->m0('Copy')->mm('Copy')->myx(0);
+  }
+
+  /**
+   * Sets file analysis level.
+   *
+   * @param int $level
+   * @return $this
+   */
+  public function myx(int $level = 5): static
+  {
+    return $this->addFlag('myx', $level);
+  }
+
+  /**
+   * Extract an archive.
+   *
+   * @param ?string $sourcePath Path to the archive (optional).
+   * @param ?string $targetPath Path to extract the archive (optional).
+   * @return bool True on success.
+   * @throws \InvalidArgumentException If source path or target path is not set.
+   *
+   */
+  public function extract(?string $sourcePath = null, ?string $targetPath = null): bool
+  {
+    if ($sourcePath !== null) {
+      $this->setSourcePath($sourcePath);
+    }
+
+    if ($targetPath !== null) {
+      $this->setTargetPath($targetPath);
+    }
+
+    if (!$this->getSourcePath()) {
+      throw new \InvalidArgumentException('Archive path (source) must be set or passed as argument');
+    }
+
+    if (!$this->getTargetPath()) {
+      throw new \InvalidArgumentException('Extract path (target) must be set or passed as argument');
+    }
+
+    $command = [
+      $this->getSevenZipPath(),
+      'x',
+      ...$this->flagrize($this->getAlwaysFlags()),
+      ...$this->flagrize($this->getCustomFlags()),
+      $this->getSourcePath(),
+      '-o' . $this->getTargetPath(),
+    ];
+
+    return $this->runCommand($command);
+  }
+
+  /**
+   * Set the target path for compression/extraction using a fluent interface.
+   *
+   * @param string|null $path The path to the target file or directory for compression or extraction.
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function target(?string $path): static
+  {
+    return $this->setTargetPath($path);
+  }
+
+  /**
+   * Remove a compression flag.
+   *
+   * @param string $flag The compression flag to be removed.
+   *
+   * @return $this The current instance of the SevenZip class.
+   */
+  public function removeFlag(string $flag): static
+  {
+    $customFlags = $this->getCustomFlags();
+
+    unset($customFlags[$flag]);
+
+    return $this->setCustomFlags($customFlags);
   }
 }
diff --git a/test_files/source/Dart HTTP README.md b/test_files/source/Dart HTTP README.md
new file mode 100644
index 0000000..85ec291
--- /dev/null
+++ b/test_files/source/Dart HTTP README.md	
@@ -0,0 +1,292 @@
+[![pub package](https://img.shields.io/pub/v/http.svg)](https://pub.dev/packages/http)
+[![package publisher](https://img.shields.io/pub/publisher/http.svg)](https://pub.dev/packages/http/publisher)
+
+A composable, Future-based library for making HTTP requests.
+
+This package contains a set of high-level functions and classes that make it
+easy to consume HTTP resources. It's multi-platform (mobile, desktop, and
+browser) and supports multiple implementations.
+
+## Using
+
+The easiest way to use this library is via the top-level functions. They allow
+you to make individual HTTP requests with minimal hassle:
+
+```dart
+import 'package:http/http.dart' as http;
+
+var url = Uri.https('example.com', 'whatsit/create');
+var response = await http.post(url, body: {'name': 'doodle', 'color': 'blue'});
+print('Response status: ${response.statusCode}');
+print('Response body: ${response.body}');
+
+print(await http.read(Uri.https('example.com', 'foobar.txt')));
+```
+
+> [!NOTE]
+> Flutter applications may require
+> [additional configuration](https://docs.flutter.dev/data-and-backend/networking#platform-notes)
+> to make HTTP requests.
+
+If you're making multiple requests to the same server, you can keep open a
+persistent connection by using a [Client][] rather than making one-off requests.
+If you do this, make sure to close the client when you're done:
+
+```dart
+var client = http.Client();
+try {
+  var response = await client.post(
+      Uri.https('example.com', 'whatsit/create'),
+      body: {'name': 'doodle', 'color': 'blue'});
+  var decodedResponse = jsonDecode(utf8.decode(response.bodyBytes)) as Map;
+  var uri = Uri.parse(decodedResponse['uri'] as String);
+  print(await client.get(uri));
+} finally {
+  client.close();
+}
+```
+
+> [!TIP]
+> For detailed background information and practical usage examples, see:
+> - [Dart Development: Fetch data from the internet](https://dart.dev/tutorials/server/fetch-data)
+> - [Flutter Cookbook: Fetch data from the internet](https://docs.flutter.dev/cookbook/networking/fetch-data)
+> - [The Flutter HTTP example application][flutterhttpexample]
+
+You can also exert more fine-grained control over your requests and responses by
+creating [Request][] or [StreamedRequest][] objects yourself and passing them to
+[Client.send][].
+
+[Request]: https://pub.dev/documentation/http/latest/http/Request-class.html
+[StreamedRequest]: https://pub.dev/documentation/http/latest/http/StreamedRequest-class.html
+[Client.send]: https://pub.dev/documentation/http/latest/http/Client/send.html
+
+This package is designed to be composable. This makes it easy for external
+libraries to work with one another to add behavior to it. Libraries wishing to
+add behavior should create a subclass of [BaseClient][] that wraps another
+[Client][] and adds the desired behavior:
+
+[BaseClient]: https://pub.dev/documentation/http/latest/http/BaseClient-class.html
+[Client]: https://pub.dev/documentation/http/latest/http/Client-class.html
+
+```dart
+class UserAgentClient extends http.BaseClient {
+  final String userAgent;
+  final http.Client _inner;
+
+  UserAgentClient(this.userAgent, this._inner);
+
+  Future<http.StreamedResponse> send(http.BaseRequest request) {
+    request.headers['user-agent'] = userAgent;
+    return _inner.send(request);
+  }
+}
+```
+
+## Retrying requests
+
+`package:http/retry.dart` provides a class [`RetryClient`][RetryClient] to wrap
+an underlying [`http.Client`][Client] which transparently retries failing
+requests.
+
+[RetryClient]: https://pub.dev/documentation/http/latest/retry/RetryClient-class.html
+[Client]: https://pub.dev/documentation/http/latest/http/Client-class.html
+
+```dart
+import 'package:http/http.dart' as http;
+import 'package:http/retry.dart';
+
+Future<void> main() async {
+  final client = RetryClient(http.Client());
+  try {
+    print(await client.read(Uri.http('example.org', '')));
+  } finally {
+    client.close();
+  }
+}
+```
+
+By default, this retries any request whose response has status code 503
+Temporary Failure up to three retries. It waits 500ms before the first retry,
+and increases the delay by 1.5x each time. All of this can be customized using
+the [`RetryClient()`][new RetryClient] constructor.
+
+[new RetryClient]: https://pub.dev/documentation/http/latest/retry/RetryClient/RetryClient.html
+
+## Choosing an implementation
+
+There are multiple implementations of the `package:http` [`Client`][client] interface. By default, `package:http` uses [`BrowserClient`][browserclient] on the web and [`IOClient`][ioclient] on all other platforms. You an choose a different [`Client`][client] implementation based on the needs of your application.
+
+You can change implementations without changing your application code, except
+for a few lines of [configuration](#2-configure-the-http-client).
+
+Some well supported implementations are:
+
+| Implementation | Supported Platforms | SDK | Caching | HTTP3/QUIC | Platform Native | 
+| -------------- | ------------------- | ----| ------- | ---------- | --------------- |
+| `package:http` — [`IOClient`][ioclient] | Android, iOS, Linux, macOS, Windows | Dart, Flutter | ❌ | ❌ | ❌ |
+| `package:http` — [`BrowserClient`][browserclient] | Web | Dart, Flutter | ― | ✅︎ | ✅︎ | Dart, Flutter |
+| [`package:cupertino_http`][cupertinohttp] — [`CupertinoClient`][cupertinoclient] | iOS, macOS | Flutter | ✅︎ | ✅︎ | ✅︎ |
+| [`package:cronet_http`][cronethttp] — [`CronetClient`][cronetclient] | Android | Flutter | ✅︎ | ✅︎ | ― |
+| [`package:fetch_client`][fetch] — [`FetchClient`][fetchclient] | Web | Dart, Flutter | ✅︎ | ✅︎ | ✅︎ |
+
+> [!TIP]
+> If you are writing a Dart package or Flutter pluggin that uses
+> `package:http`, you should not depend on a particular [`Client`][client]
+> implementation. Let the application author decide what implementation is
+> best for their project. You can make that easier by accepting an explicit
+> [`Client`][client] argument. For example:
+>
+> ```dart
+> Future<Album> fetchAlbum({Client? client}) async {
+>   client ??= Client();
+>   ...
+> }
+> ```
+
+## Configuration
+
+To use a HTTP client implementation other than the default, you must:
+1. Add the HTTP client as a dependency.
+2. Configure the HTTP client.
+3. Connect the HTTP client to the code that uses it.
+
+### 1. Add the HTTP client as a dependency.
+
+To add a package compatible with the Dart SDK to your project, use `dart pub add`.
+
+For example:
+
+```terminal
+# Replace  "fetch_client" with the package that you want to use.
+dart pub add fetch_client
+```
+
+To add a package that requires the Flutter SDK, use `flutter pub add`.
+
+For example:
+
+```terminal
+# Replace  "cupertino_http" with the package that you want to use.
+flutter pub add cupertino_http
+```
+
+### 2. Configure the HTTP client.
+
+Different `package:http` [`Client`][client] implementations may require
+different configuration options.
+
+Add a function that returns a correctly configured [`Client`][client]. You can
+return a different [`Client`][client] on different platforms.
+
+For example:
+
+```dart
+Client httpClient() {
+  if (Platform.isAndroid) {
+    final engine = CronetEngine.build(
+        cacheMode: CacheMode.memory,
+        cacheMaxSize: 1000000);
+    return CronetClient.fromCronetEngine(engine);
+  }
+  if (Platform.isIOS || Platform.isMacOS) {
+    final config = URLSessionConfiguration.ephemeralSessionConfiguration()
+      ..cache = URLCache.withCapacity(memoryCapacity: 1000000);
+    return CupertinoClient.fromSessionConfiguration(config);
+  }
+  return IOClient();
+}
+```
+
+> [!TIP]
+> [The Flutter HTTP example application][flutterhttpexample] demonstrates
+> configuration best practices.
+
+#### Supporting browser and native
+
+If your application can be run in the browser and natively, you must put your
+browser and native configurations in seperate files and import the correct file
+based on the platform.
+
+For example:
+
+```dart
+// -- http_client_factory.dart
+Client httpClient() {
+  if (Platform.isAndroid) {
+    return CronetClient.defaultCronetEngine();
+  }
+  if (Platform.isIOS || Platform.isMacOS) {
+    return CupertinoClient.defaultSessionConfiguration();
+  }
+  return IOClient();
+}
+```
+
+```dart
+// -- http_client_factory_web.dart
+Client httpClient() => FetchClient();
+```
+
+```dart
+// -- main.dart
+import 'http_client_factory.dart'
+    if (dart.library.js_interop) 'http_client_factory_web.dart'
+
+// The correct `httpClient` will be available.
+```
+
+### 3. Connect the HTTP client to the code that uses it.
+
+The best way to pass [`Client`][client] to the places that use it is
+explicitly through arguments.
+
+For example:
+
+```dart
+void main() {
+  final client = httpClient();
+  fetchAlbum(client, ...);
+}
+```
+
+In Flutter, you can use a one of many
+[state mangement approaches][flutterstatemanagement].
+
+If you depend on code that uses top-level functions (e.g. `http.post`) or
+calls the [`Client()`][clientconstructor] constructor, then you can use
+[`runWithClient`](runwithclient) to ensure that the correct
+`Client` is used. When an [Isolate][isolate] is spawned, it does not inherit
+any variables from the calling Zone, so `runWithClient` needs to be used in
+each Isolate that uses `package:http`.
+
+You can ensure that only the `Client` that you have explicitly configured is
+used by defining `no_default_http_client=true` in the environment. This will
+also allow the default `Client` implementation to be removed, resulting in
+a reduced application size.
+
+```terminal
+$ flutter build appbundle --dart-define=no_default_http_client=true ...
+$ dart compile exe --define=no_default_http_client=true ...
+```
+
+> [!TIP]
+> [The Flutter HTTP example application][flutterhttpexample] demonstrates
+> how to make the configured [`Client`][client] available using
+> [`package:provider`][provider] and [`package:http_image_provider`][http_image_provider].
+
+[browserclient]: https://pub.dev/documentation/http/latest/browser_client/BrowserClient-class.html
+[client]: https://pub.dev/documentation/http/latest/http/Client-class.html
+[clientconstructor]: https://pub.dev/documentation/http/latest/http/Client/Client.html
+[cupertinohttp]: https://pub.dev/packages/cupertino_http
+[cupertinoclient]: https://pub.dev/documentation/cupertino_http/latest/cupertino_http/CupertinoClient-class.html
+[cronethttp]: https://pub.dev/packages/cronet_http
+[cronetclient]: https://pub.dev/documentation/cronet_http/latest/cronet_http/CronetClient-class.html
+[fetch]: https://pub.dev/packages/fetch_client
+[fetchclient]: https://pub.dev/documentation/fetch_client/latest/fetch_client/FetchClient-class.html
+[flutterhttpexample]: https://github.com/dart-lang/http/tree/master/pkgs/flutter_http_example
+[http_image_provider]: https://pub.dev/documentation/http_image_provider
+[ioclient]: https://pub.dev/documentation/http/latest/io_client/IOClient-class.html
+[isolate]: https://dart.dev/language/concurrency#how-isolates-work
+[flutterstatemanagement]: https://docs.flutter.dev/data-and-backend/state-mgmt/options
+[provider]: https://pub.dev/packages/provider
+[runwithclient]: https://pub.dev/documentation/http/latest/http/runWithClient.html
diff --git a/test_files/source/Dart JS.md b/test_files/source/Dart JS.md
new file mode 100644
index 0000000..062666a
--- /dev/null
+++ b/test_files/source/Dart JS.md	
@@ -0,0 +1,76 @@
+---
+title: JavaScript interoperability
+short-title: JS interop
+description: Integrate JavaScript code into your Dart web app.
+---
+
+The [Dart web platform](/overview#web-platform) supports communication with
+JavaScript apps and libraries, as well as browser APIs, using `dart:js_interop`.
+
+Web developers can benefit from using external JS libraries in their Dart code,
+without having to rewrite anything in Dart.
+
+## Next-generation JS interop
+
+The Dart team [recently][] overhauled the collection of features and APIs that allow
+developers access to JavaScript and browser bindings in their Dart code.
+This next generation of web interop not only improves user experience,
+but also enables [Wasm][] support, aligning Dart with the future of the Web.
+
+The following table maps Dart's new JS and web interop solutions to
+their past counterparts:
+
+<div class="table-wrapper" markdown="1">
+
+| New interop libraries        | Previous libraries                       |
+|------------------------------|------------------------------------------|
+| [`package:web`][] | [`dart:html`][] <br> [`dart:indexed_db`][] <br> [`dart:svg`][] <br> [`dart:web_audio`][] <br> [`dart:web_gl`][] |
+| [`dart:js_interop`][] <br> [`dart:js_interop_unsafe`][] | [`package:js`][] <br> [`dart:js`][] <br> [`dart:js_util`][] |
+
+{:.table .table-striped}
+</div>
+
+The Dart interop story has been under heavy development for some time now;
+check out the [Past JS interop][] page for a more in depth summary on past
+iterations.
+
+[recently]: https://medium.com/dartlang/dart-3-3-325bf2bf6c13
+[Wasm]: {{site.flutter-docs}}/platform-integration/web/wasm
+[`package:web`]: {{site.pub-pkg}}/web
+[`dart:html`]: {{site.dart-api}}/dev/dart-html/dart-html-library.html
+[`dart:svg`]: {{site.dart-api}}/dev/dart-svg/dart-svg-library.html
+[`dart:indexed_db`]: {{site.dart-api}}/dev/dart-indexed_db/dart-indexed_db-library.html
+[`dart:web_audio`]: {{site.dart-api}}/dev/dart-web_audio/dart-web_audio-library.html
+[`dart:web_gl`]: {{site.dart-api}}/dev/dart-web_gl/dart-web_gl-library.html
+[`dart:js_interop`]: {{site.dart-api}}/dev/dart-js_interop/dart-js_interop-library.html
+[`dart:js_interop_unsafe`]: {{site.dart-api}}/dev/dart-js_interop_unsafe/dart-js_interop_unsafe-library.html
+[`package:js`]: {{site.pub-api}}/js
+[`dart:js`]: {{site.dart-api}}/dev/dart-js/dart-js-library.html
+[`dart:js_util`]: {{site.dart-api}}/dev/dart-js_util/dart-js_util-library.html
+[Past JS interop]: /interop/js-interop/past-js-interop/
+## Overview
+
+For information on how to write and use JavaScript interop:
+  * [Usage reference]
+  * [JS types reference]
+
+For information on interacting with web APIs:
+  * [`package:web` and migration]
+
+For tutorials and help:
+  * [How to mock JavaScript interop objects]
+
+For information on previous JavaScript interop libraries:
+  * [Past JS interop]
+
+For additional documentation on JavaScript interop:
+  * [`dart:js_interop` API reference]
+  * [`dart:js_interop_unsafe` API reference]
+
+[Usage reference]: /interop/js-interop/usage
+[JS types reference]: /interop/js-interop/js-types
+[`package:web` and migration]: /interop/js-interop/package-web
+[How to mock JavaScript interop objects]: /interop/js-interop/mock
+[Past JS interop]: /interop/js-interop/past-js-interop
+[`dart:js_interop` API reference]: {{site.dart-api}}/dev/dart-js_interop/dart-js_interop-library.html
+[`dart:js_interop_unsafe` API reference]: {{site.dart-api}}/dev/dart-js_interop_unsafe/dart-js_interop_unsafe-library.html
diff --git a/test_files/source/Dart Language Evolution.md b/test_files/source/Dart Language Evolution.md
new file mode 100644
index 0000000..d59666d
--- /dev/null
+++ b/test_files/source/Dart Language Evolution.md	
@@ -0,0 +1,608 @@
+---
+title: Dart language evolution
+short-title: Language evolution
+description: Notable changes and additions to the Dart programming language.
+---
+
+This page lists notable changes and additions to the
+Dart programming language.
+
+* To learn specific details about the most recent supported language version,
+  check out the [language documentation][] or the [language specification][].
+* For a full history of changes to the Dart SDK, see the [SDK changelog][].
+* For a full history of breaking changes,
+  including [language versioned][] changes,
+  check out the [Breaking changes][] page.
+
+To use a language feature introduced after 2.0,
+set an [SDK constraint][] no lower than
+the release when Dart first supported that feature.
+
+**For example:** To use null safety, introduced in [2.12][],
+set `2.12.0` as the lower constraint in the `pubspec.yaml` file.
+
+```yaml
+environment:
+  sdk: '>=2.12.0 <3.0.0'
+```
+
+[2.12]: #dart-2-12
+[SDK constraint]: /tools/pub/pubspec#sdk-constraints
+[language versioned]: #language-versioning
+[Breaking changes]: /resources/breaking-changes
+
+:::tip
+To review the features being discussed, investigated, and
+added to the Dart language,
+check out the [language funnel][] tracker
+on the Dart language GitHub repo.
+:::
+
+
+## Changes in each release
+
+### Dart 3.3
+_Released 15 February 2024_
+| [Dart 3.3 announcement](https://medium.com/dartlang/dart-3-3-325bf2bf6c13)
+
+Dart 3.3 added some enchancements to the language:
+
+* [Extension types][] are a new feature in Dart that allow zero-cost wrapping
+  of an existing type. They are similar to wrapper classes and extension methods,
+  but with implementation differences and different tradeoffs.
+
+  ```dart
+  extension type Meters(int value) {
+    String get label => '${value}m';
+    Meters operator +(Meters other) => Meters(value + other.value);
+  }
+
+  void main() {
+    var m = Meters(42); // Has type `Meters`.
+    var m2 = m + m; // OK, type `Meters`.
+    // int i = m; // Compile-time error, wrong type.
+    // m.isEven; // Compile-time error, no such member.
+    assert(identical(m, m.value)); // Succeeds.
+  }
+  ```
+
+* Abstract getters are now promotable under the rules of
+  [private final field promotion][], if there are no conflicting declarations.
+
+### Dart 3.2
+_Released 15 November 2023_
+| [Dart 3.2 announcement](https://medium.com/dartlang/dart-3-2-c8de8fe1b91f)
+
+Dart 3.2 added enhancements to flow analysis, including:
+
+* Expanded [type promotion](/null-safety/understanding-null-safety#type-promotion-on-null-checks)
+  to work on private final fields. Previously only available for
+  local variables and parameters, now private final fields can promote to
+  non-nullable types through null checks and `is` tests. For example,
+  the following code is now sound:
+
+  ```dart
+  class Example {
+    final int? _privateField;
+  
+    Example(this._privateField);
+  
+    void f() {
+      if (_privateField != null) {
+        // _privateField has now been promoted; you can use it without
+        // null checking it.
+        int i = _privateField; // OK
+      }
+    }
+  }
+  
+  // Private field promotions also work from outside of the class:
+  void f(Example x) {
+    if (x._privateField != null) {
+      int i = x._privateField; // OK
+    }
+  }
+  ```
+  
+  For more information on when private final fields can and can't promote, check
+  out [Fixing type promotion failures](/tools/non-promotion-reasons).
+
+* Corrected inconsistencies in type promotion behavior of
+  [if-case](/language/branches#if-case) statements
+  where the value being matched against throws an exception.
+
+
+### Dart 3.1
+_Released 16 August 2023_
+| [Dart 3.1 announcement](https://medium.com/dartlang/dart-3-1-a-retrospective-on-functional-style-programming-in-dart-3-a1f4b3a7cdda)
+
+Dart 3.1 added no new features and made no changes to the language.
+
+### Dart 3.0
+_Released 10 May 2023_
+| [Dart 3.0 announcement](https://medium.com/dartlang/announcing-dart-3-53f065a10635)
+
+Dart 3.0 introduced several new major language features:
+
+* [Patterns][], a new category of grammar that lets you
+  match and destructure values.
+* [Records][], a new type that lets you aggregate
+  multiple values of different types in a single function return.
+* [Class modifiers][], a new set of keywords that let you
+  control how a class or mixin can be used.
+* [Switch expressions][], a new form of multi-way branching
+  allowed where expressions are expected.
+* [If-case clauses][], a new conditional construct that matches a value
+  against a pattern and executes the then or else branch, depending
+  on whether the pattern matches.
+
+Dart 3.0 also introduced a few breaking language changes:
+
+* Class declarations without the [`mixin`][] class modifier
+  can no longer be applied as mixins.
+* It is now a compile time error if a colon (`:`) is used as the separator
+  before the default value of an optional named parameter.
+  Use an equal sign (`=`) instead.
+* It is now a compile-time error if a `continue` statement targets a
+  label that is not attached to a
+  loop statement (`for`, `do`, and `while`) or a `switch` member.
+
+:::note
+The 3.0 release of the Dart SDK dropped support for
+[language versions][] before 2.12.
+:::
+
+[Patterns]: /language/patterns
+[Records]: /language/records
+[Class modifiers]: /language/class-modifiers
+[Switch expressions]: /language/branches#switch-expressions
+[If-case clauses]: /language/branches#if-case
+[`mixin`]: /language/mixins#class-mixin-or-mixin-class
+[language versions]: #language-versioning
+
+### Dart 2.19
+_Released 25 January 2023_
+
+Dart 2.19 introduced some precautions surrounding type inference.
+These include:
+
+* More flow analysis flags for unreachable code cases.
+* No longer delegate inaccessible private names to `noSuchMethod`.
+* Top-level type inference throws on cyclic dependencies.
+
+Dart 2.19 also introduced support for unnamed libraries.
+Library directives, used for appending library-level doc comments and
+annotations, can and [should][] now be written without a name:
+
+```dart
+/// A really great test library.
+@TestOn('browser')
+library;
+```
+
+[should]: /effective-dart/style#dont-explicitly-name-libraries
+
+### Dart 2.18
+_Released 30 August 2022_
+| [Dart 2.18 announcement](https://medium.com/dartlang/dart-2-18-f4b3101f146c)
+
+Dart 2.18 enhanced type inference.
+This change allows information flow between arguments in generic function calls.
+Before 2.18, if you didn't specify an argument's type in some methods,
+Dart reported errors.
+These type errors cited potential null occurrences.
+With 2.18, the compiler infers the argument type
+from other values in an invocation.
+You don't need to specify the argument type inline.
+
+Dart 2.18 also discontinued support for mixin classes that don't extend
+`Object`.
+
+To learn more about these features, check out:
+
+* [Type argument inference][]
+* [Adding features to a class: mixins][]
+
+[Type argument inference]: /language/type-system#type-argument-inference
+[Adding features to a class: mixins]: /language/mixins
+
+### Dart 2.17
+_Released 11 May 2022_
+| [Dart 2.17 announcement](https://medium.com/dartlang/dart-2-17-b216bfc80c5d)
+
+Dart 2.17 expanded enum functionality with enhanced enums.
+Enhanced enums allow enum declarations to define members
+including fields, constructors, methods, getters, etc.
+
+Dart 2.17 added support for super-initializer parameters in
+constructors.
+Super parameters allow you to avoid having to manually pass each
+parameter into the super invocation of a non-redirecting constructor.
+You can instead use super parameters to forward parameters to a
+superclass constructor.
+
+Dart 2.17 removed some restrictions on named arguments.
+Named arguments can now be freely interleaved with positional arguments.
+As of Dart 2.17, you can write the following code:
+
+```dart
+void main() {
+  test(skip: true, 'A test description', () {
+    // Very long function body here...
+  });
+}
+```
+
+To learn more about these features, check out:
+
+* [Enhanced enums][]
+* [Super parameters][]
+* [Named parameters][]
+
+[Enhanced enums]: /language/enums#declaring-enhanced-enums
+[Super parameters]: /language/constructors#super-parameters
+[Named parameters]: /language/functions#named-parameters
+
+### Dart 2.16
+_Released 3 February 2022_
+| [Dart 2.16 announcement](https://medium.com/dartlang/dart-2-15-7e7a598e508a)
+
+Dart 2.16 added no new features to the Dart language.
+It did expand the Dart tools.
+
+### Dart 2.15
+_Released 8 December 2021_
+| [Dart 2.15 announcement](https://medium.com/dartlang/dart-2-15-7e7a598e508a)
+
+Dart 2.15 improved support for function pointers, known as _tear-offs._
+In particular, constructor tear-offs are now supported.
+
+### Dart 2.14
+_Released 8 September 2021_
+| [Dart 2.14 announcement](https://medium.com/dartlang/announcing-dart-2-14-b48b9bb2fb67)
+
+Dart 2.14 added the unsigned shift (or _triple-shift_) operator (`>>>`).
+This new operator works like `>>`,
+except that it always fills the most significant bits with zeros.
+
+To learn more about these operators, check out [bitwise and shift operators][].
+
+[bitwise and shift operators]: /language/operators#bitwise-and-shift-operators
+
+Dart 2.14 removed some restrictions on type arguments.
+You can pass type arguments to annotations and use a generic function
+type as a type argument.
+As of Dart 2.14, you can write the following code:
+
+```dart
+@TypeHelper<int>(42, "The meaning")
+late List<T Function<T>(T)> idFunctions;
+var callback = [<T>(T value) => value];
+late S Function<S extends T Function<T>(T)>(S) f;
+```
+
+### Dart 2.13
+_Released 19 May 2021_
+| [Dart 2.13 announcement](https://medium.com/dartlang/announcing-dart-2-13-c6d547b57067)
+
+Dart 2.13 expanded support for **[type aliases][]** (`typedef`).
+Type aliases used to work only for function types
+but now work for any type.
+You can use the new name created with a type alias
+anywhere the original type could be used.
+
+Dart 2.13 improved the struct support in **[Dart FFI][]**,
+adding support for inline arrays and packed structs.
+
+### Dart 2.12
+_Released 3 March 2021_
+| [Dart 2.12 announcement](https://medium.com/dartlang/announcing-dart-2-12-499a6e689c87)
+
+Dart 2.12 added support for **[sound null safety][]**.
+When you opt into null safety, types in your code are non-nullable by default,
+meaning that variables can't contain null unless you say they can.
+With null safety, your runtime null-dereference errors
+turn into edit-time analysis errors.
+
+In Dart 2.12, **[Dart FFI][]** graduated from beta to the stable channel.
+
+### Dart 2.10
+_Released 1 October 2020_
+| [Dart 2.10 announcement](https://medium.com/dartlang/announcing-dart-2-10-350823952bd5)
+
+Dart 2.10 added no new features to the Dart language.
+
+### Dart 2.9
+_Released 5 August 2020_
+
+Dart 2.9 added no new features to the Dart language.
+
+### Dart 2.8
+_Released 6 May 2020_
+| [Dart 2.8 announcement](https://medium.com/dartlang/announcing-dart-2-8-7750918db0a)
+
+Dart 2.8 didn't add any features to the Dart language. It did
+contain a number of preparatory [breaking changes][2.8 breaking changes]
+to improve nullability-related usability and performance for [null safety][].
+
+### Dart 2.7
+_Released 11 December 2019_
+| [Dart 2.7 announcement](https://medium.com/dartlang/dart-2-7-a3710ec54e97)
+
+Dart 2.7 added support for **[extension methods][]**,
+enabling you to add functionality to any type
+—-even types you don't control—-
+with the brevity and auto-complete experience of regular method calls.
+
+The following example extends the `String` class from
+`dart:core` with a new `parseInt()` method:
+
+```dart
+extension ParseNumbers on String {
+  int parseInt() {
+    return int.parse(this);
+  }
+}
+
+void main() {
+  int i = '42'.parseInt();
+  print(i);
+}
+```
+
+### Dart 2.6
+_Released 5 November 2019_
+| [Dart 2.6 announcement](https://medium.com/dartlang/dart2native-a76c815e6baf)
+
+Dart 2.6 introduced a
+[breaking change (dart-lang/sdk#37985)](https://github.com/dart-lang/sdk/issues/37985).
+Constraints where `Null` serves as a subtype of `FutureOr<T>`
+now yield `Null` as the solution for `T`.
+
+For example: The following code now prints `Null`.
+Before Dart 2.6, it printed `dynamic`.
+The anonymous closure `() {}` returns the `Null` type.
+
+```dart
+import 'dart:async';
+
+void foo<T>(FutureOr<T> Function() f) { print(T); }
+
+main() { foo(() {}); }
+```
+
+### Dart 2.5
+_Released 10 September 2019_
+| [Dart 2.5 announcement](https://medium.com/dartlang/announcing-dart-2-5-super-charged-development-328822024970)
+
+Dart 2.5 didn't add any features to the Dart language, but it did add
+support for [calling native C code][] from Dart code
+using a new **core library, `dart:ffi`.**
+
+### Dart 2.4
+_Released 27 June 2019_
+
+
+Dart 2.4 introduces a breaking change
+[dart-lang/sdk#35097](https://github.com/dart-lang/sdk/issues/35097).
+
+Dart now enforces covariance of type variables used in super-interfaces.
+For example: Prior to this release Dart accepted, but now rejects,
+the following code:
+
+```dart
+class A<X> {};
+class B<X> extends A<void Function(X)> {};
+```
+
+You can now use `async` as an identifier in
+asynchronous and generator functions.
+
+### Dart 2.3
+_Released 8 May 2019_
+| [Dart 2.3 announcement](https://medium.com/dartlang/announcing-dart-2-3-optimized-for-building-user-interfaces-e84919ca1dff)
+
+Dart 2.3 added three operators designed to improve code that performs
+list manipulation, such as declarative UI code.
+
+The **[spread operator][]**
+enables unpacking the elements from one list into another.
+In the following example, the list returned by `buildMainElements()`
+is unpacked into the list being passed to the `children` argument:
+
+```dart
+Widget build(BuildContext context) {
+  return Column(children: [
+    Header(),
+    ...buildMainElements(),
+    Footer(),
+  ]);
+}
+```
+
+The **[collection if][]** operator enables adding elements conditionally.
+The following example adds a `FlatButton` element unless
+the app displays the last page:
+
+```dart
+Widget build(BuildContext context) {
+  return Column(children: [
+    Text(mainText),
+    if (page != pages.last)
+      FlatButton(child: Text('Next')),
+  ]);
+}
+```
+
+The **[collection for][]** operator enables building repeated elements.
+The following example adds one `HeadingAction` element for
+each section in `sections`:
+
+```dart
+Widget build(BuildContext context) {
+  return Column(children: [
+    Text(mainText),
+    for (var section in sections)
+      HeadingAction(section.heading),
+  ]);
+}
+```
+
+
+### Dart 2.2
+_Released 26 February 2019_
+| [Dart 2.2 announcement](https://medium.com/dartlang/announcing-dart-2-2-faster-native-code-support-for-set-literals-7e2ab19cc86d)
+
+Dart 2.2 added support for **[set literals][]**:
+
+```dart
+const Set<String> currencies = {'EUR', 'USD', 'JPY'};
+```
+
+### Dart 2.1
+_Released 15 November 2018_
+| [Dart 2.1 announcement](https://medium.com/dartlang/announcing-dart-2-1-improved-performance-usability-9f55fca6f31a)
+
+Dart 2.1 added support for **int-to-double conversion**,
+allowing developers to set `double` values using integer literals.
+This feature removed the annoyance of being forced to use a
+`double` literal (for example, `4.0`)
+when the value was an integer in concept.
+
+In the following Flutter code, `horizontal` and `vertical` have type `double`:
+
+```dart
+padding: const EdgeInsets.symmetric(
+  horizontal: 4,
+  vertical: 8,
+)
+```
+
+### Dart 2.0
+_Released 22 February 2018_
+| [Dart 2.0 announcement](https://medium.com/dartlang/announcing-dart-2-80ba01f43b6)
+
+Dart 2.0 implemented a new **[sound type system][]**.
+Before Dart 2.0, types weren't fully sound, and
+Dart relied heavily on runtime type checking.
+Dart 1.x code had to be migrated to Dart 2.
+
+## Language versioning
+
+A single Dart SDK can simultaneously support
+multiple versions of the Dart language.
+The compiler determines what version the code is targeting,
+and it interprets the code according to that version.
+
+Language versioning becomes important on the rare occasions when Dart
+introduces an incompatible feature like [null safety][].
+When Dart introduces a breaking change, code that
+did compile might no longer compile.
+Language versioning allows you to set each library's language version
+to maintain compatibility.
+
+In the case of null safety, Dart SDKs 2.12 through 2.19 allowed you
+to _choose_ to update your code to use null safety.
+Dart uses language versioning to permit non-null-safe code to run
+alongside null-safe code.
+This decision enabled migration from non-null-safe to null-safe code.
+To review an example of how an app or package can migrate to a new
+language version with an incompatible feature, check out
+[Migrating to null safety](/null-safety/migration-guide).
+
+Each package has a default language version equal to the **lower bound**
+of the SDK constraint in the `pubspec.yaml` file.
+
+**For example:** The following entry in a `pubspec.yaml` file
+indicates that this package defaults to the Dart 2.18 language version.
+
+```yaml
+environment:
+  sdk: '>=2.18.0 <3.0.0'
+```
+
+### Language version numbers
+
+Dart formats its language versions as two numbers separated with a period.
+It reads as a major version number and a minor version number.
+Minor version numbers might introduce breaking changes.
+
+Dart releases might append a patch number to a language version.
+Patches should not change the language except for bug fixes.
+To illustrate: Dart 2.18.3 serves as the latest release of the
+Dart 2.18 SDK language version.
+
+Each Dart SDK supports all of the language versions within
+its major version number.
+That means that Dart SDK 2.18.3 supports language versions
+2.0 through 2.18 inclusive, but not Dart 1.x.
+
+Deriving the language version from the SDK version implies the following:
+
+* Whenever a minor version of the SDK ships, a new language version appears.
+  In practice, many of these language versions work in a very similar manner
+  to previous versions and have with full compatibility between them.
+  For example: The Dart 2.9 language works much like the Dart 2.8 language.
+
+* When a patch release of the SDK ships,
+  it cannot introduce new language features.
+  For example: The 2.18.3 release _remains_ language version 2.18.
+  It must remain compatible with 2.18.2, 2.18.1, and 2.18.0.
+
+### Per-library language version selection
+
+By default, every Dart file in a package uses the same language version.
+Dart identifies the default language version as the
+lower-bound of the SDK constraint specified in the `pubspec.yaml` file.
+Sometimes, a Dart file might need to use an older language version.
+For example, you might not be able to migrate all the files in a package
+to null safety at the same time.
+
+Dart supports per-library language version selection.
+To opt to have a different language version from
+the rest of a package, a [Dart library][] must
+include a comment in the following format:
+
+```dart
+// @dart = <major>.<minor>
+```
+
+For example:
+
+```dart
+// Description of what's in this file.
+// @dart = 2.17
+import 'dart:math';
+...
+```
+
+The `@dart` string must be in a `//` comment (not `///` or `/*`),
+and it must appear before any Dart code in the file.
+Whitespace (tabs and spaces) doesn't matter,
+except within the `@dart` and version strings.
+As the previous example shows,
+other comments can appear before the `@dart` comment.
+
+To learn how and why the Dart team developed this versioning method,
+check out the [language versioning specification][].
+
+[2.8 breaking changes]: https://github.com/dart-lang/sdk/issues/40686
+[calling native C code]: /interop/c-interop
+[collection for]: /language/collections#control-flow-operators
+[collection if]: /language/collections#control-flow-operators
+[Dart library]: /guides/libraries/create-packages#organizing-a-package
+[Dart FFI]: /interop/c-interop
+[extension methods]: /language/extension-methods
+[Extension types]: /language/extension-types
+[language funnel]: https://github.com/dart-lang/language/projects/1
+[language specification]: /guides/language/spec
+[language documentation]: /language
+[language versioning specification]: https://github.com/dart-lang/language/blob/main/accepted/2.8/language-versioning/feature-specification.md#dart-language-versioning
+[null safety]: /null-safety
+[private final field promotion]: /tools/non-promotion-reasons
+[SDK changelog]: https://github.com/dart-lang/sdk/blob/main/CHANGELOG.md
+[set literals]: /language/collections#sets
+[sound null safety]: /null-safety
+[sound type system]: /language/type-system
+[spread operator]: /language/collections#spread-operators
+[type aliases]: /language/typedefs
diff --git a/test_files/source/Dart SDK.md b/test_files/source/Dart SDK.md
new file mode 100644
index 0000000..52323af
--- /dev/null
+++ b/test_files/source/Dart SDK.md	
@@ -0,0 +1,9325 @@
+## 3.4.0
+
+### Language
+
+Dart 3.4 makes improvements to the type analysis of conditional expressions
+(`e1 ? e2 : e3`), if-null expressions (`e1 ?? e2`), if-null assignments
+(`e1 ??= e2`), and switch expressions (`switch (e) { p1 => e1, ... }`). To take
+advantage of these improvements, set your package's
+[SDK constraint][language version] lower bound to 3.4 or greater
+(`sdk: '^3.4.0'`).
+
+[language version]: https://dart.dev/guides/language/evolution
+
+- **Breaking Change** [#54640][]: The pattern context type schema for
+  cast patterns has been changed from `Object?` to `_` (the unknown
+  type), to align with the specification. This change is not expected
+  to make any difference in practice.
+
+- **Breaking Change** [#54828][]: The type schema used by the compiler front end
+  to perform type inference on the operand of a null-aware spread operator
+  (`...?`) in map and set literals has been made nullable, to match what
+  currently happens in list literals. This makes the compiler front end behavior
+  consistent with that of the analyzer. This change is expected to be very low
+  impact.
+
+[#54640]: https://github.com/dart-lang/sdk/issues/54640
+[#54828]: https://github.com/dart-lang/sdk/issues/54828
+
+### Libraries
+
+#### `dart:cli`
+
+- **Breaking change** [#52121][]: `waitFor` is removed in 3.4.
+
+#### `dart:io`
+
+- **Breaking change** [#53863][]: `Stdout` has a new field `lineTerminator`,
+  which allows developers to control the line ending used by `stdout` and
+  `stderr`. Classes that `implement Stdout` must define the `lineTerminator`
+  field. The default semantics of `stdout` and `stderr` are not changed.
+
+[#53863]: https://github.com/dart-lang/sdk/issues/53863
+
+#### `dart:js_interop`
+
+- Fixes an issue with several comparison operators in `JSAnyOperatorExtension`
+  that were declared to return `JSBoolean` but really returned `bool`. This led
+  to runtime errors when trying to use the return values. Their return types are
+  now `bool` for convenience. See issues [#55024] for more details.
+
+[#55024]: https://github.com/dart-lang/sdk/issues/55024
+
+### Tools
+
+#### Pub
+
+- Dependency resolution and `dart pub outdated` will now surface if a dependency
+  is affected by a security advisory, unless the advisory is listed under a
+  `ignored_advisories` section in the `pubspec.yaml` file. To learn more about
+  pub's support for security advisories, visit
+  [dart.dev/go/pub-security-advisories][pub-security-advisories].
+- New command `dart pub unpack` that downloads a package from pub.dev and
+  extracts it to a subfolder of the current directory.
+
+  This can be useful for inspecting the code, or playing with examples.
+
+[pub-security-advisories]: https://dart.dev/go/pub-security-advisories
+
+### Libraries
+
+#### `dart:async`
+
+- Added option for `ParallelWaitError` to get some meta-information that
+  it can expose in its `toString`, and the `Iterable<Future>.wait` and
+  `(Future,...,Future).wait` extension methods now provide that information.
+  Should make a `ParallelWaitError` easier to log.
+
+#### `dart:ffi`
+
+- Added `Struct.create` and `Union.create` to create struct and union views
+  of the sequence of bytes stored in a subtype of `TypedData`.
+
+#### `dart:js_interop`
+
+- On dart2wasm, `JSBoxedDartObject` now is an actual JS object that wraps the
+  opaque Dart value instead of only externalizing the value. Like the JS
+  backends, you'll now get a more useful error when trying to use it in another
+  Dart runtime.
+- Added `isA` helper to make type checks easier with interop types. See
+  [#54138][] for more details.
+
+[#54138]: https://github.com/dart-lang/sdk/issues/54138
+
+#### `dart:typed_data`
+
+- **BREAKING CHANGE** [#53218][] [#53785][]: The unmodifiable view classes for
+  typed data are deprecated.
+
+  To create an unmodifiable view of a typed-data object, use the
+  `asUnmodifiableView()` methods added in Dart 3.3:
+
+  ```dart
+  Uint8List data = ...;
+  final readOnlyView = data.asUnmodifiableView();
+  // readOnlyView has type Uint8List, and throws if attempted modified.
+  ```
+
+  The reason for this change is to allow more flexibility in the implementation
+  of typed data, so the native and web platforms can use different strategies
+  to ensure that typed data has good performance.
+
+  The deprecated types will be removed in Dart 3.5.
+
+[#53218]: https://github.com/dart-lang/sdk/issues/53218
+[#53785]: https://github.com/dart-lang/sdk/issues/53785
+
+### Dart Runtime
+- Dart VM flags and options can now be provided to any executable
+  generated using `dart compile exe` via the `DART_VM_OPTIONS` environment
+  variable. `DART_VM_OPTIONS` should be set to a list of comma-separated flags
+  and options with no whitespace. Options that allow for multiple values to be
+  provided as comma-separated values are not supported
+  (e.g., `--timeline-streams=Dart,GC,Compiler`).
+
+  Example of a valid `DART_VM_OPTIONS` environment variable:
+
+  ```bash
+  DART_VM_OPTIONS=--random_seed=42,--verbose_gc
+  ```
+
+### Tools
+
+#### DevTools
+
+- Updated DevTools to version 2.33.0 from 2.31.1.
+  To learn more, check out the release notes for versions
+  [2.32.0][devtools-2-32-0] and [2.33.0][devtools-2-33-0].
+
+[devtools-2-32-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.32.0
+[devtools-2-33-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.33.0
+
+## 3.3.0
+
+### Language
+
+Dart 3.3 adds [extension types] to the language. To use them, set your
+package's [SDK constraint][language version] lower bound to 3.3 or greater
+(`sdk: '^3.3.0'`).
+
+#### Extension types
+
+[extension types]: https://github.com/dart-lang/language/issues/2727
+
+An _extension type_ wraps an existing type with a different, static-only
+interface. It works in a way which is in many ways similar to a class that
+contains a single final instance variable holding the wrapped object, but
+without the space and time overhead of an actual wrapper object.
+
+Extension types are introduced by _extension type declarations_. Each
+such declaration declares a new named type (not just a new name for the
+same type). It declares a _representation variable_ whose type is the
+_representation type_. The effect of using an extension type is that the
+_representation_ (that is, the value of the representation variable) has
+the members declared by the extension type rather than the members declared
+by its "own" type (the representation type). Example:
+
+```dart
+extension type Meters(int value) {
+  String get label => '${value}m';
+  Meters operator +(Meters other) => Meters(value + other.value);
+}
+
+void main() {
+  var m = Meters(42); // Has type `Meters`.
+  var m2 = m + m; // OK, type `Meters`.
+  // int i = m; // Compile-time error, wrong type.
+  // m.isEven; // Compile-time error, no such member.
+  assert(identical(m, m.value)); // Succeeds.
+}
+```
+
+The declaration `Meters` is an extension type that has representation type
+`int`. It introduces an implicit constructor `Meters(int value);` and a
+getter `int get value`. `m` and `m.value` is the very same object, but `m`
+has type `Meters` and `m.value` has type `int`. The point is that `m`
+has the members of `Meters` and `m.value` has the members of `int`.
+
+Extension types are entirely static, they do not exist at run time. If `o`
+is the value of an expression whose static type is an extension type `E`
+with representation type `R`, then `o` is just a normal object whose
+run-time type is a subtype of `R`, exactly like the value of an expression
+of type `R`. Also the run-time value of `E` is `R` (for example, `E == R`
+is true). In short: At run time, an extension type is erased to the
+corresponding representation type.
+
+A method call on an expression of an extension type is resolved at
+compile-time, based on the static type of the receiver, similar to how
+extension method calls work. There is no virtual or dynamic dispatch. This,
+combined with no memory overhead, means that extension types are zero-cost
+wrappers around their representation value.
+
+While there is thus no performance cost to using extension types, there is
+a safety cost. Since extension types are erased at compile time, run-time
+type tests on values that are statically typed as an extension type will
+check the type of the representation object instead, and if the type check
+looks like it tests for an extension type, like `is Meters`, it actually
+checks for the representation type, that is, it works exactly like `is int`
+at run time. Moreover, as mentioned above, if an extension type is used as
+a type argument to a generic class or function, the type variable will be
+bound to the representation type at run time. For example:
+
+```dart
+void main() {
+  var meters = Meters(3);
+
+  // At run time, `Meters` is just `int`.
+  print(meters is int); // Prints "true".
+  print(<Meters>[] is List<int>); // Prints "true".
+
+  // An explicit cast is allowed and succeeds as well:
+  List<Meters> meterList = <int>[1, 2, 3] as List<Meters>;
+  print(meterList[1].label); // Prints "2m".
+}
+```
+
+Extension types are useful when you are willing to sacrifice some run-time
+encapsulation in order to avoid the overhead of wrapping values in
+instances of wrapper classes, but still want to provide a different
+interface than the wrapped object. An example of that is interop, where you
+may have data that are not Dart objects to begin with (for example, raw
+JavaScript objects when using JavaScript interop), and you may have large
+collections of objects where it's not efficient to allocate an extra object
+for each element.
+
+#### Other changes
+
+- **Breaking Change** [#54056][]: The rules for private field promotion have
+  been changed so that an abstract getter is considered promotable if there are
+  no conflicting declarations. There are no conflicting declarations if
+  there are no non-final fields, external fields, concrete getters, or
+  `noSuchMethod` forwarding getters with the same name in the same library.
+  This makes the implementation more consistent and allows
+  type promotion in a few rare scenarios where it wasn't previously allowed.
+  It is unlikely, but this change could cause a breakage by changing
+  an inferred type in a way that breaks later code. For example:
+
+  ```dart
+  class A {
+    int? get _field;
+  }
+  class B extends A {
+    final int? _field;
+    B(this._field);
+  }
+  test(A a) {
+    if (a._field != null) {
+      var x = a._field; // Previously had type `int?`; now has type `int`
+      ...
+      x = null; // Previously allowed; now causes a compile-time error.
+    }
+  }
+  ```
+
+  Affected code can be fixed by adding an explicit type annotation.
+  For example, in the above snippet, `var x` can be changed to `int? x`.
+
+  It's also possible that some continuous integration configurations might fail
+  if they have been configured to treat warnings as errors, because the expanded
+  type promotion could lead to one of the following warnings:
+
+  - `unnecessary_non_null_assertion`
+  - `unnecessary_cast`
+  - `invalid_null_aware_operator`
+
+  These warnings can be addressed in the usual way, by removing the unnecessary
+  operation in the first two cases, or changing `?.` to `.` in the third case.
+
+  To learn more about other rules surrounding type promotion,
+  check out the guide on [Fixing type promotion failures][].
+
+[#54056]: https://github.com/dart-lang/sdk/issues/54056
+[Fixing type promotion failures]: https://dart.dev/tools/non-promotion-reasons
+
+### Libraries
+
+#### `dart:core`
+
+- `String.fromCharCodes` now allow `start` and `end` to be after the end of
+  the `Iterable` argument, just like `skip` and `take` does on an `Iterable`.
+
+#### `dart:ffi`
+
+- In addition to functions, `@Native` can now be used on fields.
+- Allow taking the address of native functions and fields via
+  `Native.addressOf`.
+- The `elementAt` pointer arithmetic extension methods on
+  core `Pointer` types are now deprecated.
+  Migrate to the new `-` and `+` operators instead.
+- The experimental and deprecated `@FfiNative` annotation has been removed.
+  Usages should be updated to use the `@Native` annotation.
+
+#### `dart:js_interop`
+
+- **Breaking Change in the representation of JS types** [#52687][]: JS types
+  like `JSAny` were previously represented using a custom erasure of
+  `@staticInterop` types that were compiler-specific. They are now represented
+  as extension types where their representation types are compiler-specific.
+  This means that user-defined `@staticInterop` types that implemented `JSAny`
+  or `JSObject` can no longer do so and need to use
+  `JSObject.fromInteropObject`. Going forward, it's recommended to use extension
+  types to define interop APIs. Those extension types can still implement JS
+  types.
+- **JSArray and JSPromise generics**: `JSArray` and `JSPromise` are now generic
+  types whose type parameter is a subtype of `JSAny?`. Conversions to and from
+  these types are changed to account for the type parameters of the Dart or JS
+  type, respectively.
+- **Breaking Change in names of extensions**: Some `dart:js_interop` extension
+  members are moved to different extensions on the same type or a supertype to
+  better organize the API surface. See `JSAnyUtilityExtension` and
+  `JSAnyOperatorExtension` for the new extensions. This shouldn't make a
+  difference unless the extension names were explicitly used.
+- Add `importModule` to allow users to dynamically import modules using the JS
+  `import()` expression.
+
+[#52687]: https://github.com/dart-lang/sdk/issues/52687
+
+#### `dart:js_interop_unsafe`
+
+- Add `has` helper to make `hasProperty` calls more concise.
+
+#### `dart:typed_data`
+
+- **BREAKING CHANGE** (https://github.com/dart-lang/sdk/issues/53218) The
+  unmodifiable view classes for typed data are deprecated. Instead of using the
+  constructors for these classes to create an unmodifiable view, e.g.
+
+  ```dart
+  Uint8List data = ...
+  final readOnlyView = UnmodifiableUint8ListView(data);
+  ```
+
+  use the new `asUnmodifiableView()` methods:
+
+  ```dart
+  Uint8List data = ...
+  final readOnlyView = data.asUnmodifiableView();
+  ```
+
+  The reason for this change is to allow more flexibility in the implementation
+  of typed data so the native and web platforms can use different strategies
+  for ensuring typed data has good performance.
+
+  The deprecated types will be removed in a future Dart version.
+
+#### `dart:nativewrappers`
+
+- **Breaking Change** [#51896][]: The NativeWrapperClasses are marked `base` so
+  that none of their subtypes can be implemented. Implementing subtypes can lead
+  to crashes when passing such native wrapper to a native call, as it will try
+  to unwrap a native field that doesn't exist.
+
+[#51896]: https://github.com/dart-lang/sdk/issues/51896
+
+### Tools
+
+#### Dart command line
+
+- The `dart create` command now uses v3 of `package:lints`,
+  including multiple new recommended lints by default.
+  To learn more about the updated collection of lints,
+  check out the `package:lints` [3.0.0 changelog entry][lints-3-0].
+
+[lints-3-0]: https://pub.dev/packages/lints/changelog#300
+
+#### DevTools
+
+- Updated DevTools to version 2.31.1 from 2.28.1.
+  To learn more, check out the release notes for versions
+  [2.29.0][devtools-2-29-0], [2.30.0][devtools-2-30-0],
+  and [2.31.0][devtools-2-31-0].
+
+[devtools-2-29-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.29.0
+[devtools-2-30-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.30.0
+[devtools-2-31-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.31.0
+
+#### Wasm compiler (dart2wasm)
+
+- **Breaking Change** [#54004][]: `dart:js_util`, `package:js`, and `dart:js`
+  are now disallowed from being imported when compiling with `dart2wasm`. Prefer
+  using `dart:js_interop` and `dart:js_interop_unsafe`.
+
+[#54004]: https://github.com/dart-lang/sdk/issues/54004
+
+#### Development JavaScript compiler (DDC)
+
+- Type arguments of `package:js` interop types are now printed as `any` instead
+  of being omitted. This is simply a change to the textual representation of
+  package js types that have type arguments. These type arguments are still
+  completely ignored by the type system at runtime.
+
+- Removed "implements <...>" text from the Chrome custom formatter display for
+  Dart classes. This information provides little value and keeping it imposes an
+  unnecessary maintenance cost.
+
+#### Production JavaScript compiler (dart2js)
+
+- **Breaking Change** [#54201][]:
+  The `Invocation` that is passed to `noSuchMethod` will no longer have a
+  minified `memberName`, even when dart2js is invoked with `--minify`.
+  See [#54201][] for more details.
+
+[#54201]: https://github.com/dart-lang/sdk/issues/54201
+
+#### Analyzer
+
+- You can now suppress diagnostics in `pubspec.yaml` files by
+  adding an `# ignore: <diagnostic_id>` comment.
+- Invalid `dart doc` comment directives are now reported.
+- The [`flutter_style_todos`][] lint now has a quick fix.
+
+[`flutter_style_todos`]: https://dart.dev/lints/flutter_style_todos
+
+#### Linter
+
+- Removed the `iterable_contains_unrelated_type` and
+  `list_remove_unrelated_type` lints.
+  Consider migrating to the expanded
+  [`collection_methods_unrelated_type`][] lint.
+- Removed various lints that are no longer necessary with sound null safety:
+  - `always_require_non_null_named_parameters`
+  - `avoid_returning_null`,
+  - `avoid_returning_null_for_future`
+
+[`collection_methods_unrelated_type`]: https://dart.dev/lints/collection_methods_unrelated_type
+
+## 3.2.3 - 2023-12-06
+
+This is a patch release that:
+
+- Disallows final fields to be used in a constant context during analysis
+  (issue [#54232][]).
+- Upgrades Dart DevTools to version 2.28.4 (issue [#54213][]).
+- Fixes new AOT snapshots in the SDK failing with SIGILL in ARM
+  environments that don't support the integer division
+  instructions or x86-64 environments that don't support
+  SSE4.1 (issue [#54215][]).
+
+[#54232]: https://github.com/dart-lang/sdk/issues/54232
+[#54213]: https://github.com/dart-lang/sdk/issues/54213
+[#54215]: https://github.com/dart-lang/sdk/issues/54215
+
+## 3.2.2 - 2023-11-29
+
+This is a patch release that:
+
+- Adjusts the nullablity computations in the implementation of the
+  upper bound algorithm in the compiler frontend (issue [#53999][]).
+
+- Fixes missing closure code completion entries for function parameters
+  for LSP-based editors like VS Code (issue [#54112][]).
+
+[#53999]: https://github.com/dart-lang/sdk/issues/53999
+[#54112]: https://github.com/dart-lang/sdk/issues/54112
+
+## 3.2.1 - 2023-11-22
+
+This is a patch release that:
+
+- Fixes the left/mobile sidebar being empty on non-class pages
+  in documentation generated with `dart doc` (issue [#54073][]).
+
+- Fixes a JSON array parsing bug that causes a segmentation fault when
+  `flutter test` is invoked with the `--coverage` flag
+  (SDK issue [#54059][], Flutter issue [#124145][]).
+
+- Upgrades Dart DevTools to version 2.28.3 (issue [#54085][]).
+
+[#54073]: https://github.com/dart-lang/sdk/issues/54073
+[#54059]: https://github.com/dart-lang/sdk/issues/54059
+[#124145]: https://github.com/flutter/flutter/issues/124145
+[#54085]: https://github.com/dart-lang/sdk/issues/54085
+
+## 3.2.0 - 2023-11-15
+
+### Language
+
+Dart 3.2 adds the following features. To use them, set your package's [SDK
+constraint][language version] lower bound to 3.2 or greater (`sdk: '^3.2.0'`).
+
+[language version]: https://dart.dev/guides/language/evolution
+
+- **Private field promotion**: In most circumstances, the types of private final
+  fields can now be promoted by null checks and `is` tests. For example:
+
+  ```dart
+  class Example {
+    final int? _privateField;
+    Example(this._privateField);
+
+    f() {
+      if (_privateField != null) {
+        // _privateField has now been promoted; you can use it without
+        // null checking it.
+        int i = _privateField; // OK
+      }
+    }
+  }
+
+  // Private field promotions also work from outside of the class:
+  f(Example x) {
+    if (x._privateField != null) {
+      int i = x._privateField; // OK
+    }
+  }
+  ```
+
+  To ensure soundness, a field is not eligible for field promotion in the
+  following circumstances:
+  - If it's not final (because a non-final field could be changed in between the
+    test and the usage, invalidating the promotion).
+  - If it's overridden elsewhere in the library by a concrete getter or a
+    non-final field (because an access to an overridden field might resolve at
+    runtime to the overriding getter or field).
+  - If it's not private (because a non-private field might be overridden
+    elsewhere in the program).
+  - If it has the same name as a concrete getter or a non-final field in some
+    other unrelated class in the library (because a class elsewhere in the
+    program might extend one of the classes and implement the other, creating an
+    override relationship between them).
+  - If there is a concrete class `C` in the library whose interface contains a
+    getter with the same name, but `C` does not have an implementation of that
+    getter (such unimplemented getters aren't safe for field promotion, because
+    they are implicitly forwarded to `noSuchMethod`, which might not return the
+    same value each time it's called).
+
+- **Breaking Change** [#53167][]: Use a more precise split point for refutable
+  patterns. Previously, in an if-case statement, if flow analysis could prove
+  that the scrutinee expression was guaranteed to throw an exception, it would
+  sometimes fail to propagate type promotions implied by the pattern to the
+  (dead) code that follows. This change makes the type promotion behavior of
+  if-case statements consistent regardless of whether the scrutinee expression
+  throws an exception.
+
+  No live code is affected by this change, but there is a small chance that the
+  change in types will cause a compile-time error to appear in some dead code in
+  the user's project, where no compile-time error appeared previously.
+
+[#53167]: https://github.com/dart-lang/sdk/issues/53167
+
+### Libraries
+
+#### `dart:async`
+
+- Added `broadcast` parameter to `Stream.empty` constructor.
+
+#### `dart:cli`
+
+- **Breaking change** [#52121][]:
+  - `waitFor` is disabled by default and slated for removal in 3.4. Attempting
+  to call this function will now throw an exception. Users that still depend
+  on `waitFor` can enable it by passing `--enable_deprecated_wait_for` flag
+  to the VM.
+
+[#52121]: https://github.com/dart-lang/sdk/issues/52121
+
+#### `dart:convert`
+
+- **Breaking change** [#52801][]:
+  - Changed return types of `utf8.encode()` and `Utf8Codec.encode()` from
+    `List<int>` to `Uint8List`.
+
+[#52801]: https://github.com/dart-lang/sdk/issues/52801
+
+#### `dart:developer`
+
+- Deprecated the `Service.getIsolateID` method.
+- Added `getIsolateId` method to `Service`.
+- Added `getObjectId` method to `Service`.
+
+#### `dart:ffi`
+
+- Added the `NativeCallable.isolateLocal` constructor. This creates
+  `NativeCallable`s with the same functionality as `Pointer.fromFunction`,
+  except that `NativeCallable` accepts closures.
+- Added the `NativeCallable.keepIsolateAlive` method, which determines whether
+  the `NativeCallable` keeps the isolate that created it alive.
+- All `NativeCallable` constructors can now accept closures. Previously
+  `NativeCallable`s had the same restrictions as `Pointer.fromFunction`, and
+  could only create callbacks for static functions.
+- **Breaking change** [#53311][]: `NativeCallable.nativeFunction` now throws an
+  error if is called after the `NativeCallable` has already been `close`d. Calls
+  to `close` after the first are now ignored.
+
+[#53311]: https://github.com/dart-lang/sdk/issues/53311
+
+#### `dart:io`
+
+- **Breaking change** [#53005][]: The headers returned by
+  `HttpClientResponse.headers` and `HttpRequest.headers` no longer include
+  trailing whitespace in their values.
+
+- **Breaking change** [#53227][]: Folded headers values returned by
+  `HttpClientResponse.headers` and `HttpRequest.headers` now have a space
+  inserted at the fold point.
+
+[#53005]: https://dartbug.com/53005
+[#53227]: https://dartbug.com/53227
+
+#### `dart:isolate`
+
+- Added `Isolate.packageConfigSync` and `Isolate.resolvePackageUriSync` APIs.
+
+#### `dart:js_interop`
+
+- **Breaking Change on JSNumber.toDart and Object.toJS**:
+  `JSNumber.toDart` is removed in favor of `toDartDouble` and `toDartInt` to
+  make the type explicit. `Object.toJS` is also removed in favor of
+  `Object.toJSBox`. Previously, this function would allow Dart objects to flow
+  into JS unwrapped on the JS backends. Now, there's an explicit wrapper that is
+  added and unwrapped via `JSBoxedDartObject.toDart`. Similarly,
+  `JSExportedDartObject` is renamed to `JSBoxedDartObject` and the extensions
+  `ObjectToJSExportedDartObject` and `JSExportedDartObjectToObject` are renamed
+  to `ObjectToJSBoxedDartObject` and `JSBoxedDartObjectToObject` in order to
+  avoid confusion with `@JSExport`.
+- **Type parameters in external APIs**:
+  Type parameters must now be bound to a static interop type or one of the
+  `dart:js_interop` types like `JSNumber` when used in an external API. This
+  only affects `dart:js_interop` classes and not `package:js` or other forms of
+  JS interop.
+- **Subtyping `dart:js_interop` types**:
+  `@staticInterop` types can subtype only `JSObject` and `JSAny` from the set of
+  JS types in `dart:js_interop`. Subtyping other types from `dart:js_interop`
+  would result in confusing type errors before, so this makes it a static error.
+- **Global context of `dart:js_interop` and `@staticInterop` APIs**:
+  Static interop APIs will now use the same global context as non-static interop
+  instead of `globalThis` to avoid a greater migration. Static interop APIs,
+  either through `dart:js_interop` or the `@staticInterop` annotation, have used
+  JavaScript's `globalThis` as the global context. This is relevant to things
+  like external top-level members or external constructors, as this is the root
+  context we expect those members to reside in. Historically, this was not the
+  case in dart2js and DDC. We used either `self` or DDC's `global` in non-static
+  interop APIs with `package:js`. So, static interop APIs will now use one of
+  those global contexts. Functionally, this should matter in only a very small
+  number of cases, like when using older browser versions. `dart:js_interop`'s
+  `globalJSObject` is also renamed to `globalContext` and returns the global
+  context used in the lowerings.
+- **Breaking Change on Types of `dart:js_interop` External APIs**:
+  External JS interop APIs when using `dart:js_interop` are restricted to a set
+  of allowed types. Namely, this includes the primitive types like `String`, JS
+  types from `dart:js_interop`, and other static interop types (either through
+  `@staticInterop` or extension types).
+- **Breaking Change on `dart:js_interop` `isNull` and `isUndefined`**:
+  `null` and `undefined` can only be discerned in the JS backends. dart2wasm
+  conflates the two values and treats them both as Dart null. Therefore, these
+  two helper methods should not be used on dart2wasm and will throw to avoid
+  potentially erroneous code.
+- **Breaking Change on `dart:js_interop` `typeofEquals` and `instanceof`**:
+  Both APIs now return a `bool` instead of a `JSBoolean`. `typeofEquals` also
+  now takes in a `String` instead of a `JSString`.
+- **Breaking Change on `dart:js_interop` `JSAny` and `JSObject`**:
+  These types can only be implemented, and no longer extended, by user
+  `@staticInterop` types.
+- **Breaking Change on `dart:js_interop` `JSArray.withLength`**:
+  This API now takes in an `int` instead of `JSNumber`.
+
+### Tools
+
+#### Development JavaScript compiler (DDC)
+
+- Applications compiled by DDC will no longer add members to the native
+  JavaScript Object prototype.
+- **Breaking change for JS interop with Symbols and BigInts**:
+  JavaScript `Symbol`s and `BigInt`s are now associated with their own
+  interceptor and should not be used with `package:js` classes. These types were
+  being intercepted with the assumption that they are a subtype of JavaScript's
+  `Object`, but this is incorrect. This lead to erroneous behavior when using
+  these types as Dart `Object`s. See [#53106][] for more details. Use
+  `dart:js_interop`'s `JSSymbol` and `JSBigInt` with extension types to interop
+  with these types.
+
+#### Production JavaScript compiler (dart2js)
+
+- **Breaking change for JS interop with Symbols and BigInts**:
+  JavaScript `Symbol`s and `BigInt`s are now associated with their own
+  interceptor and should not be used with `package:js` classes. These types were
+  being intercepted with the assumption that they are a subtype of JavaScript's
+  `Object`, but this is incorrect. This lead to erroneous behavior when using
+  these types as Dart `Object`s. See [#53106][] for more details. Use
+  `dart:js_interop`'s `JSSymbol` and `JSBigInt` with extension types to interop
+  with these types.
+
+[#53106]: https://github.com/dart-lang/sdk/issues/53106
+
+#### Dart command line
+
+- The `dart create` command has a new `cli` template
+  to quickly create Dart command-line applications
+  with basic argument parsing capabilities.
+  To learn more about using the template,
+  run `dart help create`.
+
+#### Dart format
+
+- Always split enum declarations containing a line comment.
+- Fix regression in splitting type annotations with library prefixes.
+- Support `--enable-experiment` command-line option to enable language
+  experiments.
+
+#### DevTools
+
+- Incorporated the [2.26.1][devtools-2-26-1], [2.27.0][devtools-2-27-0], and
+  [2.28.1][devtools-2-28-1] releases of DevTools.
+
+[devtools-2-26-1]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.26.1
+[devtools-2-27-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.27.0
+[devtools-2-28-1]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.28.1
+
+#### Linter
+
+- Added the experimental [`annotate_redeclares`][] lint.
+- Marked the [`use_build_context_synchronously`][] lint as stable.
+
+[`annotate_redeclares`]: https://dart.dev/lints/annotate_redeclares
+[`use_build_context_synchronously`]: https://dart.dev/lints/use_build_context_synchronously
+
+#### Pub
+
+- New option `dart pub upgrade --tighten` which will update dependencies' lower
+  bounds in `pubspec.yaml` to match the current version.
+- The commands `dart pub get`/`add`/`upgrade` will now show if a dependency
+  changed between direct, dev and transitive dependency.
+- The command `dart pub upgrade` no longer shows unchanged dependencies.
+
+## 3.1.5 - 2023-10-25
+
+This is a patch release that:
+
+- Fixes an issue affecting Dart compiled to JavaScript running in Node.js 21. A
+  change in Node.js 21 affected the Dart Web compiler runtime. This patch
+  release accommodates for those changes (issue #53810).
+
+[#53810]: https://github.com/dart-lang/sdk/issues/53810
+
+## 3.1.4 - 2023-10-18
+
+This is a patch release that:
+
+- Fixes an issue in the Dart VM, users are not being able to see
+  value of variables while debugging code (issue [#53747]).
+
+[#53654]: https://github.com/dart-lang/sdk/issues/53747
+
+## 3.1.3 - 2023-09-27
+
+This is a patch release that:
+
+- Fixes a bug in dart2js which would cause the compiler to crash when using
+  `@staticInterop` `@anonymous` factory constructors with type parameters (see
+  issue [#53579] for more details).
+
+- The standalone Dart VM now exports symbols only for the Dart_* embedding API
+  functions, avoiding conflicts with other DSOs loaded into the same process,
+  such as shared libraries loaded through `dart:ffi`, that may have different
+  versions of the same symbols (issue [#53503]).
+
+- Fixes an issue with super slow access to variables while debugging.
+  The fix avoids searching static functions in the imported libraries
+  as references to members are fully resolved by the front-end. (issue
+  [#53541])
+
+[#53579]: https://github.com/dart-lang/sdk/issues/53579
+[#53267]: https://github.com/dart-lang/sdk/issues/53503
+[#53541]: https://github.com/dart-lang/sdk/issues/53541
+
+## 3.1.2 - 2023-09-13
+
+This is a patch release that:
+
+- Fixes a bug in dart2js which crashed the compiler when a typed record pattern
+  was used outside the scope of a function body, such as in a field initializer.
+  For example `final x = { for (var (int a,) in someList) a: a };`
+  (issue [#53449])
+
+- Fixes an expedient issue of users seeing an unhandled
+  exception pause in the debugger, please see
+  https://github.com/dart-lang/sdk/issues/53450 for more
+  details.
+  The fix uses try/catch in lookupAddresses instead of
+  Future error so that we don't see an unhandled exception
+  pause in the debugger (issue [#53450])
+
+[#53449]: https://github.com/dart-lang/sdk/issues/53449
+[#53450]: https://github.com/dart-lang/sdk/issues/53450
+
+## 3.1.1 - 2023-09-07
+
+This is a patch release that:
+
+- Fixes a bug in the parser which prevented a record pattern from containing a
+  nested record pattern, where the nested record pattern uses record
+  destructuring shorthand syntax, for example `final ((:a, :b), c) = record;`
+  (issue [#53352]).
+
+[#53352]: https://github.com/dart-lang/sdk/issues/53352
+
+## 3.1.0 - 2023-08-16
+
+### Libraries
+
+#### `dart:async`
+
+- **Breaking change** [#52334][]:
+  - Added the `interface` modifier to purely abstract classes:
+    `MultiStreamController`, `StreamConsumer`, `StreamIterator` and
+    `StreamTransformer`. As a result, these types can only be implemented,
+    not extended or mixed in.
+
+[#52334]: https://github.com/dart-lang/sdk/issues/52334
+
+#### `dart:core`
+
+- `Uri.base` on native platforms now respects `IOOverrides` overriding
+   current directory ([#39796][]).
+
+[#39796]: https://github.com/dart-lang/sdk/issues/39796
+
+#### `dart:ffi`
+
+- Added the `NativeCallable` class, which can be used to create callbacks that
+  allow native code to call into Dart code from any thread. See
+  `NativeCallable.listener`. In future releases, `NativeCallable` will be
+  updated with more functionality, and will become the recommended way of
+  creating native callbacks for all use cases, replacing `Pointer.fromFunction`.
+
+#### `dart:io`
+
+- **Breaking change** [#51486][]:
+  - Added `sameSite` to the `Cookie` class.
+  - Added class `SameSite`.
+- **Breaking change** [#52027][]: `FileSystemEvent` is
+  [`sealed`](https://dart.dev/language/class-modifiers#sealed). This means
+  that `FileSystemEvent` cannot be extended or implemented.
+- Added a deprecation warning when `Platform` is instantiated.
+- Added `Platform.lineTerminator` which exposes the character or characters
+  that the operating system uses to separate lines of text, e.g.,
+  `"\r\n"` on Windows.
+
+[#51486]: https://github.com/dart-lang/sdk/issues/51486
+[#52027]: https://github.com/dart-lang/sdk/issues/52027
+
+#### `dart:js_interop`
+
+- **Object literal constructors**:
+  `ObjectLiteral` is removed from `dart:js_interop`. It's no longer needed in
+  order to declare an object literal constructor with inline classes. As long as
+  an external constructor has at least one named parameter, it'll be treated as
+  an object literal constructor. If you want to create an object literal with no
+  named members, use `{}.jsify()`.
+
+### Other libraries
+
+#### `package:js`
+
+- **Breaking change to `@staticInterop` and `external` extension members**:
+  `external` `@staticInterop` members and `external` extension members can no
+  longer be used as tear-offs. Declare a closure or a non-`external` method that
+  calls these members, and use that instead.
+- **Breaking change to `@staticInterop` and `external` extension members**:
+  `external` `@staticInterop` members and `external` extension members will
+  generate slightly different JS code for methods that have optional parameters.
+  Whereas before, the JS code passed in the default value for missing optionals,
+  it will now pass in only the provided members. This aligns with how JS
+  parameters work, where omitted parameters are actually omitted. For example,
+  calling `external void foo([int a, int b])` as `foo(0)` will now result in
+  `foo(0)`, and not `foo(0, null)`.
+
+### Tools
+
+#### DevTools
+
+- Incorporated the [2.24.0][devtools-2-24-0] and [2.25.0][devtools-2-25-0]
+  releases of DevTools.
+
+[devtools-2-24-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.24.0
+[devtools-2-25-0]: https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.25.0
+
+#### Linter
+
+- Added new static analysis lints you can [enable][enable-lints] in
+  your package's `analysis_options.yaml` file:
+  - [`no_self_assignments`](https://dart.dev/lints/no_self_assignments)
+  - [`no_wildcard_variable_uses`](https://dart.dev/lints/no_wildcard_variable_uses)
+
+[enable-lints]: https://dart.dev/tools/analysis#enabling-linter-rules
+
+## 3.0.7 - 2023-07-26
+
+This is a patch release that:
+
+- Fixes a bug in dart2js which would cause certain uses of records to lead to
+  bad codegen causing a `TypeError` or `NoSuchMethodError` to be thrown
+  at runtime (issue [#53001]).
+
+[#53001]: https://github.com/dart-lang/sdk/issues/53001
+
+## 3.0.6 - 2023-07-12
+
+This is a patch release that:
+
+- Fixes a flow in flow analysis that causes it to sometimes ignore destructuring
+  assignments (issue [#52767]).
+- Fixes an infinite loop in some web development compiles that include `is` or
+  `as` expressions involving record types with named fields (issue [#52869]).
+- Fixes a memory leak in Dart analyzer's file-watching (issue [#52791]).
+- Fixes a memory leak of file system watcher related data structures (issue [#52793]).
+
+[#52767]: https://github.com/dart-lang/sdk/issues/52767
+[#52869]: https://github.com/dart-lang/sdk/issues/52869
+[#52791]: https://github.com/dart-lang/sdk/issues/52791
+[#52793]: https://github.com/dart-lang/sdk/issues/52793
+
+## 3.0.5 - 2023-06-14
+
+This is a patch release that:
+
+- Fixes a bad cast in the frontend which can manifest as a crash in the dart2js
+  `ListFactorySpecializer` during Flutter web builds (issue [#52403]).
+
+[#52403]: https://github.com/dart-lang/sdk/issues/52403
+
+## 3.0.4 - 2023-06-07
+
+This is a patch release that:
+
+- `dart format` now handles formatting nullable record types
+  with no fields (dart_style issue [#1224]).
+- Fixes error when using records when targeting the web in development mode
+  (issue [#52480]).
+
+[#1224]: https://github.com/dart-lang/dart_style/issues/1224
+[#52480]: https://github.com/dart-lang/sdk/issues/52480
+
+## 3.0.3 - 2023-02-07
+
+This is a patch release that:
+
+- Fixes an AOT compiler crash when generating an implicit getter
+  returning an unboxed record (issue [#52449]).
+- Fixes a situation in which variables appearing in multiple branches of an
+  or-pattern might be erroneously reported as being mismatched (issue [#52373]).
+- Adds missing `interface` modifiers on the purely abstract classes
+  `MultiStreamController`, `StreamConsumer`, `StreamIterator` and
+  `StreamTransformer` (issue [#52334]).
+- Fixes an error during debugging when `InternetAddress.tryParse` is
+  used (issue [#52423]).
+- Fixes a VM issue causing crashes on hot reload (issue [#126884]).
+- Improves linter support (issue [#4195]).
+- Fixes an issue in variable patterns preventing users from expressing
+  a pattern match using a variable or wildcard pattern with a nullable
+  record type (issue [#52439]).
+- Updates warnings and provide instructions for updating the Dart pub
+  cache on Windows (issue [#52386]).
+
+[#52373]: https://github.com/dart-lang/sdk/issues/52373
+[#52334]: https://github.com/dart-lang/sdk/issues/52334
+[#52423]: https://github.com/dart-lang/sdk/issues/52423
+[#126884]: https://github.com/flutter/flutter/issues/126884
+[#4195]: https://github.com/dart-lang/linter/issues/4195
+[#52439]: https://github.com/dart-lang/sdk/issues/52439
+[#52449]: https://github.com/dart-lang/sdk/issues/52449
+[#52386]: https://github.com/dart-lang/sdk/issues/52386
+
+## 3.0.2 - 2023-05-24
+
+This is a patch release that:
+
+- Fixes a dart2js crash when using a switch case expression on a record where
+  the fields don't match the cases (issue [#52438]).
+- Add class modifier chips on class and mixin pages
+  generated with `dart doc` (issue [#3392]).
+- Fixes a situation causing the parser to fail resulting in an infinite loop
+  leading to higher memory usage (issue [#52352]).
+- Add clear errors when mixing inheritance in pre and post Dart 3 libraries
+  (issue: [#52078]).
+
+[#52438]: https://github.com/dart-lang/sdk/issues/52438
+[#3392]: https://github.com/dart-lang/dartdoc/issues/3392
+[#52352]: https://github.com/dart-lang/sdk/issues/52352
+[#52078]: https://github.com/dart-lang/sdk/issues/52078
+
+## 3.0.1 - 2023-05-17
+
+This is a patch release that:
+
+- Fixes a compiler crash involving redirecting factories and FFI
+  (issue [#124369]).
+- Fixes a dart2js crash when using a combination of local functions, generics,
+  and records (issue [#51899]).
+- Fixes incorrect error using a `void` in a switch case expression
+  (issue [#52191]).
+- Fixes a false error when using in switch case expressions when the switch
+  refers to a private getter (issue [#52041]).
+- Prevent the use of `when` and `as` as variable names in patterns
+  (issue [#52260]).
+- Fixes an inconsistency in type promotion between the analyzer and VM
+  (issue [#52241]).
+- Improve performance on functions with many parameters (issue [#1212]).
+
+[#124369]: https://github.com/flutter/flutter/issues/124369
+[#51899]: https://github.com/dart-lang/sdk/issues/51899
+[#52191]: https://github.com/dart-lang/sdk/issues/52191
+[#52041]: https://github.com/dart-lang/sdk/issues/52041
+[#52260]: https://github.com/dart-lang/sdk/issues/52260
+[#52241]: https://github.com/dart-lang/sdk/issues/52241
+[#1212]: https://github.com/dart-lang/dart_style/issues/1212
+
+## 3.0.0 - 2023-05-10
+
+### Language
+
+Dart 3.0 adds the following features. To use them, set your package's [SDK
+constraint][language version] lower bound to 3.0 or greater (`sdk: '^3.0.0'`).
+
+[language version]: https://dart.dev/guides/language/evolution
+
+- **[Records]**: Records are anonymous immutable data structures that let you
+  aggregate multiple values together, similar to [tuples][] in other languages.
+  With records, you can return multiple values from a function, create composite
+  map keys, or use them any other place where you want to bundle a couple of
+  objects together.
+
+  For example, using a record to return two values:
+
+  ```dart
+  (double x, double y) geoLocation(String name) {
+    if (name == 'Nairobi') {
+      return (-1.2921, 36.8219);
+    } else {
+      ...
+    }
+  }
+  ```
+
+- **[Pattern matching]**: Expressions build values out of smaller pieces.
+  Conversely, patterns are an expressive tool for decomposing values back into
+  their constituent parts. Patterns can call getters on an object, access
+  elements from a list, pull fields out of a record, etc. For example, we can
+  destructure the record from the previous example like so:
+
+  ```dart
+  var (lat, long) = geoLocation('Nairobi');
+  print('Nairobi is at $lat, $long.');
+  ```
+
+  Patterns can also be used in [switch cases]. There, you can destructure values
+  and also test them to see if they have a certain type or value:
+
+  ```dart
+  switch (object) {
+    case [int a]:
+      print('A list with a single integer element $a');
+    case ('name', _):
+      print('A two-element record whose first field is "name".');
+    default: print('Some other object.');
+  }
+  ```
+
+  Also, as you can see, non-empty switch cases no longer need `break;`
+  statements.
+
+  **Breaking change**: Dart 3.0 interprets [switch cases] as patterns instead of
+  constant expressions. Most constant expressions found in switch cases are
+  valid patterns with the same meaning (named constants, literals, etc.). You
+  may need to tweak a few constant expressions to make them valid. This only
+  affects libraries that have upgraded to language version 3.0.
+
+- **[Switch expressions]**: Switch expressions allow you to use patterns and
+  multi-way branching in contexts where a statement isn't allowed:
+
+  ```dart
+  return TextButton(
+    onPressed: _goPrevious,
+    child: Text(switch (page) {
+      0 => 'Exit story',
+      1 => 'First page',
+      _ when page == _lastPage => 'Start over',
+      _ => 'Previous page',
+    }),
+  );
+  ```
+
+- **[If-case statements and elements]**: A new if construct that matches a value
+  against a pattern and executes the then or else branch depending on whether
+  the pattern matches:
+
+  ```dart
+  if (json case ['user', var name]) {
+    print('Got user message for user $name.');
+  }
+  ```
+
+  There is also a corresponding [if-case element] that can be used in collection
+  literals.
+
+- **[Sealed classes]**: When you mark a type `sealed`, the compiler ensures that
+  switches on values of that type [exhaustively cover] every subtype. This
+  enables you to program in an [algebraic datatype][] style with the
+  compile-time safety you expect:
+
+  ```dart
+  sealed class Amigo {}
+  class Lucky extends Amigo {}
+  class Dusty extends Amigo {}
+  class Ned extends Amigo {}
+
+  String lastName(Amigo amigo) =>
+      switch (amigo) {
+        Lucky _ => 'Day',
+        Ned _   => 'Nederlander',
+      };
+  ```
+
+  In this last example, the compiler reports an error that the switch doesn't
+  cover the subclass `Dusty`.
+
+- **[Class modifiers]**: New modifiers `final`, `interface`, `base`, and `mixin`
+  on `class` and `mixin` declarations let you control how the type can be used.
+  By default, Dart is flexible in that a single class declaration can be used as
+  an interface, a superclass, or even a mixin. This flexibility can make it
+  harder to evolve an API over time without breaking users. We mostly keep the
+  current flexible defaults, but these new modifiers give you finer-grained
+  control over how the type can be used.
+
+  **Breaking change:** Class declarations from libraries that have been upgraded
+  to Dart 3.0 can no longer be used as mixins by default. If you want the class
+  to be usable as both a class and a mixin, mark it [`mixin class`][mixin
+  class]. If you want it to be used only as a mixin, make it a `mixin`
+  declaration. If you haven't upgraded a class to Dart 3.0, you can still use it
+  as a mixin.
+
+- **Breaking change** [#50902][]: Dart reports a compile-time error if a
+  `continue` statement targets a [label] that is not a loop (`for`, `do` and
+  `while` statements) or a `switch` member. Fix this by changing the `continue`
+  to target a valid labeled statement.
+
+- **Breaking change** [language/#2357][]: Starting in language version 3.0,
+  Dart reports a compile-time error if a colon (`:`) is used as the
+  separator before the default value of an optional named parameter.
+  Fix this by changing the colon (`:`) to an equal sign (`=`).
+
+[records]: https://dart.dev/language/records
+[tuples]: https://en.wikipedia.org/wiki/Tuple
+[pattern matching]: https://dart.dev/language/patterns
+[switch cases]: https://dart.dev/language/branches#switch
+[switch expressions]: https://dart.dev/language/branches#switch-expressions
+[if-case statements and elements]: https://dart.dev/language/branches#if-case
+[if-case element]: https://dart.dev/language/collections#control-flow-operators
+[sealed classes]: https://dart.dev/language/class-modifiers#sealed
+[exhaustively cover]: https://dart.dev/language/branches#exhaustiveness-checking
+[algebraic datatype]: https://en.wikipedia.org/wiki/Algebraic_data_type
+[class modifiers]: https://dart.dev/language/class-modifiers
+[mixin class]: https://dart.dev/language/mixins#class-mixin-or-mixin-class
+[#50902]: https://github.com/dart-lang/sdk/issues/50902
+[label]: https://dart.dev/language/branches#switch
+[language/#2357]: https://github.com/dart-lang/language/issues/2357
+
+### Libraries
+
+#### General changes
+
+- **Breaking Change**: Non-`mixin` classes in the platform libraries
+  can no longer be mixed in, unless they are explicitly marked as `mixin class`.
+  The following existing classes have been made mixin classes:
+  * `Iterable`
+  * `IterableMixin` (now alias for `Iterable`)
+  * `IterableBase` (now alias for `Iterable`)
+  * `ListMixin`
+  * `SetMixin`
+  * `MapMixin`
+  * `LinkedListEntry`
+  * `StringConversionSink`
+
+#### `dart:core`
+- Added `bool.parse` and `bool.tryParse` static methods.
+- Added `DateTime.timestamp()` constructor to get current time as UTC.
+- The type of `RegExpMatch.pattern` is now `RegExp`, not just `Pattern`.
+
+- **Breaking change** [#49529][]:
+  - Removed the deprecated `List` constructor, as it wasn't null safe.
+    Use list literals (e.g. `[]` for an empty list or `<int>[]` for an empty
+    typed list) or [`List.filled`][].
+  - Removed the deprecated `onError` argument on [`int.parse`][], [`double.parse`][],
+    and [`num.parse`][]. Use the [`tryParse`][] method instead.
+  - Removed the deprecated [`proxy`][] and [`Provisional`][] annotations.
+    The original `proxy` annotation has no effect in Dart 2,
+    and the `Provisional` type and [`provisional`][] constant
+    were only used internally during the Dart 2.0 development process.
+  - Removed the deprecated [`Deprecated.expires`][] getter.
+    Use [`Deprecated.message`][] instead.
+  - Removed the deprecated [`CastError`][] error.
+    Use [`TypeError`][] instead.
+  - Removed the deprecated [`FallThroughError`][] error. The kind of
+    fall-through previously throwing this error was made a compile-time
+    error in Dart 2.0.
+  - Removed the deprecated [`NullThrownError`][] error. This error is never
+    thrown from null safe code.
+  - Removed the deprecated [`AbstractClassInstantiationError`][] error. It was made
+    a compile-time error to call the constructor of an abstract class in Dart 2.0.
+  - Removed the deprecated [`CyclicInitializationError`]. Cyclic dependencies are
+    no longer detected at runtime in null safe code. Such code will fail in other
+    ways instead, possibly with a StackOverflowError.
+  - Removed the deprecated [`NoSuchMethodError`][] default constructor.
+    Use the [`NoSuchMethodError.withInvocation`][] named constructor instead.
+  - Removed the deprecated [`BidirectionalIterator`][] class.
+    Existing bidirectional iterators can still work, they just don't have
+    a shared supertype locking them to a specific name for moving backwards.
+
+- **Breaking change when migrating code to Dart 3.0**:
+  Some changes to platform libraries only affect code when that code is migrated
+  to language version 3.0.
+  - The `Function` type can no longer be implemented, extended or mixed in.
+    Since Dart 2.0 writing `implements Function` has been allowed
+    for backwards compatibility, but it has not had any effect.
+    In Dart 3.0, the `Function` type is `final` and cannot be subtyped,
+    preventing code from mistakenly assuming it works.
+  - The following declarations can only be implemented, not extended:
+    * `Comparable`
+    * `Exception`
+    * `Iterator`
+    * `Pattern`
+    * `Match`
+    * `RegExp`
+    * `RegExpMatch`
+    * `StackTrace`
+    * `StringSink`
+
+    None of these declarations contained any implementation to inherit,
+    and are marked as `interface` to signify that they are only intended
+    as interfaces.
+  - The following declarations can no longer be implemented or extended:
+    * `MapEntry`
+    * `OutOfMemoryError`
+    * `StackOverflowError`
+    * `Expando`
+    * `WeakReference`
+    * `Finalizer`
+
+    The `MapEntry` value class is restricted to enable later optimizations.
+    The remaining classes are tightly coupled to the platform and not
+    intended to be subclassed or implemented.
+
+[#49529]: https://github.com/dart-lang/sdk/issues/49529
+[`List.filled`]: https://api.dart.dev/stable/2.18.6/dart-core/List/List.filled.html
+[`int.parse`]: https://api.dart.dev/stable/2.18.4/dart-core/int/parse.html
+[`double.parse`]: https://api.dart.dev/stable/2.18.4/dart-core/double/parse.html
+[`num.parse`]: https://api.dart.dev/stable/2.18.4/dart-core/num/parse.html
+[`tryParse`]: https://api.dart.dev/stable/2.18.4/dart-core/num/tryParse.html
+[`Deprecated.expires`]: https://api.dart.dev/stable/2.18.4/dart-core/Deprecated/expires.html
+[`Deprecated.message`]: https://api.dart.dev/stable/2.18.4/dart-core/Deprecated/message.html
+[`AbstractClassInstantiationError`]: https://api.dart.dev/stable/2.17.4/dart-core/AbstractClassInstantiationError-class.html
+[`CastError`]: https://api.dart.dev/stable/2.17.4/dart-core/CastError-class.html
+[`FallThroughError`]: https://api.dart.dev/stable/2.17.4/dart-core/FallThroughError-class.html
+[`NoSuchMethodError`]: https://api.dart.dev/stable/2.18.4/dart-core/NoSuchMethodError/NoSuchMethodError.html
+[`NoSuchMethodError.withInvocation`]: https://api.dart.dev/stable/2.18.4/dart-core/NoSuchMethodError/NoSuchMethodError.withInvocation.html
+[`CyclicInitializationError`]: https://api.dart.dev/dev/2.19.0-430.0.dev/dart-core/CyclicInitializationError-class.html
+[`Provisional`]: https://api.dart.dev/stable/2.18.4/dart-core/Provisional-class.html
+[`provisional`]: https://api.dart.dev/stable/2.18.4/dart-core/provisional-constant.html
+[`proxy`]: https://api.dart.dev/stable/2.18.4/dart-core/proxy-constant.html
+[`CastError`]: https://api.dart.dev/stable/2.18.3/dart-core/CastError-class.html
+[`TypeError`]: https://api.dart.dev/stable/2.18.3/dart-core/TypeError-class.html
+[`FallThroughError`]: https://api.dart.dev/dev/2.19.0-374.0.dev/dart-core/FallThroughError-class.html
+[`NullThrownError`]: https://api.dart.dev/dev/2.19.0-430.0.dev/dart-core/NullThrownError-class.html
+[`AbstractClassInstantiationError`]: https://api.dart.dev/stable/2.18.3/dart-core/AbstractClassInstantiationError-class.html
+[`CyclicInitializationError`]: https://api.dart.dev/dev/2.19.0-430.0.dev/dart-core/CyclicInitializationError-class.html
+[`BidirectionalIterator`]: https://api.dart.dev/dev/2.19.0-430.0.dev/dart-core/BidirectionalIterator-class.html
+
+#### `dart:async`
+
+- Added extension member `wait` on iterables and 2-9 tuples of futures.
+
+- **Breaking change** [#49529][]:
+  - Removed the deprecated [`DeferredLibrary`][] class.
+    Use the [`deferred as`][] import syntax instead.
+
+[#49529]: https://github.com/dart-lang/sdk/issues/49529
+[`DeferredLibrary`]: https://api.dart.dev/stable/2.18.4/dart-async/DeferredLibrary-class.html
+[`deferred as`]: https://dart.dev/language/libraries#deferred-loading
+
+#### `dart:collection`
+
+- Added extension members `nonNulls`, `firstOrNull`, `lastOrNull`,
+  `singleOrNull`, `elementAtOrNull` and `indexed` on `Iterable`s.
+  Also exported from `dart:core`.
+- Deprecated the `HasNextIterator` class ([#50883][]).
+
+- **Breaking change when migrating code to Dart 3.0**:
+  Some changes to platform libraries only affect code when it is migrated
+  to language version 3.0.
+  - The following interface can no longer be extended, only implemented:
+    * `Queue`
+  - The following implementation classes can no longer be implemented:
+    * `LinkedList`
+    * `LinkedListEntry`
+  - The following implementation classes can no longer be implemented
+    or extended:
+    * `HasNextIterator` (Also deprecated.)
+    * `HashMap`
+    * `LinkedHashMap`
+    * `HashSet`
+    * `LinkedHashSet`
+    * `DoubleLinkedQueue`
+    * `ListQueue`
+    * `SplayTreeMap`
+    * `SplayTreeSet`
+
+[#50883]: https://github.com/dart-lang/sdk/issues/50883
+
+#### `dart:developer`
+
+- **Breaking change** [#49529][]:
+  - Removed the deprecated [`MAX_USER_TAGS`][] constant.
+    Use [`maxUserTags`][] instead.
+- Callbacks passed to `registerExtension` will be run in the zone from which
+  they are registered.
+
+- **Breaking change** [#50231][]:
+  - Removed the deprecated [`Metrics`][], [`Metric`][], [`Counter`][],
+    and [`Gauge`][] classes as they have been broken since Dart 2.0.
+
+[#49529]: https://github.com/dart-lang/sdk/issues/49529
+[#50231]: https://github.com/dart-lang/sdk/issues/50231
+[`MAX_USER_TAGS`]: https://api.dart.dev/stable/2.19.6/dart-developer/UserTag/MAX_USER_TAGS-constant.html
+[`maxUserTags`]: https://api.dart.dev/beta/2.19.0-255.2.beta/dart-developer/UserTag/maxUserTags-constant.html
+[`Metrics`]: https://api.dart.dev/stable/2.18.2/dart-developer/Metrics-class.html
+[`Metric`]: https://api.dart.dev/stable/2.18.2/dart-developer/Metric-class.html
+[`Counter`]: https://api.dart.dev/stable/2.18.2/dart-developer/Counter-class.html
+[`Gauge`]: https://api.dart.dev/stable/2.18.2/dart-developer/Gauge-class.html
+
+#### `dart:ffi`
+
+- The experimental `@FfiNative` annotation is now deprecated.
+  Usages should be replaced with the new `@Native` annotation.
+
+#### `dart:html`
+
+- **Breaking change**: As previously announced, the deprecated `registerElement`
+  and `registerElement2` methods in `Document` and `HtmlDocument` have been
+  removed.  See [#49536](https://github.com/dart-lang/sdk/issues/49536) for
+  details.
+
+#### `dart:math`
+
+- **Breaking change when migrating code to Dart 3.0**:
+  Some changes to platform libraries only affect code when it is migrated
+  to language version 3.0.
+  - The `Random` interface can only be implemented, not extended.
+
+#### `dart:io`
+
+- Added `name` and `signalNumber` to the `ProcessSignal` class.
+- Deprecate `NetworkInterface.listSupported`. Has always returned true since
+  Dart 2.3.
+- Finalize `httpEnableTimelineLogging` parameter name transition from `enable`
+  to `enabled`. See [#43638][].
+- Favor IPv4 connections over IPv6 when connecting sockets. See
+  [#50868].
+- **Breaking change** [#51035][]:
+  - Update `NetworkProfiling` to accommodate new `String` ids
+    that are introduced in vm_service:11.0.0
+
+[#43638]: https://github.com/dart-lang/sdk/issues/43638
+[#50868]: https://github.com/dart-lang/sdk/issues/50868
+[#51035]: https://github.com/dart-lang/sdk/issues/51035
+
+#### `dart:js_util`
+
+- Added several helper functions to access more JavaScript operators, like
+  `delete` and the `typeof` functionality.
+- `jsify` is now permissive and has inverse semantics to `dartify`.
+- `jsify` and `dartify` both handle types they understand natively more
+  efficiently.
+- Signature of `callMethod` has been aligned with the other methods and
+  now takes `Object` instead of `String`.
+
+### Tools
+
+#### Observatory
+- Observatory is no longer served by default and users should instead use Dart
+  DevTools. Users requiring specific functionality in Observatory should set
+  the `--serve-observatory` flag.
+
+#### Web Dev Compiler (DDC)
+- Removed deprecated command line flags `-k`, `--kernel`, and `--dart-sdk`.
+- The compile time flag `--nativeNonNullAsserts`, which ensures web library APIs
+are sound in their nullability, is by default set to true in sound mode. For
+more information on the flag, see [NATIVE_NULL_ASSERTIONS.md][].
+
+[NATIVE_NULL_ASSERTIONS.md]: https://github.com/dart-lang/sdk/blob/main/sdk/lib/html/doc/NATIVE_NULL_ASSERTIONS.md
+
+#### dart2js
+- The compile time flag `--native-null-assertions`, which ensures web library
+APIs are sound in their nullability, is by default set to true in sound mode,
+unless `-O3` or higher is passed, in which case they are not checked. For more
+information on the flag, see [NATIVE_NULL_ASSERTIONS.md][].
+
+[NATIVE_NULL_ASSERTIONS.md]: https://github.com/dart-lang/sdk/blob/main/sdk/lib/html/doc/NATIVE_NULL_ASSERTIONS.md
+
+#### Dart2js
+
+- Cleanup related to [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  the internal dart2js snapshot fails unless it is called from a supported
+  interface, such as `dart compile js`, `flutter build`, or
+  `build_web_compilers`. This is not expected to be a visible change.
+
+#### Formatter
+
+* Format `sync*` and `async*` functions with `=>` bodies.
+* Don't split after `<` in collection literals.
+* Better indentation of multiline function types inside type argument lists.
+* Fix bug where parameter metadata wouldn't always split when it should.
+
+#### Analyzer
+
+- Most static analysis "hints" are converted to be "warnings," and any
+  remaining hints are intended to be converted soon after the Dart 3.0 release.
+  This means that any (previously) hints reported by `dart analyze` are now
+  considered "fatal" (will result in a non-zero exit code). The previous
+  behavior, where such hints (now warnings) are not fatal, can be achieved by
+  using the `--no-fatal-warnings` flag. This behavior can also be altered, on a
+  code-by-code basis, by [changing the severity of rules] in an analysis
+  options file.
+- Add static enforcement of the SDK-only `@Since` annotation. When code in a
+  package uses a Dart SDK element annotated with `@Since`, analyzer will report
+  a warning if the package's [Dart SDK constraint] allows versions of Dart
+  which don't include that element.
+- Protects the Dart Analysis Server against extreme memory usage by limiting
+  the number of plugins per analysis context to 1. (issue [#50981][]).
+
+[changing the severity of rules]: https://dart.dev/tools/analysis#changing-the-severity-of-rules
+[Dart SDK constraint]: https://dart.dev/tools/pub/pubspec#sdk-constraints
+
+#### Linter
+
+Updates the Linter to `1.35.0`, which includes changes that
+
+- add new lints:
+  - `implicit_reopen`
+  - `unnecessary_breaks`
+  - `type_literal_in_constant_pattern`
+  - `invalid_case_patterns`
+- update existing lints to support patterns and class modifiers
+- remove support for:
+  - `enable_null_safety`
+  - `invariant_booleans`
+  - `prefer_bool_in_asserts`
+  - `prefer_equal_for_default_values`
+  - `super_goes_last`
+- fix `unnecessary_parenthesis` false-positives with null-aware expressions.
+- fix `void_checks` to allow assignments of `Future<dynamic>?` to parameters
+  typed `FutureOr<void>?`.
+- fix `use_build_context_synchronously` in if conditions.
+- fix a false positive for `avoid_private_typedef_functions` with generalized
+  type aliases.
+- update `unnecessary_parenthesis` to detect some doubled parens.
+- update `void_checks` to allow returning `Never` as void.
+- update `no_adjacent_strings_in_list` to support set literals and for- and
+  if-elements.
+- update `avoid_types_as_parameter_names` to handle type variables.
+- update `avoid_positional_boolean_parameters` to handle typedefs.
+- update `avoid_redundant_argument_values` to check parameters of redirecting
+  constructors.
+- improve performance for `prefer_const_literals_to_create_immutables`.
+- update `use_build_context_synchronously` to check context properties.
+- improve `unnecessary_parenthesis` support for property accesses and method
+  invocations.
+- update `unnecessary_parenthesis` to allow parentheses in more null-aware
+  cascade contexts.
+- update `unreachable_from_main` to track static elements.
+- update `unnecessary_null_checks` to not report on arguments passed to
+  `Future.value` or `Completer.complete`.
+- mark `always_use_package_imports` and `prefer_relative_imports` as
+  incompatible rules.
+- update `only_throw_errors` to not report on `Never`-typed expressions.
+- update `unnecessary_lambdas` to not report with `late final` variables.
+- update `avoid_function_literals_in_foreach_calls` to not report with nullable-
+  typed targets.
+- add new lint: `deprecated_member_use_from_same_package` which replaces the
+  soft-deprecated analyzer hint of the same name.
+- update `public_member_api_docs` to not require docs on enum constructors.
+- update `prefer_void_to_null` to not report on as-expressions.
+
+#### Migration tool removal
+
+The null safety migration tool (`dart migrate`) has been removed.  If you still
+have code which needs to be migrated to null safety, please run `dart migrate`
+using Dart version 2.19, before upgrading to Dart version 3.0.
+
+#### Pub
+
+- To preserve compatibility with null-safe code pre Dart 3, Pub will interpret a
+  language constraint indicating a language version of `2.12` or higher and an
+  upper bound of `<3.0.0` as `<4.0.0`.
+
+  For example `>=2.19.2 <3.0.0` will be interpreted as `>=2.19.2 <4.0.0`.
+- `dart pub publish` will no longer warn about `dependency_overrides`. Dependency
+  overrides only take effect in the root package of a resolution.
+- `dart pub token add` now verifies that the given token is valid for including
+  in a header according to [RFC 6750 section
+  2.1](https://www.rfc-editor.org/rfc/rfc6750#section-2.1). This means they must
+  contain only the characters: `^[a-zA-Z0-9._~+/=-]+$`. Before a failure would
+  happen when attempting to send the authorization header.
+- `dart pub get` and related commands will now by default also update the
+  dependencies in the `example` folder (if it exists). Use `--no-example` to
+  avoid this.
+- On Windows the `PUB_CACHE` has moved to `%LOCALAPPDATA%`, since Dart 2.8 the
+  `PUB_CACHE` has been created in `%LOCALAPPDATA%` when one wasn't present.
+  Hence, this only affects users with a `PUB_CACHE` created by Dart 2.7 or
+  earlier. If you have `path/to/.pub-cache/bin` in `PATH` you may need to
+  update your `PATH`.
+
+## 2.19.6 - 2023-03-29
+
+This is a patch release that:
+
+- Fixes an `Out of Memory` exception due to a VM bug. (issue [#50537]).
+
+[#50537]: https://github.com/dart-lang/sdk/issues/50537
+
+## 2.19.5 - 2023-03-22
+
+This is a patch release that:
+
+- Fixes broken usage of `Dart_CObject_Type`. (issue [#51459]).
+
+[#51459]: https://github.com/dart-lang/sdk/issues/51459
+
+## 2.19.4 - 2023-03-08
+
+This is a patch release that:
+
+- Fixes mobile devices vm crashes caused by particular use of RegExp. (issue
+  [#121270][]).
+
+[#121270]: https://github.com/flutter/flutter/issues/121270
+
+## 2.19.3 - 2023-03-01
+
+This is a patch release that:
+
+- Updates DDC test and builder configuration. (issue [#51481][]).
+
+- Protects the Dart Analysis Server against extreme memory usage by limiting
+  the number of plugins per analysis context to 1. (issue [#50981][]).
+
+[#50981]: https://github.com/dart-lang/sdk/issues/50981
+[#51481]: https://github.com/dart-lang/sdk/issues/51481
+
+## 2.19.2 - 2023-02-08
+
+This is a patch release that:
+
+- Fixes a VM crash when mixing the use of double and float calculations in
+  debug/jit configuration. (issue [#50622][]).
+
+- Fixes the compiler crashing when attempting to inline a method with lots of
+  optional parameters with distinct default values. (issue [#119220][]).
+
+- Fixes the `part_of_different_library` error encountered when using `PackageBuildWorkspace`. (issue [#51087][]).
+
+[#50622]: https://github.com/dart-lang/sdk/issues/50622
+[#119220]: https://github.com/flutter/flutter/issues/119220
+[#51087]: https://github.com/dart-lang/sdk/issues/51087
+
+## 2.19.1 - 2023-02-01
+
+This is a patch release that:
+
+- Fixes `pub get` behaviour: In Dart 2.19.0 a `dart pub get` with a
+  `pubspec.lock` created by a 2.18 SDK will unlock all constraints, effectively
+  like a `pub upgrade` (issue [#51166][]).
+
+- Stops rewriting SDK constraints: In Dart 3, a SDK constraint like
+  `>=2.12.0 <3.0.0` gets interpreted by the pub client as `>=2.12.0 <4.0.0` to
+  allow for backwards compatibility (issue [#51101][]).
+
+  This change was intended for Dart 3.0.0 and later, but was landed already in
+  2.19.0. It is now being removed in 2.19.1, as it can give confusing messages
+  such as:
+
+  > Because library requires SDK version >=2.19.2 <4.0.0, version solving failed.
+
+  This reinterpretation no longer happens in Dart 2.19.1.
+
+- Fixes a VM crash caused by incorrect sharing of RegExp between isolates
+  (issue [#51130][]).
+
+[#51166]: https://github.com/dart-lang/sdk/issues/51166
+[#51101]: https://github.com/dart-lang/sdk/issues/51101
+[#51130]: https://github.com/dart-lang/sdk/issues/51130
+
+## 2.19.0 - 2023-01-24
+
+### Language
+
+- **Breaking change** [#49635][]: Flag additional code as unreachable due to
+  types `Null` and `Never`. Several unusual constructs that lead to unreachable
+  code are now recognized by flow analysis:
+
+  - Control flow after an expression of the form `e ?? other` or `e ??= other`,
+    where `e` has static type `Null` and `other` has static type `Never`, is
+    considered unreachable.
+
+  - Control flow predicated on an expression of the form `e is Never` evaluating
+    to `true` is considered unreachable.
+
+  - Control flow predicated on an expression of the form `e is! Never`
+    evaluating to `false` is considered unreachable.
+
+  - Control flow on the RHS of a null-aware access such as `e?.property...`,
+    `e?.property = ...` or `e?.method(...)`, where `e` has static type `Null`,
+    is considered unreachable (Note: this can arise in the presence of extension
+    methods).
+
+  Previously, these behaviors only took effect if `e` was a reference to a local
+  variable.
+
+  Additionally, a type test of the form `v is Never` (where `v` is a local
+  variable) no longer promotes `v` to type `Never`.
+
+[#49635]: https://github.com/dart-lang/sdk/issues/49635
+
+- **Breaking Change** [#49687][]: Don't delegate inaccessible private names to
+  `noSuchMethod`. If a concrete class implements an interface containing a
+  member with a name that's private to different library, and does not inherit
+  an implementation of that interface member, a invocation of that member will
+  result in an exception getting thrown. Previously, such attempts would result
+  in the call being diverted to the `noSuchMethod` method.
+
+  This change closes a loophole in Dart's privacy system, where another library
+  can provide a different implementation of a supposedly private member using
+  `noSuchMethod`, and paves the way for a future implementation of promotion for
+  private final fields (see [#2020][]).
+
+[#49687]: https://github.com/dart-lang/sdk/issues/49687
+[#2020]: https://github.com/dart-lang/language/issues/2020
+
+- **Breaking Change** [#50383][]: Report a compile-time error for all cyclic
+  dependencies during top-level type inference.
+
+  Previously, some of these dependencies were ignored, based on an analysis
+  determining that they could not influence the inferred type. However, this
+  analysis was complex, differed slightly among tools, and had become much more
+  complex due to other changes (especially, enhanced flow analysis).
+
+  With this change, all tools treat these cyclic dependencies in the same way,
+  the analysis is well-understood, and, arguably, the code is more readable.
+
+  Breakage is mitigated by adding a declared type to one top-level declaration
+  per cycle which is now an error.
+
+[#50383]: https://github.com/dart-lang/sdk/issues/50383
+
+- Add support for **unnamed libraries**. Dart language 2.19 allows a library
+  directive to be written without a name (`library;`). A library directive can
+  be used for library-level annotations (such as `@deprecated`) and for
+  library-level documentation comments, and with this new feature, you don't
+  have to provide a unique name for each library directive. Instead, a name can
+  simply be omitted (see [#1073][]).
+
+[#1073]: https://github.com/dart-lang/language/issues/1073
+
+### Libraries
+
+#### `dart:convert`
+
+- **Breaking change** [#34233]: The previously deprecated API
+  [`DEFAULT_BUFFER_SIZE`] in `JsonUtf8Encoder` has been removed.
+
+[#34233]: https://github.com/dart-lang/sdk/issues/34233
+[`DEFAULT_BUFFER_SIZE`]: https://api.dart.dev/stable/2.17.6/dart-convert/JsonUtf8Encoder/DEFAULT_BUFFER_SIZE-constant.html
+
+#### `dart:core`
+
+- Deprecated `FallThroughError`. Has not been thrown since Dart 2.0
+  (see [#49529]).
+- Added `copyWith` extension method on `DateTime` (see [#24644]).
+- Deprecated `RangeError.checkValidIndex` in favor of `IndexError.check`.
+- Deprecated `IndexError` constructor in favor of `IndexError.withLength`
+  constructor.
+- Deprecated `NullThrownError` and `CyclicInitializationError`.
+  Neither error is thrown by null safe code.
+[#49529]: https://github.com/dart-lang/sdk/issues/49529
+[#24644]: https://github.com/dart-lang/sdk/issues/24644
+
+#### `dart:developer`
+
+- **Breaking change** [#34233]: The previously deprecated APIs `kInvalidParams`,
+  `kExtensionError`, `kExtensionErrorMax`, and `kExtensionErrorMin` in
+  [`ServiceExtensionResponse`] have been removed. They have been replaced by
+  `invalidParams`, `extensionError`, `extensionErrorMax`, and
+  `extensionErrorMin`.
+- Deprecated `UserTag.MAX_USER_TAGS` in favor of `UserTag.maxUserTags`.
+
+[#34233]: https://github.com/dart-lang/sdk/issues/34233
+[`ServiceExtensionResponse`]: https://api.dart.dev/stable/2.17.6/dart-developer/ServiceExtensionResponse-class.html#constants
+
+#### `dart:ffi`
+
+- **Breaking change** [#49935]: The runtime type argument of `Pointer` has
+  changed to `Never` in preparation of completely removing the runtime type
+  argument. `Pointer.toString` has changed to not report any type argument.
+
+[#49935]: https://github.com/dart-lang/sdk/issues/49935
+
+#### `dart:html`
+
+- Add constructor and `slice` to `SharedArrayBuffer`.
+- Deprecated `registerElement` and `registerElement2` in `Document` and
+  `HtmlDocument`. These APIs were based on the deprecated Web Components v0.5
+  specification and are not supported by browsers today. These APIs are expected
+  to be deleted in a future release. See the related breaking change request
+  [#49536](https://github.com/dart-lang/sdk/issues/49536).
+
+#### `dart:io`
+
+- **Breaking change** [#49305](https://github.com/dart-lang/sdk/issues/49305):
+  Disallow negative or hexadecimal content-length headers.
+- **Breaking change** [#49647](https://github.com/dart-lang/sdk/issues/49647):
+  `File.create` now takes new optional `exclusive` `bool` parameter, and when it
+  is `true` the operation will fail if target file already exists.
+- **Breaking change** [#49878]: Calling `ResourceHandle.toFile()`,
+  `ResourceHandle.toSocket()`, `ResourceHandle.toRawSocket()` or
+  `ResourceHandle.toRawDatagramSocket()`, more than once now throws a
+  `StateError`.
+
+  The previous behavior would allow multiple Dart objects to refer to the same
+  file descriptor, which would produce errors when one object was closed or
+  garbage collected.
+
+[#49878]: https://github.com/dart-lang/sdk/issues/49878
+
+- Adds three new `FileSystemException` subclasses to handle common error cases:
+
+  - `PathAccessException`: The necessary access rights are not available.
+  - `PathExistsException`: The path being created already exists.
+  - `PathNotFoundException`: The path being accessed does not exist.
+
+[#12461]: https://github.com/dart-lang/sdk/issues/12461
+[#50436]: https://github.com/dart-lang/sdk/issues/50436
+
+#### `dart:isolate`
+
+- Add `Isolate.run` to run a function in a new isolate.
+- **Breaking change**: `SendPort.send` is again applying strict checks to the
+  contents of the message when sending messages between isolates that are not
+  known to share the same code (e.g. an isolate spawned via `Isolate.spawnUri`).
+  These checks were accidentally relaxed in an earlier Dart version allowing
+  all classes from `dart:core` and `dart:collection` through. This for
+  example means that you can't send an instance of a `HashMap` to an isolate
+  spawned via `Isolate.spawnUri`. See [`SendPort.send`] documentation for
+  the full list of restrictions.
+
+[`SendPort.send`]: https://api.dart.dev/stable/dart-isolate/SendPort/send.html
+
+#### `dart:mirrors`
+
+- **Breaking change** [#34233]: The APIs [`MirrorsUsed`] and [`Comment`] have
+  been removed. `MirrorsUsed` was experimental and deprecated; `Comment` was
+  previously used internally in dart2js. Both are no longer functional.
+
+[#34233]: https://github.com/dart-lang/sdk/issues/34233
+[`MirrorsUsed`]: https://api.dart.dev/stable/dart-mirrors/MirrorsUsed-class.html
+[`Comment`]: https://api.dart.dev/stable/dart-mirrors/Comment-class.html
+
+### Other libraries
+
+#### `package:js`
+
+- **Breaking changes to the preview feature `@staticInterop`**:
+  - Classes with this annotation are now disallowed from using `external`
+    generative constructors. Use `external factory`s for these classes instead,
+    and the behavior should be identical. This includes use of synthetic
+    constructors. See [#48730] and [#49941] for more details.
+  - Classes with this annotation's external extension members are now disallowed
+    from using type parameters e.g. `external void method<T>(T t)`. Use a
+    non-`external` extension method for type parameters instead. See [#49350]
+    for more details.
+  - Classes with this annotation should also have the `@JS` annotation. You can
+    also have the `@anonymous` annotation with these two annotations for an
+    object literal constructor, but it isn't required.
+  - Classes with this annotation can not be implemented by classes without this
+    annotation. This is to avoid confusing type behavior.
+
+[#48730]: https://github.com/dart-lang/sdk/issues/48730
+[#49941]: https://github.com/dart-lang/sdk/issues/49941
+[#49350]: https://github.com/dart-lang/sdk/issues/49350
+
+### Tools
+
+#### Analyzer
+
+- add static enforcement of new `mustBeOverridden` annotation, and quick fixes
+- add quick fixes for many diagnostics including compile-time errors, hints, and
+  lints. There are now quick fixes for over 300 diagnostic codes. These lint
+  rules have new fixes: `combinators_ordering`, `dangling_library_doc_comments`,
+  `implicit_call_tearoffs`, `library_annotations`, and
+  `unnecessary_library_directive`.
+- add new hints: `body_might_complete_normally_catch_error`,
+  `cast_from_null_always_fails`, `cast_from_nullable_always_fails`,
+  `deprecated_colon_for_default_value`, and `duplicate_export`
+- remove hint: `invalid_override_different_default_values`
+
+#### Linter
+
+Updated the Linter to `1.31.0`, which includes changes that
+
+- add new lint: `collection_methods_unrelated_type`.
+- add new lint: `combinators_ordering`.
+- add new lint: `dangling_library_doc_comments`.
+- add new lint: `enable_null_safety`.
+- add new lint: `implicit_call_tearoffs`.
+- add new lint: `library_annotations`.
+- add new lint: `unnecessary_library_directive`.
+- add new lint: `unreachable_from_main`.
+- add new lint: `use_string_in_part_of_directives`.
+- fix `no_leading_underscores_for_local_identifiers` to not report super formals
+  as local variables.
+- fix `unnecessary_overrides` false negatives.
+- fix `cancel_subscriptions` for nullable fields.
+- update `library_names` to support unnamed libraries.
+- fix `unnecessary_parenthesis` support for as-expressions.
+- fix `use_build_context_synchronously` to check for context property accesses.
+- fix false positive in `comment_references`.
+- improved unrelated type checks to handle enums and cascades.
+- fix `unnecessary_brace_in_string_interps` for `this` expressions .
+- update `use_build_context_synchronously` for `BuildContext.mounted`.
+- improve `flutter_style_todos` to handle more cases.
+- fix `use_build_context_synchronously` to check for `BuildContext`s in named
+  expressions.
+- fix `exhaustive_cases` to check parenthesized expressions
+- update `avoid_redundant_argument_values` to work with enum declarations.
+- fix `avoid_redundant_argument_values` when referencing required
+  parameters in legacy libraries.
+- fix `use_super_parameters` false positives with repeated super
+  parameter references.
+- update `use_late_for_private_fields_and_variables` to handle enums.
+- fix `prefer_contains` false positives when a start index is non-zero.
+- improve `noop_primitive_operations` to catch `.toString()`
+  in string interpolations.
+- update `public_member_api_docs` to report diagnostics on extension
+  names (instead of bodies).
+- fix `use_colored_box` and `use_decorated_box` to not over-report on containers without
+  a child.
+- fix `unnecessary_parenthesis` false positives on a map-or-set literal at the start of
+  an expression statement.
+- fix `prefer_final_locals` false positives reporting on fields.
+- fix `unnecessary_overrides` to allow overrides on `@Protected`members.
+- fix `avoid_multiple_declarations_per_line` false positives in `for` statements.
+- fix `prefer_final_locals` false positives on declaration lists with at least one
+  non-final variable.
+- fix`use_build_context_synchronously` to handle `await`s in `if` conditions.
+- improves performance for:
+  - `avoid_escaping_inner_quotes`.
+  - `avoid_null_checks_in_equality_operators`.
+  - `avoid_positional_boolean_parameters`.
+  - `avoid_returning_null`.
+  - `avoid_returning_null`.
+  - `avoid_returning_this`.
+  - `cascade_invocations`.
+  - `diagnostic_describe_all_properties`.
+  - `flutter_style_todos`.
+  - `join_return_with_statement`.
+  - `parameter_assignments`.
+  - `prefer_const_constructors`.
+  - `prefer_constructors_over_static_methods`.
+  - `prefer_constructors_over_static_methods`.
+  - `prefer_contains`.
+  - `prefer_foreach`.
+  - `prefer_interpolation_to_compose_strings`.
+  - `prefer_interpolation_to_compose_strings`.
+  - `recursive_getters`.
+  - `tighten_type_of_initializing_formals`.
+  - `unnecessary_lambdas`.
+  - `use_late_for_private_fields_and_variables`.
+
+#### Pub
+
+- Treats packages with sdk constraint lower bound `>=2.12.0` or more and upper
+  bound `<3.0.0` as compatible with `<4.0.0`.
+- Introduces content-hashes in pubspec.lock, to protect against corrupted
+  package repositories.
+
+  These will show up in the lock file on the first run of `dart pub get`.
+
+  See https://dart.dev/go/content-hashes for more details.
+- New flag `dart pub get --enforce-lockfile` will fetch dependencies, but fail
+  if anything deviates from `pubspec.lock`. Useful for ensuring reproducible runs
+  in CI and production.
+- Remove remaining support for `.packages` files. The flag
+  `--legacy-packages-file` is no longer supported.
+- The client will now default to the `pub.dev` repository instead of `pub.dartlang.org`.
+  This will cause a change in `pubspec.lock`.
+- Support a new field [`funding`](https://dart.dev/tools/pub/pubspec#funding) in `pubspec.yaml`.
+- Validate the CRC32c checksum of downloaded archives and retry on failure.
+- `dart pub add foo:<constraint>` with an existing dependency will now update
+  the constraint rather than fail.
+- Update `dart pub publish` to allow `dependency_overrides` in `pubspec.yaml`.
+  They will still cause a publication warning.
+  Note that only `dependency_overrides` from the root package effect resolution.
+- Update `dart pub publish` to require a working resolution.
+  If publishing a breaking release of mutually dependent packages use `dependency_overrides`
+  to obtain a resolution.
+- `dart pub add` will now allow adding multiple packages from any source using
+  the same YAML syntax as in `pubspec.yaml`.
+
+  For example:
+  ```console
+  $ dart pub add retry:^1.0.0 'dev:foo{"git":"https://github.com/foo/foo"}'
+  ```
+- `dart pub publish` will now give a warning if `dart analyze` reports any diagnostics.
+- `dart pub get` now fails gracefully when run from inside the pub-cache.
+- `dart pub publish` now shows the file sizes of large files in your package to
+  prevent accidental publication of large unrelated files.
+- Fix a bug in `dart pub upgrade --major-versions` where packages not requiring
+  major updates would be held back unless needed.
+
+#### dart2js
+
+- **Breaking change** [49473](https://github.com/dart-lang/sdk/issues/49473):
+  dart2js no longer supports HTTP URIs as inputs.
+
+## 2.18.5 - 2022-11-23
+
+- fixes an error on private variable setters in mixins on dart web
+  (issue [#50119][]).
+- fixes the handling of type parameter nullability in factory constructors
+  (issue [#50392][]).
+
+[#50119]: https://github.com/dart-lang/sdk/issues/50119
+[#50392]: https://github.com/dart-lang/sdk/issues/50392
+
+## 2.18.4 - 2022-11-02
+
+This is a patch release that fixes crashes during hot reload
+(issue [flutter/flutter#113540][]).
+
+[flutter/flutter#113540]: https://github.com/flutter/flutter/issues/113540
+
+## 2.18.3 - 2022-10-19
+
+This is a patch release that fixes a regression in code coverage computation
+(issue [#49887][]).
+
+[#49887]: https://github.com/dart-lang/sdk/issues/49887
+
+## 2.18.2 - 2022-09-28
+
+This is a patch release that:
+
+- fixes incorrect behavior in `Uri.parse`.
+- fixes a compiler crash (issue [#50052][]).
+
+### Libraries
+
+#### `dart:core`
+
+- **Security advisory** [CVE-2022-3095](https://github.com/dart-lang/sdk/security/advisories/GHSA-m9pm-2598-57rj):
+  There is a auth bypass vulnerability in Dart SDK, specifically `dart:uri` core
+  library, used to parse and validate URLs. This library is vulnerable to the
+  backslash-trick wherein backslash is not recognized as equivalent to forward
+  slash in URLs.
+
+  The `Uri` class has been changed to parse a backslash in the path or the
+  authority separator of a URI as a forward slash. This affects the `Uri`
+  constructor's `path` parameter, and the `Uri.parse` method.
+  This change was made to not diverge as much from the browser `URL` behavior.
+  The Dart `Uri` class is still not an implementation of the same standard
+  as the browser's `URL` implementation.
+
+[#50052]: https://github.com/dart-lang/sdk/issues/50052
+
+## 2.18.1 - 2022-09-14
+
+This is a patch release that fixes a crash caused by incorrect type inference
+(issues [flutter/flutter#110715][] and [flutter/flutter#111088][]).
+
+[flutter/flutter#110715]: https://github.com/flutter/flutter/issues/110715
+[flutter/flutter#111088]: https://github.com/flutter/flutter/issues/111088
+
+## 2.18.0 - 2022-08-30
+
+### Language
+
+The following features are new in the Dart 2.18 [language version][]. To use
+them, you must set the lower bound on the SDK constraint for your package to
+2.18 or greater (`sdk: '>=2.18.0 <3.0.0'`).
+
+[language version]: https://dart.dev/guides/language/evolution
+
+-  **[Enhanced type inference for generic invocations with function literals][]**:
+   Invocations of generic methods/constructors that supply function literal
+   arguments now have improved type inference. This primarily affects the
+   `Iterable.fold` method. For example, in previous versions of Dart, the
+   compiler would fail to infer an appropriate type for the parameter `a`:
+
+   ```dart
+   void main() {
+     List<int> ints = [1, 2, 3];
+     var maximum = ints.fold(0, (a, b) => a < b ? b : a);
+   }
+   ```
+
+   With this improvement, `a` receives its type from the initial value, `0`.
+
+   On rare occasions, the wrong type will be inferred, leading to a compile-time
+   error, for example in this code, type inference will infer that `a` has a
+   type of `Null`:
+
+   ```dart
+   void main() {
+     List<int> ints = [1, 2, 3];
+     var maximumOrNull = ints.fold(null,
+         (a, b) => a == null || a < b ? b : a);
+   }
+   ```
+
+   This can be worked around by supplying the appropriate type as an explicit
+   type argument to `fold`:
+
+   ```dart
+   void main() {
+     List<int> ints = [1, 2, 3];
+     var maximumOrNull = ints.fold<int?>(null,
+         (a, b) => a == null || a < b ? b : a);
+   }
+   ```
+[Enhanced type inference for generic invocations with function literals]: https://github.com/dart-lang/language/issues/731
+
+- **Breaking Change** [#48167](https://github.com/dart-lang/sdk/issues/48167):
+  Mixin of classes that don't extend `Object` is no longer supported:
+  ```dart
+  class Base {}
+  class Mixin extends Base {}
+  class C extends Base with Mixin {}
+  ```
+  This should instead be written using a mixin declaration of `Mixin`:
+  ```dart
+  class Base {}
+  mixin Mixin on Base {}
+  class C extends Base with Mixin {}
+  ```
+  This feature has not been supported in most compilation targets for some
+  time but is now completely removed.
+
+### Core libraries
+
+#### `dart:async`
+
+- The `Stream.fromIterable` stream can now be listened to more than once.
+
+#### `dart:collection`
+
+- Deprecates `BidirectionalIterator`.
+
+#### `dart:core`
+
+- Allow omitting the `unencodedPath` positional argument to `Uri.http` and
+  `Uri.https` to default to an empty path.
+
+#### `dart:html`
+
+- Add `connectionState` attribute and `connectionstatechange` listener to
+  `RtcPeerConnection`.
+
+#### `dart:io`
+
+- **Breaking Change** [#49045](https://github.com/dart-lang/sdk/issues/49045):
+  The `uri` property of `RedirectException` in `dart:io` has been changed to
+  be nullable. Programs must be updated to handle the `null` case.
+- **Breaking Change** [#34218](https://github.com/dart-lang/sdk/issues/34218):
+  Constants in `dart:io`'s networking APIs following the `SCREAMING_CAPS`
+  convention have been removed (they were previously deprecated). Please use
+  the corresponding `lowerCamelCase` constants instead.
+
+- **Breaking Change** [#45630][]: The Dart VM no longer automatically restores
+    the initial terminal settings upon exit. Programs that change the `Stdin`
+    settings `lineMode` and `echoMode` are now responsible for restoring the
+    settings upon program exit. E.g. a program disabling `echoMode` will now
+    need to restore the setting itself and handle exiting by the appropriate
+    signals if desired:
+
+    ```dart
+    import 'dart:io';
+    import 'dart:async';
+
+    main() {
+      bool echoWasEnabled = stdin.echoMode;
+      try {
+        late StreamSubscription subscription;
+        subscription = ProcessSignal.sigint.watch().listen((ProcessSignal signal) {
+          stdin.echoMode = echoWasEnabled;
+          subscription.cancel();
+          Process.killPid(pid, signal); /* Die by the signal. */
+        });
+        stdin.echoMode = false;
+      } finally {
+        stdin.echoMode = echoWasEnabled;
+      }
+    }
+    ```
+
+    This change is needed to fix [#36453][] where the dart programs not caring
+    about the terminal settings can inadvertently corrupt the terminal settings
+    when e.g. piping into less.
+
+    Furthermore the `echoMode` setting now only controls the `echo` local mode
+    and no longer sets the `echonl` local mode on POSIX systems (which controls
+    whether newline are echoed even if the regular echo mode is disabled). The
+    `echonl` local mode is usually turned off in common shell environments.
+    Programs that wish to control the `echonl` local mode can use the new
+    `echoNewlineMode` setting.
+
+    The Windows console code pages (if not UTF-8) and ANSI escape code support
+    (if disabled) remain restored when the VM exits.
+
+[#45630]: https://github.com/dart-lang/sdk/issues/45630
+[#36453]: https://github.com/dart-lang/sdk/issues/36453
+
+#### `dart:js_util`
+
+- Added `dartify` and a number of minor helper functions.
+
+### Dart VM
+
+Implementation of `async`/`async*`/`sync*` is revamped in Dart VM,
+both in JIT and AOT modes. This also affects Flutter except Flutter Web.
+
+Besides smaller code size and better performance of async methods,
+the new implementation carries a few subtle changes in behavior:
+
+- If `async` method returns before reaching the first `await`, it now
+  returns a completed Future.
+  Previously `async` methods completed resulting Future in separate microtasks.
+
+- Stack traces no longer have duplicate entries for `async` methods.
+
+- New implementation now correctly throws an error if `null` occurs as
+  an argument of a logical expression (`&&` and `||`) which also contains
+  an `await`.
+
+- New implementation avoids unnecessary extending the liveness of local
+  variables in `async`/`async*`/`sync*` methods, which means that unused
+  objects stored in local variables in such methods might be garbage
+  collected earlier than they were before
+  (see issue [#36983](https://github.com/dart-lang/sdk/issues/36983)
+  for details).
+
+### Tools
+
+#### General
+
+- **Breaking Change** [#48272](https://github.com/dart-lang/sdk/issues/48272):
+  The `.packages` file has been fully discontinued. Historically when the
+  commands `dart pub get` or `flutter pub get` are executed, pub resolved all
+  dependencies, and installs those dependencies to the local pub cache. It
+  furthermore created a mapping from each used package to their location on the
+  local file system, and wrote that into two files:
+
+    * `.dart_tool/package_config.json`
+    * `.packages` (deprecated in Dart 2.8.0)
+
+  As of Dart 2.18.0, the `.packages` is now fully desupported, and all tools
+  distributed in, and based on, the Dart SDK no longer support it, and thus
+  solely use the `.dart_tool/package_config.json` file. If you've run `dart pub
+  get` or `flutter pub get` with any Dart SDK from the past few years you
+  already have a `.dart_tool/package_config.json` and thus should not be
+  impacted. You can delete any old `.packages` files.
+
+  If you have any third-party tools that for historical reasons depend on a
+  `.packages` we will support the ability to generate a `.packages` by passing
+  the flag `--legacy-packages-file` to `dart pub get`. This support will be
+  removed in a following stable release.
+
+#### Dart command line
+
+- **Breaking change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The standalone `dart2js` and `dartdevc` tools have been removed as previously
+  announced. `dart2js` is replaced by the `dart compile js` command, `dartdevc`
+  is no longer exposed as a command-line tool.
+
+- **Breaking change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The standalone `dartanalyzer` tool has been removed as previously
+  announced. `dartanalyzer` is replaced by the `dart analyze` command.
+
+#### Analyzer
+
+- added quick fixes for diagnostics: `abstract_field_constructor_initializer`,
+  `abstract_class_member`,
+  [`always_put_control_body_on_new_line`](https://dart.dev/lints/always_put_control_body_on_new_line),
+  [`avoid_print`](https://dart.dev/lints/avoid_print),
+  [`avoid_renaming_method_parameters`](https://dart.dev/lints/avoid_renaming_method_parameters),
+  [`discarded_futures`](https://dart.dev/lints/discarded_futures),
+  `enum_with_abstract_member`, `non_bool_condition`,
+  `super_formal_parameter_without_associated_named`,
+  [`unawaited_futures`](https://dart.dev/lints/unawaited_futures),
+  `unnecessary_final` `unused_element_parameter`,
+- added new Hint: `deprecated_export_use`
+
+#### Linter
+
+Updated the Linter to `1.25.0`, which includes changes that
+
+- add new lint: `discarded_futures`.
+- add new lint: `unnecessary_null_aware_operator_on_extension_on_nullable`.
+- add new lint: `unnecessary_to_list_in_spreads`.
+- improve message and highlight range for `no_duplicate_case_values`
+- improve performance for `lines_longer_than_80_chars`,
+  `prefer_const_constructors_in_immutables`, and
+  `prefer_initializing_formals`.
+- fix `prefer_final_parameters` to support super parameters.
+- fix `unawaited_futures` to handle string interpolated
+  futures.
+- update `use_colored_box` to not flag nullable colors,
+- fix `no_leading_underscores_for_local_identifiers`
+  to lint local function declarations.
+- fix `avoid_init_to_null` to correctly handle super
+  initializing defaults that are non-null.
+- update `no_leading_underscores_for_local_identifiers`
+  to allow identifiers with just underscores.
+- fix `flutter_style_todos` to support usernames that
+  start with a digit.
+- update `require_trailing_commas` to handle functions
+  in asserts and multi-line strings.
+- update `unsafe_html` to allow assignments to
+  `img.src`.
+- fix `unnecessary_null_checks` to properly handle map
+  literal entries.
+
+#### Pub
+
+* `dart pub get` and `dart pub upgrade` no longer create the
+  `.packages` file. For details, see breaking change #48272 above.
+* `dart pub outdated` now shows which of your dependencies are discontinued.
+* `dart pub publish` will now list all the files it is about to publish.
+
+## 2.17.7 - 2022-08-24
+
+This is a patch release that:
+
+- fixes a crash in the debugger (issue [#49209][]).
+
+[#49209]: https://github.com/dart-lang/sdk/issues/49209
+
+## 2.17.6 - 2022-07-13
+
+This is a patch release that:
+
+- improves code completion for Flutter (issue [#49054][]).
+- fixes a crash on ARM (issue [#106510][]).
+- fixes a compiler crash with Finalizable parameters (issue [#49402][]).
+
+[#49054]: https://github.com/dart-lang/sdk/issues/49054
+[#106510]: https://github.com/flutter/flutter/issues/106510
+[#49402]: https://github.com/dart-lang/sdk/issues/49402
+
+## 2.17.5 - 2022-06-22
+
+This is a patch release that:
+
+- improves analysis of enums and switch (issue [#49188][]).
+- fixes a compiler crash when initializing Finalizable objects
+  (issue [#49075][]).
+
+[#49188]: https://github.com/dart-lang/sdk/issues/49188
+[#49075]: https://github.com/dart-lang/sdk/issues/49075
+
+## 2.17.3 - 2022-06-01
+
+This is a patch release that fixes:
+
+- a Dart VM compiler crash (issue [#100375][]).
+- code completion when writing method overrides (issue [#49027][]).
+- the `dart pub login` command (issue [#3424][]).
+- analysis of enhanced enums (issue [#49097][]).
+
+[#100375]: https://github.com/flutter/flutter/issues/100375
+[#49027]: https://github.com/dart-lang/sdk/issues/49027
+[#3424]: https://github.com/dart-lang/pub/issues/3424
+[#49097]: https://github.com/dart-lang/sdk/issues/49097
+
+## 2.17.1 - 2022-05-18
+
+This is a patch release that fixes:
+
+- an analyzer plugin crash (issue [#48682][]).
+- Dart FFI support for `late` `Finalizable` variables (issue [#49024]).
+- `dart compile` on macOS 10.15 (issue [#49010][]).
+
+[#48682]: https://github.com/dart-lang/sdk/issues/48682
+[#49024]: https://github.com/dart-lang/sdk/issues/49024
+[#49010]: https://github.com/dart-lang/sdk/issues/49010
+
+## 2.17.0 - 2022-05-11
+
+### Language
+
+The following features are new in the Dart 2.17 [language version][]. To use
+them, you must set the lower bound on the SDK constraint for your package to
+2.17 or greater (`sdk: '>=2.17.0 <3.0.0'`).
+
+[language version]: https://dart.dev/guides/language/evolution
+
+-   **[Enhanced enums with members][]**: Enum declarations can now define
+    members including fields, constructors, methods, getters, etc. For example:
+
+    ```dart
+    enum Water {
+      frozen(32),
+      lukewarm(100),
+      boiling(212);
+
+      final int tempInFahrenheit;
+      const Water(this.tempInFahrenheit);
+
+      @override
+      String toString() => "The $name water is $tempInFahrenheit F.";
+    }
+    ```
+
+    Constructors must be `const` since enum values are always constants. If the
+    constructor takes arguments, they are passed when the enum value is
+    declared.
+
+    The above enum can be used like so:
+
+    ```dart
+    void main() {
+      print(Water.frozen); // prints "The frozen water is 32 F."
+    }
+    ```
+
+[enhanced enums with members]: https://github.com/dart-lang/language/blob/master/accepted/future-releases/enhanced-enums/feature-specification.md
+
+-   **[Super parameters][]**: When extending a class whose constructor takes
+    parameters, the subclass constructor needs to provide arguments for them.
+    Often, these are passed as parameters to the subclass constructor, which
+    then forwards them to the superclass constructor. This is verbose because
+    the subclass constructor must list the name and type of each parameter in
+    its parameter list, and then explicitly forward each one as an argument to
+    the superclass constructor.
+
+    [@roy-sianez][] suggested [allowing `super.`][super dot] before a subclass
+    constructor parameter to implicitly forward it to the corresponding
+    superclass constructor parameter. Applying this feature to Flutter
+    eliminated [nearly 2,000 lines of code][flutter super]. For example, before:
+
+    ```dart
+    class CupertinoPage<T> extends Page<T> {
+      const CupertinoPage({
+        required this.child,
+        this.maintainState = true,
+        this.title,
+        this.fullscreenDialog = false,
+        LocalKey? key,
+        String? name,
+        Object? arguments,
+        String? restorationId,
+      }) : super(
+            key: key,
+            name: name,
+            arguments: arguments,
+            restorationId: restorationId,
+          );
+
+      // ...
+    }
+    ```
+
+    And using super parameters:
+
+    ```dart
+    class CupertinoPage<T> extends Page<T> {
+      const CupertinoPage({
+        required this.child,
+        this.maintainState = true,
+        this.title,
+        this.fullscreenDialog = false,
+        super.key,
+        super.name,
+        super.arguments,
+        super.restorationId,
+      });
+
+      // ...
+    }
+    ```
+
+    From our analysis, over 90% of explicit superclass constructor calls can be
+    completely eliminated, using `super.` parameters instead.
+
+[super parameters]: https://github.com/dart-lang/language/blob/master/working/1855%20-%20super%20parameters/proposal.md
+[@roy-sianez]: https://github.com/roy-sianez
+[super dot]: https://github.com/dart-lang/language/issues/1855
+[flutter super]: https://github.com/flutter/flutter/pull/100905/files
+
+-   **[Named args everywhere][]**: In a function call, Dart requires positional
+    arguments to appear before named arguments. This can be frustrating for
+    arguments like collection literals and function expressions that look best
+    as the last argument in the argument list but are positional, like the
+    `test()` function in the [test package][]:
+
+    ```dart
+    main() {
+      test('A test description', () {
+        // Very long function body here...
+      }, skip: true);
+    }
+    ```
+
+    It would be better if the `skip` argument appeared at the top of the call
+    to `test()` so that it wasn't easily overlooked, but since it's named and
+    the test body argument is positional, `skip` must be placed at the end.
+
+    Dart 2.17 removes this restriction. Named arguments can be freely
+    interleaved with positional arguments, allowing code like:
+
+    ```dart
+    main() {
+      test(skip: true, 'A test description', () {
+        // Very long function body here...
+      });
+    }
+    ```
+
+[named args everywhere]: https://github.com/dart-lang/language/blob/master/accepted/future-releases/named-arguments-anywhere/feature-specification.md
+[test package]: https://pub.dev/packages/test
+
+### Core libraries
+
+#### `dart:core`
+
+- Add `Finalizer` and `WeakReference` which can potentially detect when
+  objects are "garbage collected".
+- Add `isMimeType` method to `UriData` class, to allow case-insensitive
+  checking of the MIME type.
+- Add `isCharset` and `isEncoding` methods to `UriData` class,
+  to allow case-insensitive and alternative-encoding-name aware checking
+  of the MIME type "charset" parameter.
+- Make `UriData.fromString` and `UriData.fromBytes` recognize and omit
+  a "text/plain" `mimeType` even if it is not all lower-case.
+
+#### `dart:ffi`
+
+- Add `ref=` and `[]=` methods to the `StructPointer` and `UnionPointer`
+  extensions. They copy a compound instance into a native memory region.
+- Add `AbiSpecificInteger`s for common C types:
+  - `char`
+  - `unsigned char`
+  - `signed char`
+  - `short`
+  - `unsigned short`
+  - `int`
+  - `unsigned int`
+  - `long`
+  - `unsigned long`
+  - `long long`
+  - `unsigned long long`
+  - `uintptr_t`
+  - `size_t`
+  - `wchar_t`
+- Add `NativeFinalizer` which can potentially detect when objects are
+  "garbage collected". `NativeFinalizer`s run native code where `dart:core`'s
+  `Finalizer`s run Dart code on finalization.
+
+#### `dart:html`
+
+- Add `scrollIntoViewIfNeeded` to `Element`. Previously, this method was nested
+  within `scrollIntoView` based on the `ScrollAlignment` value. `scrollIntoView`
+  is unchanged for now, but users who intend to use the native
+  `Element.scrollIntoViewIfNeeded` should use the new `scrollIntoViewIfNeeded`
+  definition instead.
+- Change `Performance.mark` and `Performance.measure` to accept their different
+  overloads. `mark` can now accept a `markOptions` map, and `measure` can now
+  accept a `startMark` and `endMark`, or a `measureOptions` map. Both methods
+  return their correct return types now as well - `PerformanceEntry?` and
+  `PerformanceMeasure?`, respectively.
+
+#### `dart:indexed_db`
+
+- `IdbFactory.supportsDatabaseNames` has been deprecated. It will always return
+  `false`.
+
+#### `dart:io`
+
+- **Breaking Change** [#47887](https://github.com/dart-lang/sdk/issues/47887):
+  `HttpClient` has a new `connectionFactory` property, which allows socket
+  creation to be customized. Classes that `implement HttpClient` may be broken
+  by this change. Add the following method to your classes to fix them:
+
+  ```dart
+  void set connectionFactory(
+      Future<ConnectionTask<Socket>> Function(
+              Uri url, String? proxyHost, int? proxyPort)?
+          f) =>
+      throw UnsupportedError("connectionFactory not implemented");
+  ```
+
+- **Breaking Change** [#48093](https://github.com/dart-lang/sdk/issues/48093):
+  `HttpClient` has a new `keyLog` property, which allows TLS keys to be logged
+  for debugging purposes. Classes that `implement HttpClient` may be broken by
+  this change. Add the following method to your classes to fix them:
+
+  ```dart
+  void set keyLog(Function(String line)? callback) =>
+      throw UnsupportedError("keyLog not implemented");
+  ```
+
+- **Breaking Change** [#34218](https://github.com/dart-lang/sdk/issues/34218):
+  Constants in `dart:io` following the `SCREAMING_CAPS` convention have been
+  removed (they were previously deprecated).  Please use the corresponding
+  `lowerCamelCase` constants instead.
+- **Breaking Change** [#48513](https://github.com/dart-lang/sdk/issues/48513):
+  Add a new `allowLegacyUnsafeRenegotiation` property to `SecurityContext`,
+  which allows TLS renegotiation for client secure sockets.
+- Add a optional `keyLog` parameter to `SecureSocket.connect` and
+  `SecureSocket.startConnect`.
+- Deprecate `SecureSocket.renegotiate` and `RawSecureSocket.renegotiate`,
+  which were no-ops.
+
+### Tools
+
+#### Dart command line
+
+- **Breaking change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The standalone `dart2js` tool has been
+  marked deprecated as previously announced.
+  Its replacement is the `dart compile js` command.
+  Should you find any issues, or missing features, in the replacement
+  command, kindly file [an issue](https://github.com/dart-lang/sdk/issues/new).
+
+- **Breaking change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The standalone `dartdevc` tool has been marked deprecated as previously
+  announced and will be deleted in a future Dart stable release.  This tool
+  was intended for use only by build systems like bazel, `build_web_compilers`
+  and `flutter_tools`. The functionality remains available for those systems,
+  but it is no longer exposed as a command-line tool in the SDK.
+  Please share any concerns in the
+  [breaking change tracking issue](https://github.com/dart-lang/sdk/issues/46100).
+
+- **Breaking change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The standalone `dartdoc` tool has been removed as
+  previously announced. Its replacement is the `dart doc` command.
+
+- The template names used in the `dart create` command have been simplified,
+  and the current template names are now the set shown below. (Note: for
+  backwards compatibility the former template names can still be used.)
+```
+          [console] (default)    A command-line application.
+          [package]              A package containing shared Dart libraries.
+          [server-shelf]         A server app using package:shelf.
+          [web]                  A web app that uses only core Dart libraries.
+```
+
+#### Analyzer
+
+- added quick fixes for diagnostics:
+  [`always_use_package_imports`](https://dart.dev/lints/always_use_package_imports),
+  [`avoid_void_async`](https://dart.dev/lints/avoid_void_async),
+  [`cascade_invocations`](https://dart.dev/lints/cascade_invocations),
+  `default_list_constructor`,
+  [`must_call_super`](https://dart.dev/tools/diagnostic-messages#must_call_super),
+  [`no_leading_underscores_for_local_identifiers`](https://dart.dev/lints/no_leading_underscores_for_local_identifiers),
+  [`null_check_on_nullable_type_parameter`](https://dart.dev/lints/null_check_on_nullable_type_parameter),
+  [`prefer_function_declarations_over_variables`](https://dart.dev/lints/prefer_function_declarations_over_variables),
+  [`sort_constructors_first`](https://dart.dev/lints/sort_constructors_first),
+  [`sort_unnamed_constructors_first`](https://dart.dev/lints/sort_unnamed_constructors_first),
+  `undefined_enum_constant`,
+  [`unnecessary_late`](https://dart.dev/lints/unnecessary_late),
+  `unnecessary_null_aware_assignments`,
+  [`use_enums`](https://dart.dev/lints/use_enums),
+  [`use_raw_strings`](https://dart.dev/lints/use_raw_strings),
+  [`use_super_parameters`](https://dart.dev/lints/use_super_parameters),
+  `var_return_type`
+- added many errors for invalid enhanced enums
+- added new Hint: [`unnecessary_final`](https://dart.dev/tools/diagnostic-messages#unnecessary_final)
+- added new FFI error: `compound_implements_finalizable`
+- improved errors for invalid Unicode escapes in source code
+
+#### Linter
+
+Updated the Linter to `1.22.0`, which includes changes that
+
+- fixes null-safe variance exceptions in `invariant_booleans`.
+- updates `depend_on_referenced_packages` to treat `flutter_gen` as a virtual
+  package, not needing an explicit dependency.
+- updates `unnecessary_null_checks` and
+  `null_check_on_nullable_type_parameter` to handle
+  list/set/map literals, and `yield` and `await` expressions.
+- fixes `unnecessary_null_aware_assignments` property-access
+  false positives.
+- adds new lint: `use_super_parameters`.
+- adds new lint: `use_enums`.
+- adds new lint: `use_colored_box`.
+- improves performance for `sort_constructors`.
+- improves docs for `always_use_package_imports`,
+  `avoid_print`, and `avoid_relative_lib_imports` .
+- updates `avoid_void_async` to skip `main` functions.
+- updates `prefer_final_parameters` to not super on super params.
+- updates lints for enhanced-enums and super-initializer language
+  features.
+- updates `unnecessary_late` to report on variable names.
+- marks `null_check_on_nullable_type_parameter` stable.
+
+#### Dartdoc
+
+Updated dartdoc to 5.1.0, which includes changes that
+
+- support the enhanced enums feature
+- remove superfluous `[...]` links
+- fix `categoryOrder` option
+- display categorized extensions
+- add annotations to extensions
+- make minor improvements to performance
+
+## 2.16.2 - 2022-03-24
+
+This is a patch release that fixes a dart2js crash when building some Flutter
+web apps (issue [#47916][]).
+
+[#47916]: https://github.com/dart-lang/sdk/issues/47916
+
+## 2.16.1 - 2022-02-09
+
+This is a patch release that fixes an AOT precompiler crash when building some
+Flutter apps (issue [flutter/flutter#97301][]).
+
+[flutter/flutter#97301]: https://github.com/flutter/flutter/issues/97301
+
+## 2.16.0 - 2022-02-03
+
+### Core libraries
+
+#### `dart:core`
+
+- Add `Error.throwWithStackTrace` which can `throw` an
+  error with an existing stack trace, instead of creating
+  a new stack trace.
+
+#### `dart:ffi`
+
+- Add `Abi` and `AbiSpecificInteger`. These enable specifying integers which
+  have different sizes/signs per ABI (hardware and OS combination).
+
+#### `dart:io`
+
+- **Security advisory**
+  [CVE-2022-0451](https://github.com/dart-lang/sdk/security/advisories/GHSA-c8mh-jj22-xg5h),
+  **breaking change** [#45410](https://github.com/dart-lang/sdk/issues/45410):
+  `HttpClient` no longer transmits some headers (i.e. `authorization`,
+  `www-authenticate`, `cookie`, `cookie2`) when processing redirects to a
+  different domain.
+- **Breaking change** [#47653](https://github.com/dart-lang/sdk/issues/47653):
+  On Windows, `Directory.rename` will no longer delete a directory if
+  `newPath` specifies one. Instead, a `FileSystemException` will be thrown.
+- **Breaking change** [#47769](https://github.com/dart-lang/sdk/issues/47769):
+  The `Platform.packageRoot` API has been removed. It had been marked deprecated
+  in 2018, as it doesn't work with any Dart 2.x release.
+- Add optional `sourcePort` parameter to `Socket.connect`, `Socket.startConnect`, `RawSocket.connect` and `RawSocket.startConnect`
+
+#### `dart:isolate`
+
+- **Breaking change** [#47769](https://github.com/dart-lang/sdk/issues/47769):
+The `Isolate.packageRoot` API has been removed. It had been marked deprecated
+in 2018, as it doesn't work with any Dart 2.x release.
+
+### Tools
+
+#### Dart command line
+
+- **Breaking change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The standalone `dartanalyzer` tool has been
+  marked deprecated as previously announced.
+  Its replacement is the `dart analyze` command.
+  Should you find any issues, or missing features, in the replacement
+  command, kindly file [an issue][].
+
+[an issue]: https://github.com/dart-lang/sdk/issues/new
+
+- **Breaking change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The standalone `dartdoc` tool has been
+  marked deprecated as previously announced.
+  Its replacement is the `dart doc` command.
+  Should you find any issues, or missing features, in the replacement
+  command, kindly file [an issue][].
+
+[an issue]: https://github.com/dart-lang/sdk/issues/new
+
+- **Breaking Change** [#46100](https://github.com/dart-lang/sdk/issues/46100):
+  The deprecated standalone `pub` tool has been removed.
+  Its replacement is the `dart pub` command.
+  Should you find any issues, or missing features, in the replacement
+  command, kindly file [an issue][].
+
+[an issue]: https://github.com/dart-lang/pub/issues/new
+
+#### Pub
+
+- Fixed race conditions in `dart pub get`, `dart run` and `dart pub global run`.
+  It should now be safe to run these concurrently.
+- If (when) Pub crashes it will save a verbose log in
+  `$PUB_CACHE/log/pub_log.txt` This can be used for filing issues to the issue
+  tracker.
+
+  `dart --verbose pub [command]` will also cause the log file to be written.
+- `dart pub global activate --source=git` now takes arguments `--git-path` to
+  specify the path of the activated package in the pubspec and `--git-ref` to
+  specify the branch or revision to check out.
+- `dart pub add` can now add multiple packages in one command.
+- `dart pub token add` can now add a token for [pub.dev](https://pub.dev).
+- `dart pub uploader` has been removed. To manage uploaders for a package use
+  the `https://pub.dev/<packagename>/admin` web-interface.
+- Pub now supports a separate `pubspec_overrides.yaml` file that can contain
+  `dependency_overrides`. This makes it easier to avoid checking the local
+  overrides into version control.
+
+#### Linter
+
+Updated the Linter to `1.18.0`, which includes changes that
+
+- extends `camel_case_types` to cover enums.
+- fixes `no_leading_underscores_for_local_identifiers` to not
+  mis-flag field formal parameters with default values.
+- fixes `prefer_function_declarations_over_variables` to not
+  mis-flag non-final fields.
+- improves performance for `prefer_contains`.
+- updates `exhaustive_cases` to skip deprecated values that
+  redirect to other values.
+- adds new lint: `unnecessary_late`.
+- improves docs for `prefer_initializing_formals`.
+- updates `secure_pubspec_urls` to check `issue_tracker` and
+  `repository` entries.
+- adds new lint: `conditional_uri_does_not_exist`.
+- improves performance for
+  `missing_whitespace_between_adjacent_strings`.
+- adds new lint: `avoid_final_parameters`.
+- adds new lint: `no_leading_underscores_for_library_prefixes`.
+- adds new lint: `no_leading_underscores_for_local_identifiers`.
+- adds new lint: `secure_pubspec_urls`.
+- adds new lint: `sized_box_shrink_expand`.
+- adds new lint: `use_decorated_box`.
+- improves docs for `omit_local_variable_types`.
+
+## 2.15.1 - 2021-12-14
+
+This is a patch release that fixes:
+
+- an AOT compilation failure in some Flutter apps (issue [#47878][]).
+- `dart pub publish` for servers with a path in the URL (pr
+  [dart-lang/pub#3244][]).
+
+[#47878]: https://github.com/dart-lang/sdk/issues/47878
+[dart-lang/pub#3244]: https://github.com/dart-lang/pub/pull/3244
+
+## 2.15.0 - 2021-12-08
+
+- **Security advisory**
+  [CVE-2021-22567](https://github.com/dart-lang/sdk/security/advisories/GHSA-8pcp-6qc9-rqmv):
+  Bidirectional Unicode text can be interpreted and compiled differently than
+  how it appears in editors and code-review tools. Exploiting this an attacker
+  could embed source that is invisible to a code reviewer but that modifies the
+  behavior of a program in unexpected ways. Dart 2.15.0 introduces new analysis
+  warnings that flags the use of these.
+
+- **Security advisory**
+  [CVE-2021-22568](https://github.com/dart-lang/sdk/security/advisories/GHSA-r32f-vhjp-qhj7):
+  A malicious third-party package repository may impersonate a user on pub.dev
+  for up to one hour after the user has published a package to that third-party
+  package repository using `dart pub publish`. As of Dart SDK version 2.15.0
+  requests to third-party package repositories will no longer include an OAuth2
+  `access_token` intended for pub.dev.
+
+### Language
+
+The following features are new in the Dart 2.15 [language version][]. To use
+them, you must set the lower bound on the SDK constraint for your package to
+2.15 or greater (`sdk: '>=2.15.0 <3.0.0'`).
+
+[language version]: https://dart.dev/guides/language/evolution
+
+- **[Constructor tear-offs][]**: Previous Dart versions allowed a method on an
+  instance to be passed as a closure, and similarly for static methods. This is
+  commonly referred to as "closurizing" or "tearing off" a method. Constructors
+  were not previously eligible for closurization, forcing users to explicitly
+  write wrapper functions when using constructors as first class functions.
+  See the calls to `map()` in this example:
+
+  ```dart
+  class A {
+    int x;
+    A(this.x);
+    A.fromString(String s) : x = int.parse(s);
+  }
+
+  void main() {
+    var listOfInts = [1, 2, 3];
+    var listOfStrings = ["1", "2", "3"];
+    for(var a in listOfInts.map((x) => A(x))) {
+      print(a.x);
+    }
+    for(var a in listOfStrings.map((x) => A.fromString(x))) {
+      print(a.x);
+    }
+  }
+  ```
+
+  New in Dart 2.15, constructors are now allowed to be torn off. Named
+  constructors are closurized using their declared name (here `A.fromString`).
+  To closurize unnamed constructors, use the keyword `new` (here `A.new`).
+  The above example may now be written as:
+
+  ```dart
+  class A {
+    int x;
+    A(this.x);
+    A.fromString(String s) : x = int.parse(s);
+  }
+
+  void main() {
+    var listOfInts = [1, 2, 3];
+    var listOfStrings = ["1", "2", "3"];
+    for(A a in listOfInts.map(A.new)) {
+      print(a.x);
+    }
+    for(A a in listOfStrings.map(A.fromString)) {
+      print(a.x);
+    }
+  }
+  ```
+
+  Constructors for generic classes may be torn off as generic functions, or
+  instantiated at the tear-off site. In the following example, the tear-off
+  `G.new` is used to initialize the variable `f` produces a generic function
+  which may be used to produce an instance of `G<T>` for any type `T` provided
+  when `f` is called. The tear-off `G<String>.new` is used to initialize the
+  variable `g` to produce a non-generic function which may only be used
+  to produce instances of type `G<String>`.
+
+  ```dart
+  class G<T> {
+    T x;
+    G(this.x);
+  }
+
+  void main() {
+    G<T> Function<T>(T x) f = G.new;
+    var x = f<int>(3);
+    G<String> Function(String y) g = G<String>.new;
+    var y = g("hello");
+  }
+  ```
+
+[constructor tear-offs]: https://github.com/dart-lang/language/blob/master/accepted/2.15/constructor-tearoffs/feature-specification.md
+
+- **[Generic type literals][explicit instantiation]**: Previous Dart versions
+  allowed class names to be used as type literals. So for example,`int` may be
+  used as an expression, producing a value of type `Type`. Generic classes (e.g.
+  `List`) could be referred to by name as an expression, but no type arguments
+  could be provided and so only the `dynamic` instantiation could be produced
+  directly as an expression without using indirect methods:
+
+  ```dart
+  // Workaround to capture generic type literals.
+  Type typeOf<T>() => T;
+
+  void main() {
+    var x = int; // The Type literal corresponding to `int`.
+    var y = List; // The Type literal corresponding to `List<dynamic>`.
+    // Use workaround to capture generic type literal.
+    var z = typeOf<List<int>>(); // The Type literal for `List<int>`.
+  }
+  ```
+
+  New in Dart 2.15, instantiations of generic classes may now be used as Type
+  literals:
+
+  ```dart
+  void main() {
+    var x = int; // The Type literal corresponding to `int`.
+    var y = List; // The Type literal corresponding to `List<dynamic>`.
+    var z = List<int>; // The Type literal corresponding to `List<int>`.
+  }
+  ```
+
+- **[Explicit generic method instantiations][explicit instantiation]**: Previous
+  Dart versions allowed generic methods to be implicitly specialized (or
+  "instantiated") to non-generic versions when assigned to a location with a
+  compatible monomorphic type. Example:
+
+  ```dart
+  // The generic identity function.
+  T id<T>(T x) => x;
+
+  void main() {
+    // Initialize `intId` with a version of `id` implicitly specialized to
+    // `int`.
+    int Function(int) intId = id;
+    print(intId(3));
+    // Initialize `stringId` with a version of `id` implicitly specialized to
+    // `String`.
+    String Function(String) stringId = id;
+    print(stringId("hello"));
+  }
+  ```
+
+  New in Dart 2.15, generic methods may be explicitly instantiated using the
+  syntax `f<T>` where `f` is the generic method to specialize and `T` is the
+  type argument (in general, type arguments) to be used to specialize the
+  method. Example:
+
+  ```dart
+  // The generic identity function.
+  T id<T>(T x) => x;
+
+  void main() {
+    // Initialize `intId` with a version of `id` explicitly specialized to
+    // `int`.
+    var intId = id<int>;
+    print(intId(3));
+    // Initialize `stringId` with a version of `id` explicitly specialized to
+    // `String`.
+    var stringId = id<String>;
+    print(stringId("hello"));
+  }
+  ```
+
+[explicit instantiation]: https://github.com/dart-lang/language/blob/master/accepted/2.15/constructor-tearoffs/feature-specification.md#explicitly-instantiated-classes-and-functions
+
+- **[Generic instantiation of function objects][object instantiation]**: Generic
+  function instantiation was previously restricted to function declarations. For
+  example, as soon as a function had been torn off, it could not be
+  instantiated:
+
+  ```dart
+  // Before Dart 2.15:
+  X id<X>(X x) => x;
+
+  void main() {
+    var fo = id; // Tear off `id`, creating a function object.
+    var c1 = fo<int>; // Compile-time error: can't instantiate `fo`.
+    int Function(int) c2 = fo; // Same compile-time error.
+    // Constants are treated the same.
+  }
+  ```
+
+  New in Dart 2.15, this restriction has been lifted. It is now possible
+  to obtain a generic instantiation of an existing function object, both
+  explicitly and implicitly (again, this works the same for non-constants):
+
+  ```dart
+  X id<X>(X x) => x;
+  X other<X>(X x) => throw x;
+
+  void main() {
+    const fo = id; // Tear off `id`, creating a function object.
+
+    // Generic function instantiation on `fo` is no longer an error.
+    const c1 = fo<int>; // OK.
+    const int Function(int) c2 = fo; // OK.
+
+    // This also generalizes function instantiation because we can,
+    // e.g., use non-trivial expressions and go via a constructor.
+    const c3 = A(true); // OK.
+  }
+
+  class A {
+    final int Function(int) x;
+    // `(...)<T>` is now allowed, also in a `const` constructor.
+    const A(bool b): x = (b ? id : other)<int>;
+  }
+  ```
+
+[Object instantiation]: https://github.com/dart-lang/language/pull/1812
+
+- Annotations on type parameters of classes can no longer refer to class members
+  without a prefix.  For example, this used to be permitted:
+
+  ```dart
+  class C<@Annotation(foo) T> {
+    static void foo() {}
+  }
+  ```
+
+  Now, the reference must be qualified with the class name, i.e.:
+
+  ```dart
+  class C<@Annotation(C.foo) T> {
+    static void foo() {}
+  }
+  ```
+
+  This brings the implementation behavior in line with the spec.
+
+- Initializer expressions on implicitly typed condition variables can now
+  contribute to type promotion.  For example, this program no longer produces a
+  compile-time error:
+
+  ```dart
+  f(int? i) {
+    var iIsNull = i == null;
+    if (!iIsNull) {
+      print(i + 1); // OK, because `i` is known to be non-null.
+    }
+  }
+  ```
+
+  Previously, the above program had a compile-time error due to a bug
+  ([#1785][]) in type promotion which prevented the initializer expression
+  (`i == null`) from being accounted for when the variable in question
+  (`iIsNull`) lacked an explicit type.
+
+  To avoid causing problems for packages that are intended to work with older
+  versions of Dart, the fix only takes effect when the minimum SDK of the source
+  packages is 2.15 or greater.
+
+[#1785]: https://github.com/dart-lang/language/issues/1785
+
+- Restrictions on members of a class with a constant constructor are relaxed
+  such that they only apply when the class has a _generative_ constant
+  constructor. For example, this used to be an error, but is now permitted:
+
+  ```dart
+  abstract class A {
+    const factory A() = B;
+    var v1;
+    late final v2 = Random().nextInt(10);
+    late final v3;
+  }
+
+  class B implements A {
+    const B([this.v3 = 1]);
+    get v1 => null;
+    set v1(_) => throw 'Cannot mutate B.v1';
+    final v2 = 0;
+    final v3;
+    set v3(_) => throw 'Cannot initialize B.v3';
+  }
+  ```
+
+  This implements a relaxation of the specified rule for a `late final`
+  instance variable, and it brings the implementation behavior in line with
+  the specification in all other cases.
+
+- **Function object canonicalization and equality**: Several corner cases in the
+  area of function object canonicalization and function object equality have
+  been updated, such that all tools behave in the same way, and the behavior
+  matches the specification.
+
+  In particular, function objects are now equal when they are obtained by
+  generic instantiation from the same function with the same actual type
+  arguments, even when that type argument is not known at compile time.
+  When the expressions are constant then the function objects are identical.
+  Constant expressions are treated as such even when they do not occur in a
+  constant context (e.g., `var f = top;`).
+
+### Core libraries
+
+#### `dart:async`
+
+- Make the `unawaited` function's argument nullable, to allow calls like
+  `unawaited(foo?.bar())`.
+
+#### `dart:cli`
+
+- The experimental `waitFor` functionality, and the library containing only that
+  function, are now deprecated.
+
+#### `dart:core`
+
+- Add extension `name` getter on enum values.
+- Add `Enum.compareByIndex` helper function for comparing enum values by index.
+- Add `Enum.compareByName` helper function for comparing enum values by name.
+- Add extension methods on `Iterable<T extends Enum>`, intended for
+  `SomeEnumType.values` lists, to look up values by name.
+- Deprecate `IntegerDivisionByZeroException`.
+  Makes the class also implement `Error`. Code throwing the exception will be
+  migrated to throwing an `Error` instead until the class is unused and
+  ready to be removed.
+  Code catching the class should move to catching `Error` instead
+  (or, for integers, check first for whether it's dividing by zero).
+
+#### `dart:ffi`
+
+- Add `Bool` native type.
+
+#### `dart:io`
+
+- **Breaking change** [#46875](https://github.com/dart-lang/sdk/issues/46875):
+  The `SecurityContext` class in `dart:io` has been updated to set the minimum
+  TLS protocol version to TLS1_2_VERSION (1.2) instead of TLS1_VERSION.
+- Add `RawSocket.sendMessage`, `RawSocket.receiveMessage` that allow passing of
+  file handle references via Unix domain sockets.
+
+#### `dart:js_util`
+
+- The `js_util` methods `setProperty`, `callMethod`, and `callConstructor` have
+  been optimized to remove checks on arguments when the checks can be elided.
+  Also, those methods, along with `getProperty` and `newObject`, now support a
+  generic type argument to specify a return type. These two changes make simple
+  `js_util` usage, like reading and writing primitive properties or calling
+  methods with simple arguments, have zero overhead.
+
+#### `dart:web_sql`
+
+- **Breaking change** [#46316](https://github.com/dart-lang/sdk/issues/46316):
+  The WebSQL standard was abandoned more than 10
+  years ago and is not supported by many browsers. This release completely
+  deletes the `dart:web_sql` library.
+
+#### `dart:html`
+
+- **Breaking change** [#46316](https://github.com/dart-lang/sdk/issues/46316):
+  Related to the removal of `dart:web_sql` (see above), `window.openDatabase`
+  has been removed.
+
+### Tools
+
+#### Dart command line
+
+- **Breaking change** [#46100][]: The standalone `dart2native` tool has been
+  removed as previously announced. Its replacements are the
+  `dart compile exe` and `dart compile aot-snapshot` commands, which offer the
+  same functionality.
+
+- **Breaking change**: The standalone `dartfmt` tool has been removed as
+  previously announced. Its replacement is the `dart format` command.
+
+  Note that `dart format` has [a different set of options and
+  defaults][dartfmt cli] than `dartfmt`.
+
+- When a script is `dart run` it will always be precompiled, but with
+  incremental precompilation for following runs.
+
+#### Dart VM
+
+- **Breaking change** [#45451](https://github.com/dart-lang/sdk/issues/45451):
+  Support for `dart-ext:`-style native extensions has been removed as previously
+  announced. Use `dart:ffi` to bind to native libraries instead.
+
+- **Breaking change** [#46754](https://github.com/dart-lang/sdk/issues/46754):
+  Isolates spawned via the `Isolate.spawn()` API are now grouped, operate on the
+  same managed heap and can therefore share various VM-internal data structures.
+
+  This leads to ~100x faster isolate startup latency, ~10-100x lower
+  per-isolate base memory overhead and ~8x faster inter-isolate communication.
+
+  Making isolates operate on the same heap will also make them collaborate on
+  garbage collections, which changes performance characteristics for GC-heavy
+  applications that may - in rare cases - negatively affect pause times or
+  throughput.
+
+- Allow closures both in inter-isolate messages as well as as entrypoints in
+  `Isolate.spawn(<entrypoint>, ...)` calls. Closures and their enclosing context
+  may need to be copied in this process. The enclosing context is - as with
+  normal messages - verified to only contain objects that are sendable.
+
+  Note of caution: The Dart VM's current representation of enclosing variables
+  in closures can make closures hang on to more variables than strictly needed.
+  Using such closures in inter-isolate communication can therefore lead to
+  copying of larger transitive object graphs. If the extended transitive
+  closure includes objects that are illegal to send, the sending will fail.
+  See [#36983](https://github.com/dart-lang/sdk/issues/36983), which tracks this
+  existing memory leak issue.
+
+#### Linter
+
+Updated the Linter to `1.14.0`, which includes changes that
+- improves performance for `annotate_overrides`, `prefer_contains`, and
+  `prefer_void_to_null`.
+- marks `avoid_dynamic_calls` stable.
+- fixed `avoid_null_checks_in_equality_operators` false positive with
+  non-nullable params.
+- update `avoid_print` to allow `kDebugMode`-wrapped print calls.
+- adds support for constructor tear-offs to `avoid_redundant_argument_values`,
+  `unnecessary_lambdas`, and `unnecessary_parenthesis`.
+- improves messages for `avoid_renaming_method_parameters`.
+- improves regular expression parsing performance for common checks
+  (`camel_case_types`, `file_names`, etc.).
+- fixed `file_names` to report at the start of the file
+  (not the entire compilation unit).
+- allow `while (true) { ... }` in `literal_only_boolean_expressions`.
+- fixed `omit_local_variable_types` false positives.
+- fixed `omit_local_variable_types` to not flag a local type that is required
+  for inference.
+- fixed `overridden_fields` false positive with static fields.
+- fixed `prefer_collection_literals` named typed parameter false positives.
+- fixed `prefer_const_constructors` false positive for deferred imports.
+- fixed `prefer_final_parameters` handling of initializing formals.
+- fixed `prefer_generic_function_type_aliases` false positives with incomplete
+  statements.
+- fixed `prefer_initializing_formals` false positives with factory constructors.
+- fixed `prefer_void_to_null` false positive with overridden properties.
+- fixed `prefer_void_to_null` false positives on overriding returns.
+- fixed `prefer_void_to_null` false positives.
+- adds a new lint: `unnecessary_constructor_name` to flag unnecessary uses of
+  `.new`.
+- updates `unnecessary_getters_setters` to only flag the getter.
+- fixed `unnecessary_parenthesis` false positive with function expressions.
+- fixed `use_build_context_synchronously` false positive in awaits inside
+  anonymous functions.
+- improve control flow analysis for `use_build_context_synchronously`.
+- fixed `use_rethrow_when_possible` false positives.
+- fixed `void_checks` false positives with incomplete source.
+
+### Pub
+
+- If you have analytics enabled `dart pub get` will send
+  [usage metrics](https://github.com/dart-lang/pub/blob/0035a40f25d027130c0314571da53ffafc6d973b/lib/src/solver/result.dart#L131-L175)
+  for packages from pub.dev, intended for popularity analysis.
+- Adds support for token-based authorization to third-party package-repositories
+  with the new command `dart pub token`.
+- Credentials are no longer stored in the pub-cache, but in a platform dependent
+  config directory:
+  * On Linux `$XDG_CONFIG_HOME/dart/pub-credentials.json` if `$XDG_CONFIG_HOME`
+    is defined, otherwise `$HOME/.config/dart/pub-credentials.json`
+  * On Mac OS: `$HOME/Library/Application Support/dart/pub-credentials.json`
+  * On Windows: `%APPDATA%/dart/pub-credentials.json`
+- The syntax for dependencies hosted at a third-party package repository has
+  been simplified. Before you would need to write:
+
+```yaml
+dependencies:
+  colorizer:
+    hosted:
+      name: colorizer
+      url: 'https://custom-pub-server.com'
+    version: ^1.2.3
+environment:
+  sdk: '>=2.14.0 < 3.0.0'
+```
+
+Now you can write:
+
+```yaml
+dependencies:
+  colorizer:
+    hosted: 'https://custom-pub-server.com'
+    version: ^1.2.3
+environment:
+  sdk: '>=2.15.0 < 3.0.0'
+```
+
+This feature requires
+[language-version](https://dart.dev/guides/language/evolution#language-versioning)
+2.15 or later, e.g. the `pubspec.yaml` should have an SDK constraint of
+`>=2.15 <3.0.0`.
+
+- Detect potential leaks in `dart pub publish`.
+  When publishing, pub will examine your files for potential secret keys, and
+  warn you.
+
+  To ignore a file that has a false positive, add it to a
+  [`false_secrets`](https://dart.dev/go/false-secrets) section of your
+  `pubspec.yaml`.
+- Fixes unicode terminal detection windows.
+- New flag `--example` to the commands
+  `dart pub get/upgrade/downgrade/add/remove` that will result in the `example/`
+  folder dependencies to be updated after operating in the current directory.
+
+### Other libraries
+
+#### `package:js`
+
+- Extensions on JS interop or native `dart:html` classes can now declare
+  members as `external`. These members are equivalent to regular extension
+  members that use `js_util` to expose the underlying JavaScript.
+
+## 2.14.4 - 2021-10-14
+
+This is a patch release that fixes:
+
+- a memory leak of analyzer plugins (issue [flutter/flutter#90868][]).
+- the Dart VM sometimes loading expired certificates on Windows (issues
+  [#46370][] and [#47420][]).
+
+[flutter/flutter#90868]: https://github.com/flutter/flutter/issues/90868
+[#46370]: https://github.com/dart-lang/sdk/issues/46370
+[#47420]: https://github.com/dart-lang/sdk/issues/47420
+
+## 2.14.3 - 2021-09-30
+
+This is a patch release that fixes:
+
+- a code completion performance regression (issue
+  [flutter/flutter-intellij#5761][]).
+- debug information emitted by the Dart VM (issue [#47289][]).
+
+[flutter/flutter-intellij#5761]:
+  https://github.com/flutter/flutter-intellij/issues/5761
+[#47289]: https://github.com/dart-lang/sdk/issues/47289
+
+## 2.14.2 - 2021-09-16
+
+This is a patch release that fixes:
+
+- two dartdoc crashes (issues [dart-lang/dartdoc#2740][] and
+  [dart-lang/dartdoc#2755][]).
+- error messages when using the `>>>` operator on older language versions
+  (issue [#46886][]).
+- invalid `pubspec.lock` paths on Windows (issue [dart-lang/pub#3012][]).
+
+[dart-lang/dartdoc#2740]: https://github.com/dart-lang/dartdoc/issues/2740
+[dart-lang/dartdoc#2755]: https://github.com/dart-lang/dartdoc/issues/2755
+[#46886]: https://github.com/dart-lang/sdk/issues/46886
+[#45767]: https://github.com/dart-lang/sdk/issues/45767
+[dart-lang/pub#3012]: https://github.com/dart-lang/pub/issues/3012
+
+## 2.14.1 - 2021-09-09
+
+- Fixed an issue specific to the macOS ARM64 (Apple Silicon) SDK, where the Dart
+  commandline tools did not have the expected startup performance.
+
+## 2.14.0 - 2021-09-09
+
+### Language
+
+- Add an unsigned shift right operator `>>>`. Pad with zeroes, ignoring the sign
+  bit. On the web platform `int.>>>` shifts the low 32 bits interpreted as an
+  unsigned integer, so `a >>> b` gives the same result as
+  `a.toUnsigned(32) >>> b` on the VM.
+
+- Prior to Dart 2.14, metadata (annotations) were not permitted to be specified
+  with generic type arguments. This restriction is lifted in Dart 2.14.
+
+  ```dart
+  class C<T> {
+    const C();
+  }
+  @C();      // Previously permitted.
+  @C<int>(); // Previously an error, now permitted.
+  ```
+
+- Prior to Dart 2.14, generic function types were not permitted as arguments to
+  generic classes or functions, nor to be used as generic bounds. This
+  restriction is lifted in Dart 2.14.
+
+  ```dart
+  T wrapWithLogging<T>(T f) {
+    if (f is void Function<T>(T x)) {
+      return <S>(S x) {
+        print("Call: f<$S>($x)");
+        var r = f<S>(x);
+        print("Return: $x");
+        return r;
+      } as T;
+    } // More cases here
+    return f;
+  }
+  void foo<T>(T x) {
+    print("Foo!");
+  }
+  void main() {
+    // Previously an error, now permitted.
+    var f = wrapWithLogging<void Function<T>(T)>(foo);
+    f<int>(3);
+  }
+  ```
+
+### Core libraries
+
+#### `dart:async`
+
+- The uncaught error handlers of `Zone`s are now run in the parent zone of the
+  zone where they were declared. This prevents a throwing handler from causing
+  an infinite loop by repeatedly triggering itself.
+
+- Added `ignore()` as extension member on futures.
+
+- Added `void unawaited(Future)` top-level function to deal with the
+  `unawaited_futures` lint.
+
+#### `dart:core`
+
+- Introduce `Enum` interface implemented by all `enum` declarations.
+
+- The native `DateTime` class now better handles local time around daylight
+  saving changes that are not precisely one hour. (No change on the Web which
+  uses the JavaScript `Date` object.)
+
+- Adds static methods `hash`, `hashAll` and `hashAllUnordered` to the `Object`
+  class. These can be used to combine the hash codes of multiple objects in a
+  consistent way.
+
+- The `Symbol` constructor now accepts any string as argument. Symbols are equal
+  if they were created from the same string.
+
+
+#### `dart:ffi`
+
+- Add the `DynamicLibrary.providesSymbol` function to check whether a symbol is
+  available in a dynamic library.
+- Add `Union` native type for interacting with unions in native memory.
+
+#### `dart:html`
+
+- `convertNativeToDart_Dictionary()` now converts objects recursively, this
+  fixes APIs like MediaStreamTrack.getCapabilities that convert between Maps and
+  browser Dictionaries. [#44319]
+- Added some access-control HTTP header names to `HttpHeaders`.
+
+[#44319]: https://github.com/dart-lang/sdk/issues/44319
+
+#### `dart:io`
+
+- BREAKING CHANGE (for pre-migrated null safe code): `HttpClient`'s
+  `.authenticate` and `.authenticateProxy` setter callbacks must now accept a
+  nullable `realm` argument.
+- Added some access-control HTTP header names to `HttpHeaders`.
+
+#### `dart:typed_data`
+
+- **BREAKING CHANGE** (https://github.com/dart-lang/sdk/issues/45115) Most types
+  exposed by this library can no longer be extended, implemented or mixed-in.
+  The affected types are `ByteBuffer`, `TypedData` and _all_ its subclasses,
+  `Int32x4`, `Float32x4`, `Float64x2` and `Endian`.
+
+#### `dart:web_sql`
+
+- `dart:web_sql` is marked deprecated and will be removed in an upcoming
+  release. Also the API `window.openDatabase` in `dart:html` is deprecated as
+  well.
+
+  This API and library was exposing the WebSQL proposed standard. The standard
+  was abandoned more than 5 years ago and is not supported by most browsers. The
+  `dart:web_sql` library has been documented as unsupported and deprecated for
+  many years as well and but wasn't annotated properly until now.
+
+### Dart VM
+
+- **Breaking change** [#45071][]: `Dart_NewWeakPersistentHandle`'s and
+  `Dart_NewFinalizableHandle`'s `object` parameter no longer accepts `Pointer`s
+  and subtypes of `Struct`. Expandos no longer accept `Pointer`s and subtypes of
+  `Struct`s.
+
+[#45071]: https://github.com/dart-lang/sdk/issues/45071
+
+### Tools
+
+#### Dart command line
+
+- **Breaking change** [#46100][]: The standalone `dart2native` tool has been
+  marked deprecated, and now prints a warning message. Its replacements are the
+  `dart compile exe` and `dart compile aot-snapshot` commands, which offer the
+  same functionality. The `dart2native` tool will be removed from the Dart SDK
+  in Dart 2.15.
+
+- **Breaking change**: The standalone `dartfmt` tool has been marked deprecated,
+  and now prints a warning message. Instead, use `dart format`. The `dartfmt`
+  tool will be removed from the Dart SDK in Dart 2.15.
+
+  Note that `dart format` has [a different set of options and
+  defaults][dartfmt cli] than `dartfmt`.
+
+- The `dart create` command has been updated to create projects that use the new
+  'recommended' set of lints from `package:lints`. See
+  https://dart.dev/go/core-lints for more information about these lints.
+
+[#46100]: https://github.com/dart-lang/sdk/issues/46100
+[dartfmt cli]: https://github.com/dart-lang/dart_style/wiki/CLI-Changes
+
+- The `dart analyze` command has been extended to support specifying multiple
+  files or directories to analyze; see also
+  https://github.com/dart-lang/sdk/issues/45352.
+
+- The `dartanalyzer` command's JSON output mode has been changed to emit the
+  JSON output on stdout instead of stderr.
+
+#### dart format
+
+- Simplify and optimize cascade formatting. See:
+  https://github.com/dart-lang/dart_style/pull/1033
+- Don't unnecessarily split argument lists with `/* */` comments.
+- Return correct exit code from `FormatCommand` when formatting stdin.
+- Split empty catch blocks with finally clauses or catches after them.
+
+#### Linter
+
+Updated the Linter to `1.8.0`, which includes changes that
+- improve performance for `prefer_is_not_empty`.
+- fix false positives in `no_logic_in_create_state`.
+- improve `package_names` to allow dart identifiers as package names.
+- fix a false-positive in `package_names` (causing keywords to wrongly get flagged).
+- fix `avoid_classes_with_only_static_member` to check for inherited members and also
+  flag classes with only methods.
+- fix `curly_braces_in_flow_control_structures` to properly flag terminating `else-if`
+  blocks.
+- improve `always_specify_types` to support type aliases.
+- fix a false positive in `unnecessary_string_interpolations` w/ nullable interpolated
+  strings
+- fix a false positive in `avoid_function_literals_in_foreach_calls` for nullable
+  iterables.
+- fix false positives in `avoid_returning_null` w/ NNBD
+- fix false positives in `use_late_for_private_fields_and_variables` in the presence
+  of const constructors.
+- adds a new lint: `eol_at_end_of_file`.
+- fix case-sensitive false positive in `use_full_hex_values_for_flutter_colors`.
+- improve try-block and switch statement flow analysis for
+  `use_build_context_synchronously`.
+- update `use_setters_to_change_properties` to only highlight a method name, not
+  the entire body and doc comment.
+- update `unnecessary_getters_setters` to allow otherwise "unnecessary" getters
+  and setters with annotations.
+- update `missing_whitespace_between_adjacent_strings` to allow String
+  interpolations at the beginning and end of String literals.
+- update `unnecessary_getters_setters` to allow for setters with non-basic
+  assignments (for example, `??=` or `+=`).
+- relax `non_constant_identifier_names` to allow for a trailing underscore.
+- fix false negative in `prefer_final_parameters` where first parameter is
+  final.
+- improve `directives_ordering` sorting of directives with dot paths and
+  dot-separated package names.
+- (internal) migrate to `SecurityLintCode` instead of deprecated
+  `SecurityLintCodeWithUniqueName`.
+- (internal) fix `avoid_types_as_parameter_names` to skip field formal
+  parameters.
+- fix false positives in `prefer_interpolation_to_compose_strings` where the
+  left operand is not a String.
+- fix false positives in `only_throw_errors` for misidentified type variables.
+- add new lint: `depend_on_referenced_packages`.
+- update `avoid_returning_null_for_future` to skip checks for null-safe
+  libraries.
+- add new lint: `use_test_throws_matchers`.
+- relax `sort_child_properties_last` to accept closures after child.
+- improve performance for `prefer_contains` and `prefer_is_empty`.
+- add new lint: `noop_primitive_operations`.
+- mark `avoid_web_libraries_in_flutter` as stable.
+- add new lint: `prefer_final_parameters`.
+- update `prefer_initializing_formals` to allow assignments where identifier
+  names don't match.
+- update `directives_ordering` to checks ordering of `package:` imports in code
+  outside pub packages.
+- add simple reachability analysis to `use_build_context_synchronously` to
+  short-circuit await-discovery in terminating blocks.
+- update `use_build_context_synchronously` to recognize nullable types when
+  accessed from legacy libraries.
+
+#### Pub
+
+- `dart pub publish` now respects `.pubignore` files with gitignore-style rules.
+  `.gitignore` files in the repo are still respected if they are not overridden
+  by a `.pubignore` in the same directory.
+
+  pub no longer queries git for listing the files. This implies:
+
+  - Checked in files will now be ignored if they are included by a `.gitignore`
+    rule.
+  - Global ignores are no longer taken into account.
+  - Even packages that are not in git source control will have their
+    `.gitignore` files respected.
+  - `.gitignore` and `.pubignore` is always case-insensitive on MacOs and
+    Windows (as is default for `git` repositories).
+
+- New flag `dart pub deps --json` gives a machine parsable overview of the
+  current dependencies.
+- New command: `dart pub cache clean`. Will delete everything in your current
+  pub cache.
+- Commands related to a single package now takes a `--directory` option to
+  operate on a package in the given directory instead of the working directory.
+- git dependencies with a relative repo url would previously be interpreted
+  relative to the current package, even for transitive dependencies. This now
+  fails instead.
+
+- Pub now uses a Dart library to read and write tar files. This should fix
+  several issues we had with incompatibilities between different system `tar`s.
+- `PUB_HOSTED_URL` can now include a trailing slash.
+- Incremental compilation is now used for compilation of executables from
+  dependencies when using `dart run <package>:<command>`.
+
+#### Dart2JS
+
+*   **Breaking change** [#46545][]: Dart2JS emits ES6+ JavaScript by default,
+    thereby no longer supporting legacy browsers. Passing the
+    `--legacy-javascript` flag will let you opt out of this update, but this
+    flag will be removed in a future release. Modern browsers will not be
+    affected, as Dart2JS continues to support [last two major releases][1] of
+    Edge, Safari, Firefox, and Chrome.
+
+[#46545]: https://github.com/dart-lang/sdk/issues/46545
+[1]: https://dart.dev/faq#q-what-browsers-do-you-support-as-javascript-compilation-targets
+
+#### Dart Dev Compiler (DDC)
+
+- **Breaking change** [#44154][]: Subtyping relations of `package:js` classes
+  have been changed to be more correct and consistent with Dart2JS.
+  Like `anonymous` classes, non-`anonymous` classes will no longer check the
+  underlying type in DDC. The internal type representation of these objects have
+  changed as well, which will affect the `toString` value of these types.
+
+[#44154]: https://github.com/dart-lang/sdk/issues/44154
+
+## 2.13.4 - 2021-06-28
+
+This is a patch release that fixes:
+
+- a Dart VM compiler crash (issue [flutter/flutter#84212][]).
+- a DDC compiler crash (issue [flutter/flutter#82838][]).
+
+[flutter/flutter#84212]: https://github.com/flutter/flutter/issues/84212
+[flutter/flutter#82838]: https://github.com/flutter/flutter/issues/82838
+
+## 2.13.3 - 2021-06-10
+
+This is a patch release that fixes:
+
+- a Dart compiler crash (issue [flutter/flutter#83094][]).
+- an analysis server deadlock causing it to stop responding to IDE requests
+  (issue [#45996][]).
+- an analyzer crash when analyzing against `package:meta` `v1.4.0` (issue
+  [#46183][]).
+
+[flutter/flutter#83094]: https://github.com/flutter/flutter/issues/83094
+[#45996]: https://github.com/dart-lang/sdk/issues/45996
+[#46183]: https://github.com/dart-lang/sdk/issues/46183
+
+## 2.13.1 - 2021-05-25
+
+This is a patch release that fixes:
+
+- incorrect behavior in CastMap (issue [#45473][]).
+- missing nullability from recursive type hierarchies in DDC (issue [#45767][]).
+
+[#45473]: https://github.com/dart-lang/sdk/issues/45473
+[#45767]: https://github.com/dart-lang/sdk/issues/45767
+
+## 2.13.0 - 2021-05-18
+
+### Language
+
+- **Type aliases** [Non-function type aliases][]: Type aliases (names for types
+  introduced via the `typedef` keyword) were previously restricted to only
+  introduce names for function types. In this release, we remove this
+  restriction and allow type aliases to name any kind of type.
+
+  ```dart
+  import 'dart:convert';
+
+  typedef JsonMap = Map<String, dynamic>;
+
+  JsonMap parseJsonMap(String input) => json.decode(input) as JsonMap;
+  ```
+
+  In addition to being usable as type annotations, type aliases that name class
+  types can now also be used anywhere that the underlying class could be used,
+  allowing type aliases to be used to safely rename existing classes.
+
+  ```dart
+  class NewClassName<T> {
+     NewClassName.create(T x);
+     static NewClassName<T> mkOne<T>(T x) => NewClassName<T>.create(x);
+   }
+  @Deprecated("Use NewClassName instead")
+  typedef OldClassName<T> = NewClassName<T>;
+
+  class LegacyClass extends OldClassName<int> {
+    LegacyClass() : super.create(3);
+  }
+  OldClassName<int> legacyCode() {
+    var one = OldClassName.create(1);
+    var two = OldClassName.mkOne(2);
+    return LegacyClass();
+  }
+  ```
+
+  The new type alias feature is only available as part of the 2.13
+  [language version](https://dart.dev/guides/language/evolution). To use this
+  feature, you must set the lower bound on the sdk constraint for your package
+  to 2.13 or greater.
+
+  [non-function type aliases]:
+    https://github.com/dart-lang/language/blob/master/accepted/2.13/nonfunction-type-aliases/feature-specification.md
+
+### Core libraries
+
+#### `dart:collection`
+
+- The `SplayTreeMap` was changed to allow `null` as key if the `compare`
+  function allows it. It now checks that a new key can be used as an argument to
+  the `compare` function when the member is added, _even if the map is empty_
+  (in which case it just compares the key to itself).
+
+- The `SplayTreeSet` was changed to checks that a new element can be used as an
+  argument to the `compare` function when the member is added, _even if the set
+  is empty_ (in which case it just compares the element to itself).
+
+#### `dart:developer`
+
+- Added `serverWebSocketUri` property to `ServiceProtocolInfo`.
+
+#### `dart:ffi`
+
+- Add `Packed` for interacting with packed structs in native memory.
+- Add `Array` for interacting with structs with inline arrays.
+
+### Dart VM
+
+### Tools
+
+#### Analyzer
+
+- Static analyses with "error" severity can once again be ignored with comments
+  like `// ignore: code` and `// ignore_for_file: code`. To declare that certain
+  analysis codes, or codes with certain severities ("error", "warning", and
+  "info") cannot be ignored with such comments, list them in
+  `analysis_options.yaml`, under the `analyzer` heading, with a new YAML key,
+  `cannot-ignore`. For example, to declare that "error" codes and
+  `unused_import` cannot be ignored, write the following into
+  `analysis_options.yaml`:
+
+  ```yaml
+  analyzer:
+    cannot-ignore:
+      - error
+      - unused_import
+  ```
+
+#### dart format
+
+- Correct constructor initializer indentation after `required` named parameters.
+
+#### Linter
+
+Updated the Linter to `1.2.1`, which includes:
+
+- Improved `iterable_contains_unrelated_type` to better support `List` content
+  checks.
+- Fixed `camel_case_types` and `prefer_mixin` to support non-function type
+  aliases.
+- Fixed `prefer_mixin` to properly make exceptions for `dart.collection` legacy
+  mixins.
+- Added new lints `avoid_multiple_declarations_per_line`,
+  `use_if_null_to_convert_nulls_to_bools`, `deprecated_consistency`,
+  `use_named_constants`, `use_build_context_synchronously` (experimental).
+- Deprecated `avoid_as`.
+- Migrated library to null-safety.
+
+### Other libraries
+
+#### `package:js`
+
+- **Breaking change:** It is no longer valid to use `String`s that match an
+  `@Native` annotation in an `@JS()` annotation for a non-anonymous JS interop
+  class. This led to erroneous behavior due to the way interceptors work. If you
+  need to work with a native class, prefer `dart:html`, an `@anonymous` class,
+  or `js_util`. See issue [#44211][] for more details.
+
+[#44211]: https://github.com/dart-lang/sdk/issues/44211
+
+## 2.12.4 - 2021-04-15
+
+This is a patch release that fixes a Dart VM compiler crashes when compiling
+initializers containing async closures (issue [#45306][]).
+
+[#45306]: https://github.com/dart-lang/sdk/issues/45306
+
+## 2.12.3 - 2021-04-14
+
+**Security advisory**: This is a patch release that fixes a vulnerability in
+`dart:html` related to DOM clobbering. See the security advisory
+[CVE-2021-22540][cve-2021-22540] for more details. Thanks again to **Vincenzo di
+Cicco** for finding and reporting this vulnerability.
+
+[cve-2021-22540]:
+  https://github.com/dart-lang/sdk/security/advisories/GHSA-3rfv-4jvg-9522
+
+## 2.12.2 - 2021-03-17
+
+This is a patch release that fixes crashes reported by Flutter 2 users (issue
+[flutter/flutter#78167][]).
+
+[flutter/flutter#78167]: https://github.com/flutter/flutter/issues/78167
+
+## 2.12.1 - 2021-03-10
+
+This is a patch release that fixes:
+
+- an unhandled exception in HTTPS connections (issue [#45047][]).
+- a typing issue in the typed_data `+` operator (issue [#45140][]).
+
+[#45047]: https://github.com/dart-lang/sdk/issues/45047
+[#45140]: https://github.com/dart-lang/sdk/issues/45140
+
+## 2.12.0 - 2021-03-03
+
+### Language
+
+- **Breaking change** [Null safety][] is now enabled by default in all code that
+  has not opted out. With null safety, types in your code are non-nullable by
+  default. Null can only flow into parts of your program where you want it. With
+  null safety, your runtime null-dereference bugs turn into edit-time analysis
+  errors.
+
+  You can opt out of null safety and preserve your code's previous behavior by
+  setting the lower bound of the SDK constraint in your pubspec to 2.11.0 or
+  earlier to request an earlier [language version][]. You can opt out individual
+  Dart files by adding `// @dart=2.11` to the beginning of the file.
+
+  Files that are opted in to null safety may report new compile-time errors.
+  Opting in to null safety also gives you access to other new language features:
+
+  - Smarter flow analysis and type promotion
+  - `required` named parameters
+  - `late` variables
+  - The postfix `!` null assertion operator
+  - The `?..` and `?[]` null-aware operators
+
+- **Breaking change** [#44660][]: Fixed an implementation bug where `this` would
+  sometimes undergo type promotion in extensions.
+
+[null safety]: https://dart.dev/null-safety/understanding-null-safety
+[language version]:
+  https://dart.dev/guides/language/evolution#language-versioning
+[#44660]: https://github.com/dart-lang/sdk/issues/44660
+
+### Core libraries
+
+#### `dart:async`
+
+- Add extension method `onError()` on `Future` to allow better typing of error
+  callbacks.
+
+#### `dart:collection`
+
+- Add `UnmodifiableSetView` class, which allows users to guarantee that methods
+  that could change underlying `Set` instance can not be invoked.
+
+- Make it explicit that `LinkedList` compares elements by identity, and update
+  `contains()` to take advantage of this.
+
+#### `dart:core`
+
+- Add `Set.unmodifiable()` constructor, which allows users to create
+  unmodifiable `Set` instances.
+
+#### `dart:ffi`
+
+- **Breaking change** [#44621][]: Invocations with a generic `T` of `sizeOf<T>`,
+  `Pointer<T>.elementAt()`, `Pointer<T extends Struct>.ref`, and
+  `Pointer<T extends Struct>[]` are being deprecated in the current stable
+  release (2.12), and are planned to be fully removed in the following stable
+  release (2.13). Consequently, `allocate` in `package:ffi` will no longer be
+  able to invoke `sizeOf<T>` generically, and will be deprecated as well.
+  Instead, the `Allocator` it is introduced to `dart:ffi`, and also requires a
+  constant `T` on invocations. For migration notes see the breaking change
+  request.
+
+- **Breaking change** [#44622][]: Subtypes of `Struct` without any native member
+  are being deprecated in the current stable release (2.12), and are planned to
+  be fully removed in the following stable release (2.13). Migrate opaque types
+  to extend `Opaque` rather than `Struct`.
+
+[#44621]: https://github.com/dart-lang/sdk/issues/44621
+[#44622]: https://github.com/dart-lang/sdk/issues/44622
+
+#### `dart:io`
+
+- `HttpRequest` now correctly follows HTTP 308 redirects
+  (`HttpStatus.permanentRedirect`).
+
+#### `dart:isolate`
+
+- Add `debugName` positional parameter to `ReceivePort` and `RawReceivePort`
+  constructors, a name which can be associated with the port and displayed in
+  tooling.
+- Introduce `Isolate.exit([port, message])` which terminates current isolate
+  and, if `port` is specified, as a last action sends out the `message` out to
+  that `port`.
+
+#### `dart:html`
+
+- `EventStreamSubscription.cancel` has been updated to retain its synchronous
+  timing when running in both sound and unsound null safety modes. See issue
+  [#44157][] for more details.
+
+[#44157]: https://github.com/dart-lang/sdk/issues/44157
+
+### Dart VM
+
+- **Breaking change** [#42312][]: `Dart_WeakPersistentHandle`s no longer
+  auto-delete themselves when the referenced object is garbage collected to
+  avoid race conditions, but they are still automatically deleted when the
+  isolate group shuts down.
+
+- **Breaking change** [#42312][]: `Dart_WeakPersistentHandleFinalizer` is
+  renamed to `Dart_HandleFinalizer` and had its `handle` argument removed. All
+  API functions using that type have been updated.
+
+[#42312]: https://github.com/dart-lang/sdk/issues/42312
+
+### Dart2JS
+
+- Remove `--no-defer-class-types` and `--no-new-deferred-split`.
+
+### Tools
+
+#### Analyzer
+
+- Remove the `--use-fasta-parser`, `--preview-dart-2`, and
+  `--enable-assert-initializers` command line options. These options haven't
+  been supported in a while and were no-ops.
+
+- Report diagnostics regarding the
+  [`@internal`](https://pub.dev/documentation/meta/latest/meta/internal-constant.html)
+  annotation.
+
+- Improve diagnostic-reporting regarding the
+  [`@doNotStore`](https://pub.dev/documentation/meta/latest/meta/doNotStore-constant.html)
+  annotation.
+
+- Introduce a diagnostic which is reported when a library member named `main` is
+  not a function.
+
+- Introduce a diagnostic which is reported when a `main` function's first
+  parameter is not a supertype of `List<String>`.
+
+- Introduce diagnostics for when an `// ignore` comment contains an error code
+  which is not being reported, cannot be ignored, or is already being ignored.
+
+- Report diagnostics when using
+  [`@visibleForTesting`](https://pub.dev/documentation/meta/latest/meta/
+  visibleForTesting-constant.html) on top-level variables.
+
+- Fix false positive reports of "unused element" for top-level setters and
+  getters.
+
+- Fix false positive reports regarding `@deprecated` field formal parameters at
+  their declaration.
+
+- For null safety, introduce a diagnostic which reports when a null-check will
+  always fail.
+
+- Fix false positive reports regarding optional parameters on private
+  constructors being unused.
+
+- Introduce a diagnostic which is reported when a constructor includes duplicate
+  field formal parameters.
+
+- Improve the "unused import" diagnostic when multiple import directives share a
+  common prefix.
+
+- Fix false positive "unused import" diagnostic regarding an import which
+  provides an extension method which is used.
+
+- For null safety, improve the messaging of "use of nullable value" diagnostics
+  for eight different contexts.
+
+- Fix false positive reports regarding `@visibleForTesting` members in a "hide"
+  combinator of an import or export directive.
+
+- Improve the messaging of "invalid override" diagnostics.
+
+- Introduce a diagnostic which is reported when `Future<T>.catchError` is called
+  with an `onError` callback which does not return `FutureOr<T>`.
+
+#### dartfmt
+
+- Don't duplicate comments on chained if elements.
+
+- Preserve `?` in initializing formal function-typed parameters.
+
+- Fix performance issue with constructors that have no initializer list.
+
+#### Linter
+
+Updated the Linter to `0.1.129`, which includes:
+
+- New lints: `avoid_dynamic_calls`, `cast_nullable_to_non_nullable`,
+  `null_check_on_nullable_type_parameter`,
+  `tighten_type_of_initializing_formals`, `unnecessary_null_checks`, and
+  `avoid_type_to_string`.
+
+- Fix crash in `prefer_collection_literals` when there is no static parameter
+  element.
+
+- Fix false negatives for `prefer_collection_literals` when a LinkedHashSet or
+  LinkedHashMap instantiation is passed as the argument to a function in any
+  position other than the first.
+
+- Fix false negatives for `prefer_collection_literals` when a LinkedHashSet or
+  LinkedHashMap instantiation is used in a place with a static type other than
+  Set or Map.
+
+- Update to `package_names` to allow leading underscores.
+
+- Fix crashes in `unnecessary_null_checks` and
+  `missing_whitespace_between_adjacent_strings`.
+
+- Update to `void_checks` for null safety.
+
+- Fix range error in `unnecessary_string_escapes`.
+
+- Fix false positives in `unnecessary_null_types`.
+
+- Fix to `prefer_constructors_over_static_methods` to respect type parameters.
+
+- Update to `always_require_non_null_named_parameters` to be null safety-aware.
+
+- Update to `unnecessary_nullable_for_final_variable_declarations` to allow
+  dynamic.
+
+- Update `overridden_fields` to not report on abstract parent fields.
+
+- Fix to `unrelated_type_equality_checks` for null safety.
+
+- Improvements to `type_init_formals`to allow types not equal to the field type.
+
+- Updates to `public_member_apis` to check generic type aliases.
+
+- Fix `close_sinks` to handle `this`-prefixed property accesses.
+
+- Fix `unawaited_futures` to handle `Future` subtypes.
+
+- Performance improvements to `always_use_package_imports`,
+  `avoid_renaming_method_parameters`, `prefer_relative_imports` and
+  `public_member_api_docs`.
+
+#### Pub
+
+- **Breaking**: The Dart SDK constraint is now **required** in `pubspec.yaml`.
+  You must include a section like:
+
+  ```yaml
+  environment:
+    sdk: ">=2.10.0 <3.0.0"
+  ```
+
+  See [#44072][].
+
+  For legacy dependencies without an SDK constraint, pub will now assume a
+  default language version of 2.7.
+
+- The top level `pub` executable has been deprecated. Use `dart pub` instead.
+  See [dart tool][].
+
+- New command `dart pub add` that adds new dependencies to your `pubspec.yaml`,
+  and a corresponding `dart pub remove` that removes dependencies.
+
+- New option `dart pub upgrade --major-versions` will update constraints in your
+  `pubspec.yaml` to match the _resolvable_ column reported in
+  `dart pub outdated`. This allows users to easily upgrade to latest version for
+  all dependencies where this is possible, even if such upgrade requires an
+  update to the version constraint in `pubspec.yaml`.
+
+  It is also possible to only upgrade the major version for a subset of your
+  dependencies using `dart pub upgrade --major-versions <dependencies...>`.
+
+- New option `dart pub upgrade --null-safety` will attempt to update constraints
+  in your `pubspec.yaml`, such that only null-safety migrated versions of
+  dependencies are allowed.
+
+- New option `dart pub outdated --mode=null-safety` that will analyze your
+  dependencies for null-safety.
+
+- `dart pub get` and `dart pub upgrade` will highlight dependencies that have
+  been [discontinued](https://dart.dev/tools/pub/publishing#discontinue) on
+  pub.dev.
+
+- `dart pub publish` will now check your pubspec keys for likely typos.
+
+- `dart pub upgrade package_foo` fetchs dependencies but ignores the
+  `pubspec.lock` for `package_foo`, allowing users to only upgrade a subset of
+  dependencies.
+
+- New command `dart pub login` that logs into pub.dev.
+
+- The `--server` option to `dart pub publish` and `dart pub uploader` are
+  deprecated. Use `publish_to` in your `pubspec.yaml` or set the
+  `$PUB_HOSTED_URL` environment variable.
+
+- `pub global activate` no longer re-precompiles if the current global
+  installation was same version.
+
+- The Flutter SDK constraint upper bound is now ignored in pubspecs and
+  deprecated when publishing. See: [flutter-upper-bound-deprecation][].
+
+[flutter-upper-bound-deprecation]:
+  https://dart.dev/go/flutter-upper-bound-deprecation
+[#44072]: https://github.com/dart-lang/sdk/issues/44072
+[dart tool]: https://dart.dev/tools/dart-tool
+
+## 2.10.5 - 2021-01-21
+
+This is a patch release that fixes a crash in the Dart VM. (issue [#44563][]).
+
+[#44563]: https://github.com/dart-lang/sdk/issues/44563
+
+## 2.10.4 - 2020-11-12
+
+This is a patch release that fixes a crash in the Dart VM (issues [#43941][],
+[flutter/flutter#43620][], and [Dart-Code/Dart-Code#2814][]).
+
+[#43941]: https://github.com/dart-lang/sdk/issues/43941
+[flutter/flutter#43620]: https://github.com/flutter/flutter/issues/43620
+[dart-code/dart-code#2814]: https://github.com/Dart-Code/Dart-Code/issues/2814
+
+## 2.10.3 - 2020-10-29
+
+This is a patch release that fixes the following issues:
+
+- breaking changes in Chrome 86 that affect DDC (issues [#43750][] and
+  [#43193][]).
+- compiler error causing incorrect use of positional parameters when named
+  parameters should be used instead (issues [flutter/flutter#65324][] and
+  [flutter/flutter#68092][]).
+- crashes and/or undefined behavior in AOT compiled code (issues [#43770][] and
+  [#43786][]).
+- AOT compilation of classes with more than 64 unboxed fields (issue
+  [flutter/flutter#67803][]).
+
+[#43750]: https://github.com/dart-lang/sdk/issues/43750
+[#43193]: https://github.com/dart-lang/sdk/issues/43193
+[flutter/flutter#65324]: https://github.com/flutter/flutter/issues/65324
+[flutter/flutter#68092]: https://github.com/flutter/flutter/issues/68092
+[#43770]: https://github.com/dart-lang/sdk/issues/43770
+[#43786]: https://github.com/dart-lang/sdk/issues/43786
+[flutter/flutter#67803]: https://github.com/flutter/flutter/issues/67803
+
+## 2.10.2 - 2020-10-15
+
+This is a patch release that fixes a DDC compiler crash (issue [#43589]).
+
+[#43589]: https://github.com/dart-lang/sdk/issues/43589
+
+## 2.10.1 - 2020-10-06
+
+This is a patch release that fixes the following issues:
+
+- crashes when developing Flutter applications (issue [#43464][]).
+- non-deterministic incorrect program behaviour and/or crashes (issue
+  [flutter/flutter#66672][]).
+- uncaught TypeErrors in DDC (issue [#43661][]).
+
+[#43464]: https://github.com/dart-lang/sdk/issues/43464
+[flutter/flutter#66672]: https://github.com/flutter/flutter/issues/66672
+[#43661]: https://github.com/dart-lang/sdk/issues/43661
+
+## 2.10.0 - 2020-09-28
+
+### Core libraries
+
+#### `dart:io`
+
+- Adds `Abort` method to class `HttpClientRequest`, which allows users to cancel
+  outgoing HTTP requests and stop following IO operations.
+- A validation check is added to `path` of class `Cookie`. Having characters
+  ranging from 0x00 to 0x1f and 0x3b (";") will lead to a `FormatException`.
+- The `HttpClient` and `HttpServer` classes now have a 1 MiB limit for the total
+  size of the HTTP headers when parsing a request or response, instead of the
+  former 8 KiB limit for each header name and value. This limit cannot be
+  configured at this time.
+
+#### `dart:typed_data`
+
+- Class `BytesBuilder` is moved from `dart:io` to `dart:typed_data`. It's
+  temporarily being exported from `dart:io` as well.
+
+### `dart:uri`
+
+- [#42564]: Solved inconsistency in `Uri.https` and `Uri.http` constructors'
+  `queryParams` type.
+
+### Dart VM
+
+- **Breaking change** [#42982][]: `dart_api_dl.cc` is renamed to `dart_api_dl.c`
+  and changed to a pure C file.
+- Introduces `Dart_FinalizableHandle`s. They do auto-delete, and the weakly
+  referred object cannot be accessed through them.
+
+### Dart2JS
+
+- Adds support for deferred loading of types separately from classes. This
+  enables dart2js to make better optimization choices when deferred loading.
+  This work is necessary to address unsoundness in the deferred loading
+  algorithm. Currently, fixing this unsoundness would result in code bloat, but
+  loading types separately from classes will allow us to fix the unsoundness
+  with only a minimal regression. To explicitly disable deferred loading of
+  types, pass `--no-defer-class-types`. See the original post on the
+  [unsoundness in the deferred loading algorithm][].
+- Enables a new sound deferred splitting algorithm. To explicitly disable the
+  new deferred splitting algorithm, pass `--no-new-deferred-split`. See the
+  original post on the [unsoundness in the deferred loading algorithm][].
+
+[#42982]: https://github.com/dart-lang/sdk/issues/42982
+[unsoundness in the deferred loading algorithm]:
+  https://github.com/dart-lang/sdk/blob/302ad7ab2cd2de936254850550aad128ae76bbb7/CHANGELOG.md#dart2js-3
+
+### Tools
+
+#### dartfmt
+
+- Don't crash when non-ASCII whitespace is trimmed.
+- Split all conditional expressions (`?:`) when they are nested.
+- Handle `external` and `abstract` fields and variables.
+
+#### Linter
+
+Updated the Linter to `0.1.118`, which includes:
+
+- New lint: `unnecessary_nullable_for_final_variable_declarations`.
+- Fixed NPE in `prefer_asserts_in_initializer_lists`.
+- Fixed range error in `unnecessary_string_escapes`.
+- `unsafe_html` updated to support unique error codes.
+- Updates to `diagnostic_describe_all_properties` to check for `Diagnosticable`s
+  (not `DiagnosticableMixin`s).
+- New lint: `use_late`.
+- Fixed `unnecessary_lambdas` to respect deferred imports.
+- Updated `public_member_api_docs` to check mixins.
+- Updated `unnecessary_statements` to skip `as` expressions.
+- Fixed `prefer_relative_imports` to work with path dependencies.
+
+#### Pub
+
+- `pub run` and `pub global run` accepts a `--(no-)-sound-null-safety` flag,
+  that is passed to the VM.
+- Fix: Avoid multiple recompilation of binaries in global packages.
+- Fix: Avoid exponential behaviour of error reporting from the solver.
+- Fix: Refresh binstubs after recompile in global run.
+
+## 2.9.3 - 2020-09-08
+
+This is a patch release that fixes DDC to handle a breaking change in Chrome
+(issue [#43193][]).
+
+[#43193]: https://github.com/dart-lang/sdk/issues/43193
+
+## 2.9.2 - 2020-08-26
+
+This is a patch release that fixes transient StackOverflow exceptions when
+building Flutter applications (issue [flutter/flutter#63560][]).
+
+[flutter/flutter#63560]: https://github.com/flutter/flutter/issues/63560
+
+## 2.9.1 - 2020-08-12
+
+This is a patch release that fixes unhandled exceptions in some Flutter
+applications (issue [flutter/flutter#63038][]).
+
+[flutter/flutter#63038]: https://github.com/flutter/flutter/issues/63038
+
+## 2.9.0 - 2020-08-05
+
+### Language
+
+### Core libraries
+
+#### `dart:async`
+
+- Adds `Stream.multi` constructor creating streams which can be listened to more
+  than once, and where each individual listener can be controlled independently.
+
+#### `dart:convert`
+
+- **Breaking change** [#41100][]: When encoding a string containing unpaired
+  surrogates as UTF-8, the unpaired surrogates will be encoded as replacement
+  characters (`U+FFFD`). When decoding UTF-8, encoded surrogates will be treated
+  as malformed input. When decoding UTF-8 with `allowMalformed: true`, the
+  number of replacement characters emitted for malformed input sequences has
+  been changed to match the [WHATWG encoding standard][].
+
+[#41100]: https://github.com/dart-lang/sdk/issues/41100
+[whatwg encoding standard]: https://encoding.spec.whatwg.org/#utf-8-decoder
+
+#### `dart:io`
+
+- [#42006][]: The signature of `exit` has been changed to return the `Never`type
+  instead of `void`. since no code will run after it,
+- Class `OSError` now implements `Exception`. This change means `OSError` will
+  now be caught in catch clauses catching `Exception`s.
+- Added `InternetAddress.tryParse`.
+- [Abstract Unix Domain Socket][] is supported on Linux/Android now. Using an
+  `InternetAddress` with `address` starting with '@' and type being
+  `InternetAddressType.Unix` will create an abstract Unix Domain Socket.
+- On Windows, file APIs can now handle files and directories identified by long
+  paths (greater than 260 characters). It complies with all restrictions from
+  [Long Path on Windows][]. Note that `Directory.current` does not work with
+  long path.
+
+[#42006]: https://github.com/dart-lang/sdk/issues/42006
+[abstract unix domain socket]: http://man7.org/linux/man-pages/man7/unix.7.html
+[long path on windows]:
+  https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#maximum-path-length-limitation
+
+#### `dart:html`
+
+- **Breaking change**: `CssClassSet.add()` previously returned `null` if the
+  `CssClassSet` corresponded to multiple elements. In order to align with the
+  null-safe changes in the `Set` interface, it will now return `false` instead.
+  The same applies for `CssClassSet.toggle`.
+
+- `EventStreamSubscription.cancel` method used to return `null`, but since
+  `StreamSubscription.cancel` has changed to be non-nullable, this method
+  returns an empty `Future` instead. Due to an optimization on `null` `Future`s,
+  this method used to complete synchronously, but now that the `Future` is empty
+  instead, it completes asynchronously, therefore potentially invalidating code
+  that relied on the synchronous side-effect. This change will only affect code
+  using sound null-safety. See issue [#41653][] for more details.
+
+- Methods in `Console` have been updated to better reflect the modern Console
+  specification. Particularly of interest are `dir` and `table` which take in
+  extra optional arguments.
+
+[#41653]: https://github.com/dart-lang/sdk/issues/41653
+
+#### `dart:mirrors`
+
+- **Breaking change** [#42714][]: web compilers (dart2js and DDC) now produce a
+  compile-time error if `dart:mirrors` is imported.
+
+  Most projects should not be affected. Since 2.0.0 this library was unsupported
+  and produced runtime errors on all its APIs. Since then several tools already
+  reject code that use `dart:mirrors` including webdev and flutter tools, we
+  expect few projects to run into this problem.
+
+[#42714]: https://github.com/dart-lang/sdk/issues/42714
+
+### Tools
+
+#### dartfmt
+
+- Add `--fix-single-cascade-statements`.
+- Correctly handle `var` in `--fix-function-typedefs`.
+- Preserve leading indentation in fixed doc comments.
+- Split outer nested control flow elements.
+- Always place a blank line after script tags.
+- Don't add unneeded splits on if elements near comments.
+- Indent blocks in initializers of multiple-variable declarations.
+- Update the null-aware subscript syntax from `?.[]` to `?[]`.
+
+#### Analyzer
+
+- Static analyses with a severity of "error" can no longer be ignored with
+  comments (`// ignore: code` and `// ignore_for_file: code`).
+
+#### Linter
+
+Updated the Linter to `0.1.117`, which includes:
+
+- New lint: `do_not_use_environment`.
+- New lint: `exhaustive_cases`.
+- New lint: `no_default_cases` (experimental).
+- New lint: `sized_box_for_whitespace`.
+- New lint: `use_is_even_rather_than_modulo`.
+- Updated `directives_ordering` to remove third party package special-casing.
+- Updated `prefer_is_empty` to special-case assert initializers and const
+  contexts.
+- Updated `prefer_mixin` to allow "legacy" SDK abstract class mixins.
+- Updated `sized_box_for_whitespace` to address false-positives.
+- Updated `type_annotate_public_apis` to allow inferred types in final field
+  assignments.
+- Updated `unnecessary_lambdas` to check for tear-off assignability.
+- Updated `unsafe_html` to use a `SecurityLintCode` (making it un-ignorable) and
+  to include `Window.open`, `Element.html` and `DocumentFragment.html` in unsafe
+  API checks. Also added checks for attributes and methods on extensions.
+
+### Dart VM
+
+- **Breaking change** [#41100][]: When printing a string using the `print`
+  function, the default implementation (used when not overridden by the embedder
+  or the current zone) will print any unpaired surrogates in the string as
+  replacement characters (`U+FFFD`). Similarly, the `Dart_StringToUTF8` function
+  in the Dart API will convert unpaired surrogates into replacement characters.
+
+### Pub
+
+- `pub run` and `pub global run` accepts a `--enable-experiment` flag enabling
+  experiments in the Dart VM (and language).
+- Warn when publishing the first null-safe version of a package.
+- `pub outdated`:
+  - If the current version of a dependency is a prerelease version, use
+    prereleases for latest if there is no newer stable.
+  - Don't require a `pubspec.lock` file. When the lockfile is missing, the
+    **Current** column is empty.
+- `pub upgrade`: Show summary count of outdated packages after running. It will
+  also only show newer packages if they are not prereleases or the package is
+  already a prerelease.
+- Publishing Flutter plugins using the old plugin format is no longer allowed.
+  Plugins using the old plugin format can still be consumed.
+- `pub run`: Fix precompilation with relative `PUB_CACHE` paths
+  ([#2486](https://github.com/dart-lang/pub/pull/2486)).
+- Preserve Windows line endings in `pubspec.lock` if they are already there
+  ([#2489](https://github.com/dart-lang/pub/pull/2489)).
+- Better terminal color-detection. Use colors in terminals on Windows.
+- Fix git folder names in cache, allowing for ssh-style git dependencies.
+- Fix: Avoid precompilation of dependencies of global packages.
+
+## 2.8.4 - 2020-06-04
+
+This is a patch release that fixes potential memory leaks in the Dart front-end
+(issues [#42111][] and [#42112][]).
+
+[#42111]: https://github.com/dart-lang/sdk/issues/42111
+[#42112]: https://github.com/dart-lang/sdk/issues/42112
+
+## 2.8.3 - 2020-05-28
+
+This is a patch release that fixes the following issues:
+
+- crashes in Flutter apps (issue [flutter/flutter#57318][]).
+- a regression in stack traces (issue [#41907][]).
+- re-canonicalization of constants with unboxed fields (issue
+  [flutter/flutter#57190][]).
+
+[flutter/flutter#57318]: https://github.com/flutter/flutter/issues/57318
+[#41907]: https://github.com/dart-lang/sdk/issues/41907
+[flutter/flutter#57190]: https://github.com/flutter/flutter/issues/57190
+
+## 2.8.2 - 2020-05-13
+
+This is a patch release that fixes an AOT compilation bug in global
+transformations which manifests as a NoSuchMethod exception (issue
+[flutter/flutter#56479][]).
+
+[flutter/flutter#56479]: https://github.com/flutter/flutter/issues/56479
+
+## 2.8.1 - 2020-05-06
+
+Much of the changes in this release are in preparation for non-nullable types,
+which will arrive in a future version. In anticipation of that, we have made a
+number of small but technically breaking changes to several core library APIs in
+order to make them easier to use in a world with non-nullable types. Almost all
+existing Dart code will be unaffected by these changes, but if you see
+unexpected failures, note the breaking changes listed below.
+
+### Language
+
+There are no new language features in this release. There are only two minor
+breaking changes:
+
+- **Breaking change** [#40675][]: Fixed an implementation bug where local
+  variable inference would incorrectly use the promoted type of a type variable.
+
+- **Breaking change** [#41362][]: Dart 2.0.0 made the clauses
+  `implements Function`, `extends Function`, or `with Function` have no effect
+  (spec section 19.6). We fixed an implementation bug that may be visible on
+  some rare scenarios.
+
+[#40675]: https://github.com/dart-lang/sdk/issues/40675
+[#41362]: https://github.com/dart-lang/sdk/issues/41362
+
+### Core libraries
+
+#### `dart:async`
+
+- **Breaking change** [#40676][]: Changed the return type of
+  `StreamSubscription.cancel()` to `Future<void>`. Previously, it was declared
+  to return `Future` and was allowed to return `null` at runtime.
+
+- **Breaking change** [#40681][]: The `runZoned()` function is split into two
+  functions: `runZoned()` and `runZonedGuarded()`, where the latter has a
+  required `onError` parameter, and the former has none. This prepares the
+  functions for null safety where the two functions will differ in the
+  nullability of their return types.
+
+- **Breaking change** [#40683][]: Errors passed to `Completer.completeError()`,
+  `Stream.addError()`, `Future.error()`, etc. can no longer be `null`. These
+  operations now _synchronously_ throw an exception if passed a `null` error.
+
+- Make stack traces non-null [#40130][]. Where methods like
+  `completer.completeError()` allow omitting a stack trace, the platform will
+  now insert a default stack trace rather than propagate a `null` value.
+
+  Error handling functions need no longer be prepared for `null` stack traces.
+
+[#40676]: https://github.com/dart-lang/sdk/issues/40676
+[#40681]: https://github.com/dart-lang/sdk/issues/40681
+[#40683]: https://github.com/dart-lang/sdk/issues/40683
+[#40130]: https://github.com/dart-lang/sdk/issues/40130
+
+#### `dart:core`
+
+- **Breaking change** [#40674][]: Three members on `RuneIterator` no longer
+  return `null` when accessed before the first call to `moveNext()`. Instead,
+  `current` and `rawIndex` return `-1` and `currentAsString` returns an empty
+  string.
+
+- **Breaking change** [#40678][]: The `String.fromEnvironment()` default value
+  for `defaultValue` is now an empty string instead of `null`. Likewise, the
+  default value for `int.fromEnvironment()`'s `defaultValue` parameter is zero.
+  Under null safety, a constructor cannot return `null`, so this prepares these
+  APIs for that.
+
+- The class `CastError` is deprecated, and all implementation specific classes
+  implementing `TypeError` or `CastError` now implement both. In a future
+  release, `CastError` will be removed. See issue [40763][] for details.
+
+- Adds `StackTrace.empty` constant which is the stack trace used as default
+  stack trace when no better alternative is available.
+
+- The class `TypeError` no longer extends `AssertionError`. This also means that
+  it no longer inherits the spurious `message` getter which was added to
+  `AssertionError` when the second operand to `assert` was allowed. The value of
+  that getter on a `TypeError` was the same string as returned by `toString()`,
+  so it is still available.
+
+- `ArgumentError.checkNotNull()` and the `RangeError` static methods
+  `checkValueInInterval()`, `checkValidIndex()` and `checkNotNegative()` all
+  return their first argument on success. This makes these functions more
+  convenient to use in-line in, for example, `=>` function bodies or constructor
+  initialization lists.
+
+[#40674]: https://github.com/dart-lang/sdk/issues/40674
+[#40678]: https://github.com/dart-lang/sdk/issues/40678
+[40763]: https://github.com/dart-lang/sdk/issues/40763
+
+#### `dart:developer`
+
+- The constructors for `TimelineTask` now accept an optional `filterKey`
+  parameter. If provided, the arguments for all events associated with the task
+  will contain an entry named `filterKey`, set to the value of the `filterKey`
+  parameter provided in the constructor. This will be used by tooling to allow
+  for better filtering of timeline events.
+
+#### `dart:ffi`
+
+- **Breaking change**: Changed `Pointer.asFunction()` and
+  `DynamicLibrary.lookupFunction()` to extension methods. Invoking them
+  dynamically previously already threw an exception, so the runtime behavior
+  stays the same. However, the extension methods are only visible if `dart:ffi`
+  is imported directly. This breaks code where `dart:ffi` is not directly
+  imported. To fix, add:
+
+  ```dart
+  import 'dart:ffi';
+  ```
+
+#### `dart:html`
+
+- **Breaking change** [#39627][]: Changed the return type of several HTML native
+  methods involving futures. In return types that matched `Future<List<T>>`,
+  `T was` changed to `dynamic`. These methods would have resulted in a runtime
+  error if they were used.
+
+- **Breaking change**: `Node.insertAllBefore()` erroneously had a return type of
+  `Node`, even though it was not returning anything. This has been corrected to
+  `void`.
+
+[#39627]: https://github.com/dart-lang/sdk/issues/39627
+
+#### `dart:io`
+
+- Class `HttpParser` will no longer throw an exception when a HTTP response
+  status code is within [0, 999]. Customized status codes in this range are now
+  valid.
+
+- **Breaking change** [#33501][]: The signature of `HttpHeaders` methods `add()`
+  and `set` have been changed to:
+
+  ```dart
+  void add(String name, Object value, {bool preserveHeaderCase: false})
+  void set(String name, Object value, {bool preserveHeaderCase: false})
+  ```
+
+  Setting `preserveHeaderCase` to `true` preserves the case of the `name`
+  parameter instead of converting it to lowercase. The `HttpHeader.forEach()`
+  method provides the current case of each header.
+
+  This is breaking only for classes extending or implementing `HttpHeaders` and
+  having their own `add` or `set` methods without the `bool preserveHeaderCase`
+  named parameter.
+
+- **Breaking change** [#40702][]: The `Socket` class now throws a
+  `SocketException` if the socket has been explicitly destroyed or upgraded to a
+  secure socket upon setting or getting socket options. Previously, setting a
+  socket option would be ignored and getting a socket option would return
+  `null`.
+
+- **Breaking change** [#40483][]: The `Process` class now throws a `StateError`
+  if the process is detached (`ProcessStartMode.detached` and
+  `ProcessStartMode.detachedWithStdio`) upon accessing the `exitCode` getter. It
+  now also throws when not connected to the child process's stdio
+  (`ProcessStartMode.detached` and `ProcessStartMode.inheritStdio`) upon
+  accessing the `stdin`, `stdout`, and `stderr` getters. Previously, these
+  getters would all return `null`.
+
+- **Breaking change** [#40706][]: The dummy object returned if `FileStat.stat()`
+  or `FileStat.statSync()` fail now contains Unix epoch timestamps instead of
+  `null` for the `accessed`, `changed`, and `modified` getters.
+
+- **Breaking change** [#40709][]: The `HeaderValue` class now parses more
+  strictly in two invalid edge cases. This is the class used to parse the
+  semicolon delimited parameters used in the `Accept`, `Authorization`,
+  `Content-Type`, and other such HTTP headers.
+
+  The empty parameter value without double quotes (which is not allowed by the
+  standards) is now parsed as the empty string rather than `null`. E.g.
+  `HeaderValue.parse("v;a=").parameters` now gives `{"a": ""}` rather than
+  `{"a": null}`.
+
+  Invalid inputs with unbalanced double quotes are now rejected. E.g.
+  `HeaderValue.parse('v;a="b').parameters` will now throw a `HttpException`
+  instead of giving `{"a": "b"}`.
+
+- The `HeaderValue.toString()` method now supports parameters with `null` values
+  by omitting the value. `HeaderValue("v", {"a": null, "b": "c"}).toString()`
+  now gives `v; a; b=c`. This behavior can be used to implement some features in
+  the `Accept` and `Sec-WebSocket-Extensions` headers.
+
+  Likewise the empty value and values using characters outside of [RFC 7230
+  tokens][] are now correctly implemented by double quoting such values with
+  escape sequences. For example:
+
+  ```dart
+  HeaderValue("v",
+      {"a": "A", "b": "(B)", "c": "", "d": "ø", "e": "\\\""}).toString()
+  ```
+
+  Gives: `v;a=A;b="(B)";c="";d="ø";e="\\\""`.
+
+- [Unix domain sockets][] are now supported on Linux, Android and MacOS, which
+  can be used by passing a `InternetAddress` of `InternetAddressType.Unix` into
+  the `connect()`, `startConnect()` and `bind()` methods. The `port` argument in
+  those methods will be ignored. The `port` getter always returns 0 for Unix
+  domain sockets.
+
+- Class `InternetAddressType` gains one more option `Unix`, which represents a
+  Unix domain address.
+
+- Class `InternetAddress`:
+
+  - `InternetAddress` constructor gains an optional `type` parameter. To create
+    a Unix domain address, `type` is set to `InternetAddressType.Unix` and
+    `address` is a file path.
+
+  - `InternetAddress` gains a new constructor `fromRawAddress()` that takes an
+    address in byte format for Internet addresses or raw file path for Unix
+    domain addresses.
+
+- **Breaking change** [#40681][]: The static methods `runZoned()` and
+  `runWithHttpOverrides()` on `HttpOverrides` no longer accept
+  `zoneSpecification` and `onError` parameters. Use the `runZoned()` or
+  `runZonedGuarded()` functions from `dart:async` directly if needing to specify
+  those.
+
+- Class `HttpClient` and `HttpServer`, when receiving `HttpRequest` or
+  `HttpClientResponse`, will now put a 8K size limit on its header fields and
+  values.
+
+[#33501]: https://github.com/dart-lang/sdk/issues/33501
+[#40702]: https://github.com/dart-lang/sdk/issues/40702
+[#40483]: https://github.com/dart-lang/sdk/issues/40483
+[#40706]: https://github.com/dart-lang/sdk/issues/40706
+[#40709]: https://github.com/dart-lang/sdk/issues/40709
+[rfc 7230 tokens]: https://tools.ietf.org/html/rfc7230#section-3.2.6
+[unix domain sockets]: https://en.wikipedia.org/wiki/Unix_domain_socket
+
+#### `dart:mirrors`
+
+- Added `MirrorSystem.neverType`.
+
+### Dart VM
+
+- Added `Dart_TypeDynamic`, `Dart_TypeVoid` and `Dart_TypeNever`. Type `dynamic`
+  can no longer by reached using `Dart_GetType(dart:core, dynamic)`.
+
+- Added the following methods to the VM embedding API:
+
+  - `Dart_GetNonNullableType()`
+  - `Dart_GetNullableType()`
+  - `Dart_TypeToNonNullable()`
+  - `Dart_TypeToNullable()`
+  - `Dart_IsLegacyType()`
+  - `Dart_IsNonNullableType()`
+  - `Dart_IsNullableType()`
+
+### Tools
+
+#### Dart Dev Compiler (DDC)
+
+We fixed several inconsistencies between DDC and Dart2JS so that users less
+frequently encounter code that is accepted by one compiler but then fails in the
+other.
+
+- **Breaking change**: Deleted the legacy (analyzer based) version of DDC. For
+  additional details see the [announcement][ddc].
+
+  - The `--kernel` option is now ignored and defaults to true. There is no
+    longer any way to invoke the legacy (analyzer based) version of DDC.
+
+  - Command line arguments that were only used for the legacy DDC have been
+    removed.
+
+  - The pre-compiled `dart_sdk.js` artifacts generated by legacy DDC have been
+    deleted from `dart-sdk/lib/dev_compiler` in favor of the versions located at
+    `dart-sdk/lib/dev_compiler/kernel`.
+
+- **Breaking change**: Functions passed to JavaScript using the recommended
+  `package:js` interop specification must now be wrapped with a call to
+  `allowInterop`. This behavior was always enforced by Dart2JS, but was not
+  enforced consistently by DDC. It is now enforced by both.
+
+- **Breaking change**: Constructors in `@JS()` classes must be marked with
+  `external`. Previously the `external` could be omitted in some cases with DDC
+  but doing so would cause incorrect behavior with Dart2JS.
+
+- JS interop classes with an index operator are now static errors.
+
+- All remaining support from the `dart:mirrors` library has been removed. Use of
+  this library on the web has been unsupported and prevented by the Dart build
+  systems since Dart v2.0.0. All known exception cases have been cleaned up.
+  This change makes DDC and Dart2JS now behave consistently.
+
+  The library can still be imported on web apps, but all APIs throw. In a future
+  breaking change release, imports to this library will likely become a
+  compile-time error.
+
+[ddc]: https://github.com/dart-lang/sdk/issues/38994
+
+#### Dart2JS
+
+A new representation of runtime types is enabled by default.
+
+This change is part of a long term goal of making runtime checks cheaper and
+more flexible for upcoming changes in the language. The new representation
+disentangles how types and classes are represented and makes types first-class
+to the compiler. This makes it possible to do certain kind of optimizations on
+type checks that were not possible before and will enable us to model
+non-nullable types in the near future.
+
+This change should not affect the semantics of your application, but it has some
+relatively small visible effects that we want to highlight:
+
+- Types are now canonicalized, this fixes a long standing bug that Types could
+  not be used in switch cases (issue [17207][]).
+
+- Code-size changes may be visible, but the difference is small overall. It is
+  more visible on smaller apps because the new implementation includes more
+  helper methods. On large apps we have even seen an overall code-size
+  reduction.
+
+- Certain checks are a lot faster. This is less noticeable if you are compiling
+  apps with `-O3` where checks are omitted altogether. Even with `-O3`, the
+  performance of some `is` checks used by your app may improve.
+
+- When using `-O3` and `-O4` incorrect type annotations could surface as errors.
+  The old type representation was accidentally lenient on some invalid type
+  annotations. We have only encountered this issue on programs that were not
+  tested properly at the js-interop program boundary.
+
+- `Type.toString()` has a small change that is rarely visible. For a long time,
+  Dart2JS has had support to erase unused type variables. Today, when Dart2JS is
+  given `--lax-runtime-type-to-string` (currently included in `-O2`, `-O3`, and
+  `-O4`) and it decides to erase the type variable of a class `Foo<T>`, then it
+  compiles expressions like `foo.runtimeType.toString()` to print `Foo`. With
+  the new representation, this will show `Foo<erased>` instead. This change may
+  be visible in error messages produced by type checks involving erased types.
+
+Because types and classes are represented separately, we will likely reevaluate
+restrictions of deferred libraries in the near future. For example, we could
+support referring to deferred types because types can be downloaded while
+classes are not.
+
+In the unlikely case you run into any issues, please file a bug so we can
+investigate. You can temporarily force the old type representation by passing
+`--use-old-rti` to Dart2JS if necessary, but our goal is to delete the old type
+representation soon.
+
+In addition, we fixed some inconsistencies between Dart2JS and DDC:
+
+- JS interop classes with an index operator are now static errors instead of
+  causing invalid code in Dart2JS.
+
+- **Breaking change**: The subtyping rule for generic functions is now more
+  forgiving. Corresponding type parameter bounds now only need to be mutual
+  subtypes rather than structurally equal up to renaming of bound type variables
+  and equating all top types.
+
+- **Breaking change**: Types are now normalized. See [normalization][] for the
+  full specification. Types will now be printed in their normal form, and mutual
+  subtypes with the same normal form will now be considered equal.
+
+- **Breaking change**: Constructors in `@JS()` classes must be marked with
+  `external`. Previously, the external could be omitted for unused constructors.
+  Omitting `external` for a constructor which is used would cause incorrect
+  behavior at runtime, now omitting it on any constructor is a static error.
+
+[17207]: https://github.com/dart-lang/sdk/issues/17207
+[normalization]:
+  https://github.com/dart-lang/language/blob/master/resources/type-system/normalization.md
+
+Other dart2js changes:
+
+- **Breaking change**: The `--package-root` flag, which was hidden and disabled
+  in Dart 2.0.0, has been completely removed. Passing this flag will now cause
+  `dart2js` to fail.
+
+#### Linter
+
+Updated the Linter to `0.1.114`, which includes:
+
+- Fixed `avoid_shadowing_type_parameters` to support extensions and mixins.
+- Updated `non_constant_identifier_names` to allow named constructors made up of
+  only underscores (`_`).
+- Updated `avoid_unused_constructor_parameters` to ignore unused params named in
+  all underscores (`_`).
+
+#### Analyzer
+
+- Removed support for the deprecated analysis options file name
+  `.analysis_options`.
+
+#### Pub
+
+- Added `pub outdated` command which lists outdated package dependencies, and
+  gives advice on how to upgrade.
+
+- `pub get` and `pub upgrade` now fetch version information about hosted
+  dependencies in parallel, improving the time package resolution performance.
+
+- `pub get` and `pub upgrade` no longer precompile executables from dependencies
+  by default. Instead they are precompiled on first `pub run`. Use
+  `pub get --precompile` to get the previous behavior.
+
+- Fixed missing retries of DNS failures during `pub get`.
+
+- If code contains imports for packages not listed in the package's
+  `pubspec.yaml` then `pub publish` will reject the package.
+
+- `pub publish` no longer requires the presence of a `homepage` field, if the
+  `repository` field is provided.
+
+- `pub publish` warns if non-pre-release packages depends on pre-release
+  packages or pre-release Dart SDKs.
+
+- Relative paths in `pubspec.lock` now use `/` also on Windows to make the file
+  sharable between machines.
+
+- Fixed language version in [`.dart_tool/package_config.json`][package config]
+  for packages without an explicit SDK constraint. Pub now writes an empty
+  language version where before the language version of the current SDK would be
+  used.
+
+- `%LOCALAPPDATA%` is now preferred over `%APPDATA%` when creating a pub cache
+  directory on Windows. `%LOCALAPPDATA%` is not copied when users roam between
+  devices.
+
+- `pub publish` warns if LICENSE and README.md files are not called those exact
+  names.
+
+- `pub repair cache` downloads hosted packages in parallel.
+
+[package config]:
+  https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/package-config-file-v2.md
+
+## 2.7.2 - 2020-03-23
+
+**Security advisory**: This is a patch release that addresses a vulnerability in
+`dart:html` [NodeValidator][] related to DOM clobbering of `previousSibling`.
+See the security advisory [CVE-2020-8923][cve-2020-8923] for more details.
+Thanks to **Vincenzo di Cicco** for finding and reporting this issue.
+
+This release also improves compatibility with ARMv8 processors (issue [40001][])
+and dart:io stability (issue [40589][]).
+
+[nodevalidator]: https://api.dart.dev/stable/dart-html/NodeValidator-class.html
+[cve-2020-8923]:
+  https://github.com/dart-lang/sdk/security/advisories/GHSA-hfq3-v9pv-p627
+[40001]: https://github.com/dart-lang/sdk/issues/40001
+[40589]: https://github.com/dart-lang/sdk/issues/40589
+
+## 2.7.1 - 2020-01-23
+
+This is a patch release that improves dart2js compile-time (issue [40217][]).
+
+[40217]: https://github.com/dart-lang/sdk/issues/40217
+
+**Breaking change**: The Dart SDK for macOS is now only available for x64 (issue
+[39810][]).
+
+[39810]: https://github.com/dart-lang/sdk/issues/39810
+
+## 2.7.0 - 2019-12-11
+
+**Extension methods** -- which we shipped in preview in 2.6.0 -- are no longer
+in preview, and are now officially supported as of 2.7.0. Learn more about them
+here:
+
+https://medium.com/dartlang/extension-methods-2d466cd8b308
+
+### Language
+
+- **Breaking change**: [Static extension members][] are accessible when imported
+  with a prefix (issue [671][]). In the extension method **preview** launch,
+  importing a library with a prefix hid all extension members in addition to
+  hiding the extension name, thereby making them inaccessible in the importing
+  library except via the explicit override syntax. Based on user feedback, we
+  have changed this to make extensions methods accessible even when imported
+  with a prefix.
+
+      ```dart
+        // "thing.dart"
+        class Thing {
+        }
+        extension Show on Thing {
+          void show() {
+            print("This is a thing");
+          }
+       }
+       // "client.dart"
+       import "thing.dart" as p;
+       void test() {
+         p.Thing().show(); // Previously an error, now resolves to Show.show
+       }
+      ```
+
+[static extension members]:
+  https://github.com/dart-lang/language/blob/master/accepted/2.6/static-extension-members/feature-specification.md
+[671]: https://github.com/dart-lang/language/issues/671
+
+### Core libraries
+
+#### `dart:io`
+
+- **Breaking change**: Added `IOOverrides.serverSocketBind` to aid in writing
+  tests that wish to mock `ServerSocket.bind`.
+
+#### `dart:typed_data`
+
+- Added new constructors, `.sublistView(TypedData, [start, end])` to all
+  `TypedData` classes. The constructor makes it easier, and less error-prone, to
+  create a view of (a slice of) another `TypedData` object.
+
+### Dart VM
+
+- New fields added to existing instances by a reload will now be initialized
+  lazily, as if the field was a late field. This makes the initialization order
+  program-defined, whereas previously it was undefined.
+
+### Tools
+
+#### Linter
+
+The Linter was updated to `0.1.104`, which includes:
+
+- updated `unnecessary_overrides` to allow overrides when annotations (besides
+  `@override` are specified)
+- updated `file_names` to allow names w/ leading `_`'s (and improved
+  performance)
+- new lint: `unnecessary_final`
+
+#### Pub
+
+- `pub get` generates
+  [`.dart_tool/package_config.json`](https://github.com/dart-lang/language/blob/62c036cc41b10fb543102d2f73ee132d1e2b2a0e/accepted/future-releases/language-versioning/package-config-file-v2.md)
+  in addition to `.packages` to support language versioning.
+
+- `pub publish` now warns about the old flutter plugin registration format.
+
+- `pub publish` now warns about the `author` field in pubspec.yaml being.
+  obsolete.
+
+- Show a proper error message when `git` is not installed.
+
+## 2.6.1 - 2019-11-11
+
+This is a patch release that reduces dart2js memory usage (issue [27883][]),
+improves stability on arm64 (issue [39090][]) and updates the Dart FFI
+documentation.
+
+[27883]: https://github.com/dart-lang/sdk/issues/27883
+[39090]: https://github.com/dart-lang/sdk/issues/39090
+
+## 2.6.0 - 2019-11-05
+
+### Language
+
+- **[IN PREVIEW]** [Static extension members][]: A new language feature allowing
+  specially declared static functions to be invoked like instance members on
+  expressions of appropriate static types is available in preview.
+
+  Static extension members are declared using a new `extension` declaration.
+  Example:
+
+  ```dart
+  extension MyFancyList<T> on List<T> {
+    /// Whether this list has an even length.
+    bool get isLengthEven => this.length.isEven;
+
+    /// Whether this list has an odd length.
+    bool get isLengthOdd => !isLengthEven;
+
+    /// List of values computed for each pairs of adjacent elements.
+    ///
+    /// The result always has one element less than this list,
+    /// if this list has any elements.
+    List<R> combinePairs<R>(R Function(T, T) combine) =>
+        [for (int i = 1; i < this.length; i++)
+            combine(this[i - 1], this[i])];
+  }
+  ```
+
+  Extension declarations cannot declare instance fields or constructors.
+  Extension members can be invoked explicitly,
+  `MyFancyList(intList).isLengthEven)`, or implicitly, `intList.isLengthEven`,
+  where the latter is recognized by `intList` matching the `List<T>` "on" type
+  of the declaration. An extension member cannot be called implicitly on an
+  expression whose static type has a member with the same base-name. In that
+  case, the interface member takes precedence. If multiple extension members
+  apply to the same implicit invocation, the most specific one is used, if there
+  is one such.
+
+  Extensions can be declared on any type, not just interface types.
+
+  ```dart
+  extension IntCounter on int {
+    /// The numbers from this number to, but not including, [end].
+    Iterable<int> to(int end) sync* {
+      int step = end < this ? -1 : 1;
+      for (int i = this; i != end; i += step) yield i;
+    }
+  }
+
+  extension CurryFunction<R, S, T> on R Function(S, T) {
+    /// Curry a binary function with its first argument.
+    R Function(T) curry(S first) => (T second) => this(first, second);
+  }
+  ```
+
+  [static extension members]:
+    https://github.com/dart-lang/language/blob/master/accepted/2.6/static-extension-members/feature-specification.md
+
+- **Breaking change** [#37985](https://github.com/dart-lang/sdk/issues/37985):
+  Inference is changed when using `Null` values in a `FutureOr` context. Namely,
+  constraints of the forms similar to `Null` <: `FutureOr<T>` now yield `Null`
+  as the solution for `T`. For example, the following code will now print
+  "Null", and it was printing "dynamic" before (note that the anonymous closure
+  `() {}` in the example has `Null` as its return type):
+
+  ```dart
+  import 'dart:async';
+
+  void foo<T>(FutureOr<T> Function() f) { print(T); }
+
+  main() { foo(() {}); }
+  ```
+
+### Core libraries
+
+- Default values of parameters of abstract methods are no longer available via
+  `dart:mirrors`.
+
+#### `dart:developer`
+
+- Added optional `parent` parameter to `TimelineTask` constructor to allow for
+  linking of asynchronous timeline events in the DevTools timeline view.
+
+#### `dart:ffi`
+
+- **Breaking change**: The API now makes use of static extension members. Static
+  extension members enable the `dart:ffi` API to be more precise with types, and
+  provide convenient access to memory through extension getters and setters. The
+  extension members on `Pointer` provide `.value` and `.value =` for accessing
+  the value in native memory and `[]` and `[]=` for indexed access. The method
+  `asExternalTypedData` has been replaced with `asTypedList` extension methods.
+  And finally, `Structs` do no longer have a type argument and are accessed
+  using the extension member `.ref` on `Pointer`. These changes makes the code
+  using `dart:ffi` much more concise.
+- **Breaking change**: The memory management has been removed
+  (`Pointer.allocate` and `Pointer.free`). Instead, memory management is
+  available in [package:ffi](https://pub.dev/packages/ffi).
+- **Breaking change**: `Pointer.offsetBy` was removed, use `cast` and
+  `elementAt` instead.
+- Faster memory load and stores.
+- The dartanalyzer (commandline and IDEs) now reports `dart:ffi` static errors.
+- Callbacks are now supported in AOT (ahead-of-time) compiled code.
+
+#### `dart:io`
+
+- Added `enableTimelineLogging` property to `HttpClient` which, when enabled,
+  will post HTTP connection and request information to the developer timeline
+  for all `HttpClient` instances.
+
+### Dart VM
+
+- Added a new tool for AOT compiling Dart programs to native, self-contained
+  executables. See https://dart.dev/tools/dart2native for additional details.
+
+### Dart for the Web
+
+#### Dart Dev Compiler (DDC)
+
+- Kernel DDC will no longer accept non-dill files as summary inputs.
+- Removed support for the deprecated web extension.
+
+### Tools
+
+#### Linter
+
+The Linter was updated to `0.1.101`, which includes:
+
+- fixed `diagnostic_describe_all_properties` to flag properties in
+  `Diagnosticable`s with no debug methods defined
+- fixed `noSuchMethod` exception in `camel_case_extensions` when analyzing
+  unnamed extensions
+- fixed `avoid_print` to catch tear-off usage
+- new lint: `avoid_web_libraries_in_flutter` (experimental)
+- (internal) prepare `unnecessary_lambdas` for coming `MethodInvocation` vs.
+  `FunctionExpressionInvocation` changes
+
+## 2.5.2 - 2019-10-08
+
+This is a patch release with properly signed binaries required for macOS
+Catalina (Issue [38765][]).
+
+[38765]: https://github.com/dart-lang/sdk/issues/38765
+
+## 2.5.1 - 2019-09-27
+
+This is a patch release that prevents type inference failures in the analyzer
+(Issue [38365][]).
+
+[38365]: https://github.com/dart-lang/sdk/issues/38365
+
+## 2.5.0 - 2019-09-10
+
+### Language
+
+The set of operations allowed in constant expressions has been expanded as
+described in the
+[constant update proposal](https://github.com/dart-lang/language/issues/61). The
+control flow and spread collection features shipped in Dart 2.3 are now also
+supported in constants as
+[described in the specification here](https://github.com/dart-lang/language/blob/master/accepted/2.3/unified-collections/feature-specification.md#constant-semantics).
+
+Specifically, it is now valid to use the following operations in constant
+expressions under the appropriate conditions:
+
+- Casts (`e as T`) and type tests (`e is T`).
+- Comparisons to `null`, even for types which override the `==` operator.
+- The `&`, `|`, and `^` binary operators on booleans.
+- The spread operators (`...` and `...?`).
+- An `if` element in a collection literal.
+
+```dart
+// Example: these are now valid constants.
+const Object i = 3;
+const list = [i as int];
+const set = {if (list is List<int>) ...list};
+const map = {if (i is int) i : "int"};
+```
+
+In addition, the semantics of constant evaluation has been changed as follows:
+
+- The `&&` operator only evaluates its second operand if the first evaluates to
+  true.
+- The `||` operator only evaluates its second operand if the first evaluates to
+  false.
+- The `??` operator only evaluates its second operand if the first evaluates to
+  null.
+- The conditional operator (`e ? e1 : e2`) only evaluates one of the two
+  branches, depending on the value of the first operand.
+
+```dart
+// Example: x is now a valid constant definition.
+const String s = null;
+const int x = (s == null) ? 0 : s.length;
+```
+
+### Core libraries
+
+- **Breaking change** [#36900](https://github.com/dart-lang/sdk/issues/36900):
+  The following methods and properties across various core libraries, which used
+  to declare a return type of `List<int>`, were updated to declare a return type
+  of `Uint8List`:
+
+  - `BytesBuilder.takeBytes()`
+  - `BytesBuilder.toBytes()`
+  - `Datagram.data`
+  - `File.readAsBytes()` (`Future<Uint8List>`)
+  - `File.readAsBytesSync()`
+  - `InternetAddress.rawAddress`
+  - `RandomAccessFile.read()` (`Future<Uint8List>`)
+  - `RandomAccessFile.readSync()`
+  - `RawSocket.read()`
+  - `Utf8Codec.encode()` (and `Utf8Encoder.convert()`)
+
+  In addition, the following classes were updated to implement
+  `Stream<Uint8List>` rather than `Stream<List<int>>`:
+
+  - `HttpRequest`
+  - `Socket`
+
+  **Possible errors and how to fix them**
+
+  - > The argument type 'Utf8Decoder' can't be assigned to the parameter type
+    > 'StreamTransformer<Uint8List, dynamic>'
+
+    > type 'Utf8Decoder' is not a subtype of type 'StreamTransformer' of
+    > 'streamTransformer'"
+
+    You can fix these call sites by updating your code to use
+    `StreamTransformer.bind()` instead of `Stream.transform()`, like so:
+
+    _Before:_ `stream.transform(utf8.decoder)` _After:_
+    `utf8.decoder.bind(stream)`
+
+  - > The argument type 'IOSink' can't be assigned to the parameter type
+    > 'StreamConsumer<Uint8List>'
+
+    > type '\_IOSinkImpl' is not a subtype of type 'StreamConsumer<Uint8List>'
+    > of 'streamConsumer'
+
+    You can fix these call sites by casting your stream instance to a
+    `Stream<List<int>>` before calling `.pipe()` on the stream, like so:
+
+    _Before:_ `stream.pipe(consumer)` _After:_
+    `stream.cast<List<int>>().pipe(consumer)`
+
+  Finally, the following typed lists were updated to have their `sublist()`
+  methods declare a return type that is the same as the source list:
+
+  - `Int8List.sublist()` → `Int8List`
+  - `Int16List.sublist()` → `Int16List`
+  - `Int32List.sublist()` → `Int32List`
+  - `Int64List.sublist()` → `Int64List`
+  - `Int32x4List.sublist()` → `Int32x4List`
+  - `Float32List.sublist()` → `Float32List`
+  - `Float64List.sublist()` → `Float64List`
+  - `Float32x4List.sublist()` → `Float32x4List`
+  - `Float64x2List.sublist()` → `Float64x2List`
+  - `Uint8List.sublist()` → `Uint8List`
+  - `Uint8ClampedList.sublist()` → `Uint8ClampedList`
+  - `Uint16List.sublist()` → `Uint16List`
+  - `Uint32List.sublist()` → `Uint32List`
+  - `Uint64List.sublist()` → `Uint64List`
+
+#### `dart:async`
+
+- Add `value` and `error` constructors on `Stream` to allow easily creating
+  single-value or single-error streams.
+
+#### `dart:core`
+
+- Update `Uri` class to support [RFC6874](https://tools.ietf.org/html/rfc6874):
+  "%25" or "%" can be appended to the end of a valid IPv6 representing a Zone
+  Identifier. A valid zone ID consists of unreversed character or Percent
+  encoded octet, which was defined in RFC3986. IPv6addrz = IPv6address "%25"
+  ZoneID
+
+  [29456]: https://github.com/dart-lang/sdk/issues/29456
+
+#### `dart:io`
+
+- **Breaking change** [#37192](https://github.com/dart-lang/sdk/issues/37192):
+  The `Cookie` class's constructor's `name` and `value` optional positional
+  parameters are now mandatory. The signature changes from:
+
+      Cookie([String name, String value])
+
+  to
+
+      Cookie(String name, String value)
+
+  However, it has not been possible to set `name` and `value` to null since Dart
+  1.3.0 (2014) where a bug made it impossible. Any code not using both
+  parameters or setting any to null would necessarily get a noSuchMethod
+  exception at runtime. This change catches such erroneous uses at compile time.
+  Since code could not previously correctly omit the parameters, this is not
+  really a breaking change.
+
+- **Breaking change** [#37192](https://github.com/dart-lang/sdk/issues/37192):
+  The `Cookie` class's `name` and `value` setters now validates that the strings
+  are made from the allowed character set and are not null. The constructor
+  already made these checks and this fixes the loophole where the setters didn't
+  also validate.
+
+### Dart VM
+
+### Tools
+
+#### Pub
+
+- Clean-up invalid git repositories in cache when fetching from git.
+- **Breaking change** [#36765](https://github.com/dart-lang/sdk/issues/36765):
+  Packages published to [pub.dev](https://pub.dev) can no longer contain git
+  dependencies. These packages will be rejected by the server.
+
+#### Linter
+
+The Linter was updated to `0.1.96`, which includes:
+
+- fixed false positives in `unnecessary_parens`
+- various changes to migrate to preferred analyzer APIs
+- rule test fixes
+
+#### Dartdoc
+
+Dartdoc was updated to `0.28.4`; this version includes several fixes and is
+based on a newer version of the analyzer package.
+
+## 2.4.1 - 2019-08-07
+
+This is a patch release that fixes a performance regression in JIT mode, as well
+as a potential crash of our AOT compiler.
+
+### Dart VM
+
+- Fixed a performance regression where usage of `Int32List` could trigger
+  repeated deoptimizations in JIT mode (Issue [37551][]).
+
+- Fixed a bug where usage of a static getter with name `length` could cause a
+  crash in our AOT compiler (Issue [35121][]).
+
+[37551]: https://github.com/dart-lang/sdk/issues/37551
+[35121]: https://github.com/dart-lang/sdk/issues/35121
+
+### Dart Dev Compiler (DDC)
+
+Callbacks passed to JS and wrapped with `allowInterop` or
+`allowInteropCaptureThis` are now strict about argument counts and argument
+types. This may mean that tests which were previously passing and relying on
+loose argument checking (too many or too few arguments, or arguments with too
+specific types like `List<Something>` instead of `List<dynamic>`) may start
+failing. This changes makes DDC behave more like dart2js with the default flags.
+
+## 2.4.0 - 2019-06-27
+
+### Core libraries
+
+#### `dart:isolate`
+
+- `TransferableTypedData` class was added to facilitate faster cross-isolate
+  communication of `Uint8List` data.
+
+- **Breaking change**: `Isolate.resolvePackageUri` will always throw an
+  `UnsupportedError` when compiled with dart2js or DDC. This was the only
+  remaining API in `dart:isolate` that didn't automatically throw since we
+  dropped support for this library in [Dart 2.0.0][1]. Note that the API already
+  throws in dart2js if the API is used directly without manually setting up a
+  `defaultPackagesBase` hook.
+
+[1]: https://github.com/dart-lang/sdk/blob/main/CHANGELOG.md#200---2018-08-07
+
+#### `dart:developer`
+
+- Exposed `result`, `errorCode` and `errorDetail` getters in
+  `ServiceExtensionResponse` to allow for better debugging of VM service
+  extension RPC results.
+
+#### `dart:io`
+
+- Fixed `Cookie` class interoperability with certain websites by allowing the
+  cookie values to be the empty string (Issue [35804][]) and not stripping
+  double quotes from the value (Issue [33327][]) in accordance with RFC 6265.
+
+  [33327]: https://github.com/dart-lang/sdk/issues/33327
+  [35804]: https://github.com/dart-lang/sdk/issues/35804
+
+- [#36971](https://github.com/dart-lang/sdk/issues/36971): The
+  `HttpClientResponse` interface has been extended with the addition of a new
+  `compressionState` getter, which specifies whether the body of a response was
+  compressed when it was received and whether it has been automatically
+  uncompressed via `HttpClient.autoUncompress`.
+
+  As part of this change, a corresponding new enum was added to `dart:io`:
+  `HttpClientResponseCompressionState`.
+
+  This is a **breaking change** for those implementing the `HttpClientResponse`
+  interface as subclasses will need to implement the new getter.
+
+#### `dart:async`
+
+- **Breaking change** [#36382](https://github.com/dart-lang/sdk/issues/36382):
+  The `await for` allowed `null` as a stream due to a bug in `StreamIterator`
+  class. This bug has now been fixed.
+
+#### `dart:core`
+
+- [#36171](https://github.com/dart-lang/sdk/issues/36171): The `RegExp`
+  interface has been extended with two new constructor named parameters:
+
+  - `unicode:` (`bool`, default: `false`), for Unicode patterns
+  - `dotAll:` (`bool`, default: `false`), to change the matching behavior of '.'
+    to also match line terminating characters.
+
+  Appropriate properties for these named parameters have also been added so
+  their use can be detected after construction.
+
+  In addition, `RegExp` methods that originally returned `Match` objects now
+  return a more specific subtype, `RegExpMatch`, which adds two features:
+
+  - `Iterable<String> groupNames`, a property that contains the names of all
+    named capture groups
+  - `String namedGroup(String name)`, a method that retrieves the match for the
+    given named capture group
+
+  This is a **breaking change** for implementers of the `RegExp` interface.
+  Subclasses will need to add the new properties and may have to update the
+  return types on overridden methods.
+
+### Language
+
+- **Breaking change** [#35097](https://github.com/dart-lang/sdk/issues/35097):
+  Covariance of type variables used in super-interfaces is now enforced. For
+  example, the following code was previously accepted and will now be rejected:
+
+```dart
+class A<X> {};
+class B<X> extends A<void Function(X)> {};
+```
+
+- The identifier `async` can now be used in asynchronous and generator
+  functions.
+
+### Dart for the Web
+
+#### Dart Dev Compiler (DDC)
+
+- Improve `NoSuchMethod` errors for failing dynamic calls. Now they include
+  specific information about the nature of the error such as:
+  - Attempting to call a null value.
+  - Calling an object instance with a null `call()` method.
+  - Passing too few or too many arguments.
+  - Passing incorrect named arguments.
+  - Passing too few or too many type arguments.
+  - Passing type arguments to a non-generic method.
+
+### Tools
+
+#### Linter
+
+The Linter was updated to `0.1.91`, which includes the following changes:
+
+- Fixed missed cases in `prefer_const_constructors`
+- Fixed `prefer_initializing_formals` to no longer suggest API breaking changes
+- Updated `omit_local_variable_types` to allow explicit `dynamic`s
+- Fixed null-reference in `unrelated_type_equality_checks`
+- New lint: `unsafe_html`
+- Broadened `prefer_null_aware_operators` to work beyond local variables.
+- Added `prefer_if_null_operators`.
+- Fixed `prefer_contains` false positives.
+- Fixed `unnecessary_parenthesis` false positives.
+- Fixed `prefer_asserts_in_initializer_lists` false positives
+- Fixed `curly_braces_in_flow_control_structures` to handle more cases
+- New lint: `prefer_double_quotes`
+- New lint: `sort_child_properties_last`
+- Fixed `type_annotate_public_apis` false positive for `static const`
+  initializers
+
+#### Pub
+
+- `pub publish` will no longer warn about missing dependencies for import
+  statements in `example/`.
+- OAuth2 authentication will explicitly ask for the `openid` scope.
+
+## 2.3.2 - 2019-06-11
+
+This is a patch version release with a security improvement.
+
+### Security vulnerability
+
+- **Security improvement:** On Linux and Android, starting a process with
+  `Process.run`, `Process.runSync`, or `Process.start` would first search the
+  current directory before searching `PATH` (Issue [37101][]). This behavior
+  effectively put the current working directory in the front of `PATH`, even if
+  it wasn't in the `PATH`. This release changes that behavior to only searching
+  the directories in the `PATH` environment variable. Operating systems other
+  than Linux and Android didn't have this behavior and aren't affected by this
+  vulnerability.
+
+  This vulnerability could result in execution of untrusted code if a command
+  without a slash in its name was run inside an untrusted directory containing
+  an executable file with that name:
+
+  ```dart
+  Process.run("ls", workingDirectory: "/untrusted/directory")
+  ```
+
+  This would attempt to run `/untrusted/directory/ls` if it existed, even though
+  it is not in the `PATH`. It was always safe to instead use an absolute path or
+  a path containing a slash.
+
+  This vulnerability was introduced in Dart 2.0.0.
+
+[37101]: https://github.com/dart-lang/sdk/issues/37101
+
+## 2.3.1 - 2019-05-21
+
+This is a patch version release with bug fixes.
+
+### Tools
+
+#### dart2js
+
+- Fixed a bug that caused the compiler to crash when it compiled UI-as-code
+  features within fields (Issue [36864][]).
+
+[36864]: https://github.com/dart-lang/sdk/issues/36864
+
+## 2.3.0 - 2019-05-08
+
+The focus in this release is on the new "UI-as-code" language features which
+make collections more expressive and declarative.
+
+### Language
+
+Flutter is growing rapidly, which means many Dart users are building UI in code
+out of big deeply-nested expressions. Our goal with 2.3.0 was to [make that kind
+of code easier to write and maintain][ui-as-code]. Collection literals are a
+large component, so we focused on three features to make collections more
+powerful. We'll use list literals in the examples below, but these features also
+work in map and set literals.
+
+[ui-as-code]:
+  https://medium.com/dartlang/making-dart-a-better-language-for-ui-f1ccaf9f546c
+
+#### Spread
+
+Placing `...` before an expression inside a collection literal unpacks the
+result of the expression and inserts its elements directly inside the new
+collection. Where before you had to write something like this:
+
+```dart
+CupertinoPageScaffold(
+  child: ListView(children: [
+    Tab2Header()
+  ]..addAll(buildTab2Conversation())
+    ..add(buildFooter())),
+);
+```
+
+Now you can write this:
+
+```dart
+CupertinoPageScaffold(
+  child: ListView(children: [
+    Tab2Header(),
+    ...buildTab2Conversation(),
+    buildFooter()
+  ]),
+);
+```
+
+If you know the expression might evaluate to null and you want to treat that as
+equivalent to zero elements, you can use the null-aware spread `...?`.
+
+#### Collection if
+
+Sometimes you might want to include one or more elements in a collection only
+under certain conditions. If you're lucky, you can use a `?:` operator to
+selectively swap out a single element, but if you want to exchange more than one
+or omit elements, you are forced to write imperative code like this:
+
+```dart
+Widget build(BuildContext context) {
+  var children = [
+    IconButton(icon: Icon(Icons.menu)),
+    Expanded(child: title)
+  ];
+
+  if (isAndroid) {
+    children.add(IconButton(icon: Icon(Icons.search)));
+  }
+
+  return Row(children: children);
+}
+```
+
+We now allow `if` inside collection literals to conditionally omit or (with
+`else`) swap out an element:
+
+```dart
+Widget build(BuildContext context) {
+  return Row(
+    children: [
+      IconButton(icon: Icon(Icons.menu)),
+      Expanded(child: title),
+      if (isAndroid)
+        IconButton(icon: Icon(Icons.search)),
+    ],
+  );
+}
+```
+
+Unlike the existing `?:` operator, a collection `if` can be composed with
+spreads to conditionally include or omit multiple items:
+
+```dart
+Widget build(BuildContext context) {
+  return Row(
+    children: [
+      IconButton(icon: Icon(Icons.menu)),
+      if (isAndroid) ...[
+        Expanded(child: title),
+        IconButton(icon: Icon(Icons.search)),
+      ]
+    ],
+  );
+}
+```
+
+#### Collection for
+
+In many cases, the higher-order methods on Iterable give you a declarative way
+to modify a collection in the context of a single expression. But some
+operations, especially involving both transforming and filtering, can be
+cumbersome to express in a functional style.
+
+To solve this problem, you can use `for` inside a collection literal. Each
+iteration of the loop produces an element which is then inserted in the
+resulting collection. Consider the following code:
+
+```dart
+var command = [
+  engineDartPath,
+  frontendServer,
+  ...fileSystemRoots.map((root) => "--filesystem-root=$root"),
+  ...entryPoints
+      .where((entryPoint) => fileExists("lib/$entryPoint.json"))
+      .map((entryPoint) => "lib/$entryPoint"),
+  mainPath
+];
+```
+
+With a collection `for`, the code becomes simpler:
+
+```dart
+var command = [
+  engineDartPath,
+  frontendServer,
+  for (var root in fileSystemRoots) "--filesystem-root=$root",
+  for (var entryPoint in entryPoints)
+    if (fileExists("lib/$entryPoint.json")) "lib/$entryPoint",
+  mainPath
+];
+```
+
+As you can see, all three of these features can be freely composed. For full
+details of the changes, see [the official proposal][ui-as-code proposal].
+
+[ui-as-code proposal]:
+  https://github.com/dart-lang/language/blob/master/accepted/future-releases/unified-collections/feature-specification.md
+
+**Note: These features are not currently supported in _const_ collection
+literals. In a future release, we intend to relax this restriction and allow
+spread and collection `if` inside const collections.**
+
+### Core library changes
+
+#### `dart:isolate`
+
+- Added `debugName` property to `Isolate`.
+- Added `debugName` optional parameter to `Isolate.spawn` and
+  `Isolate.spawnUri`.
+
+#### `dart:core`
+
+- RegExp patterns can now use lookbehind assertions.
+- RegExp patterns can now use named capture groups and named backreferences.
+  Currently, named group matches can only be retrieved in Dart either by the
+  implicit index of the named group or by downcasting the returned Match object
+  to the type RegExpMatch. The RegExpMatch interface contains methods for
+  retrieving the available group names and retrieving a match by group name.
+
+### Dart VM
+
+- The VM service now requires an authentication code by default. This behavior
+  can be disabled by providing the `--disable-service-auth-codes` flag.
+
+- Support for deprecated flags '-c' and '--checked' has been removed.
+
+### Dart for the Web
+
+#### dart2js
+
+A binary format was added to dump-info. The old JSON format is still available
+and provided by default, but we are starting to deprecate it. The new binary
+format is more compact and cheaper to generate. On some large apps we tested, it
+was 4x faster to serialize and used 6x less memory.
+
+To use the binary format today, use `--dump-info=binary`, instead of
+`--dump-info`.
+
+What to expect next?
+
+- The [visualizer tool][visualizer] will not be updated to support the new
+  binary format, but you can find several command-line tools at
+  `package:dart2js_info` that provide similar features to those in the
+  visualizer.
+
+- The command-line tools in `package:dart2js_info` also work with the old JSON
+  format, so you can start using them even before you enable the new format.
+
+- In a future release `--dump-info` will default to `--dump-info=binary`. At
+  that point, there will be an option to fallback to the JSON format, but the
+  visualizer tool will be deprecated.
+
+- A release after that, the JSON format will no longer be available from
+  dart2js, but may be available from a command-line tool in
+  `package:dart2js_info`.
+
+[visualizer]: https://dart-lang.github.io/dump-info-visualizer/
+
+### Tools
+
+#### dartfmt
+
+- Tweak set literal formatting to follow other collection literals.
+- Add support for "UI as code" features.
+- Properly format trailing commas in assertions.
+- Improve indentation of adjacent strings in argument lists.
+
+#### Linter
+
+The Linter was updated to `0.1.86`, which includes the following changes:
+
+- Added the following lints: `prefer_inlined_adds`,
+  `prefer_for_elements_to_map_fromIterable`,
+  `prefer_if_elements_to_conditional_expressions`,
+  `diagnostic_describe_all_properties`.
+- Updated `file_names` to skip prefixed-extension Dart files (`.css.dart`,
+  `.g.dart`, etc.).
+- Fixed false positives in `unnecessary_parenthesis`.
+
+#### Pub
+
+- Added a CHANGELOG validator that complains if you `pub publish` without
+  mentioning the current version.
+- Removed validation of library names when doing `pub publish`.
+- Added support for `pub global activate`ing package from a custom pub URL.
+- Added subcommand: `pub logout`. Logs you out of the current session.
+
+#### Dart native
+
+Initial support for compiling Dart apps to native machine code has been added.
+Two new tools have been added to the `bin` folder of the Dart SDK:
+
+- `dart2aot`: AOT (ahead-of-time) compiles a Dart program to native machine
+  code. The tool is supported on Windows, macOS, and Linux.
+
+- `dartaotruntime`: A small runtime used for executing an AOT compiled program.
+
+## 2.2.0 - 2019-02-26
+
+### Language
+
+Sets now have a literal syntax like lists and maps do:
+
+```dart
+var set = {1, 2, 3};
+```
+
+Using curly braces makes empty sets ambiguous with maps:
+
+```dart
+var collection = {}; // Empty set or map?
+```
+
+To avoid breaking existing code, an ambiguous literal is treated as a map. To
+create an empty set, you can rely on either a surrounding context type or an
+explicit type argument:
+
+```dart
+// Variable type forces this to be a set:
+Set<int> set = {};
+
+// A single type argument means this must be a set:
+var set2 = <int>{};
+```
+
+Set literals are released on all platforms. The `set-literals` experiment flag
+has been disabled.
+
+### Tools
+
+#### Analyzer
+
+- The `DEPRECATED_MEMBER_USE` hint was split into two hints:
+
+  - `DEPRECATED_MEMBER_USE` reports on usage of `@deprecated` members declared
+    in a different package.
+  - `DEPRECATED_MEMBER_USE_FROM_SAME_PACKAGE` reports on usage of `@deprecated`
+    members declared in the same package.
+
+#### Linter
+
+Upgraded the linter to `0.1.82` which adds the following improvements:
+
+- Added `provide_deprecation_message`, and
+  `use_full_hex_values_for_flutter_colors`, `prefer_null_aware_operators`.
+- Fixed `prefer_const_declarations` set literal false-positives.
+- Updated `prefer_collection_literals` to support set literals.
+- Updated `unnecessary_parenthesis` play nicer with cascades.
+- Removed deprecated lints from the "all options" sample.
+- Stopped registering "default lints".
+- Fixed `hash_and_equals` to respect `hashCode` fields.
+
+### Other libraries
+
+#### `package:kernel`
+
+- **Breaking change:** The `klass` getter on the `InstanceConstant` class in the
+  Kernel AST API has been renamed to `classNode` for consistency.
+
+- **Breaking change:** Updated `Link` implementation to utilize true symbolic
+  links instead of junctions on Windows. Existing junctions will continue to
+  work with the new `Link` implementation, but all new links will create
+  symbolic links.
+
+  To create a symbolic link, Dart must be run with administrative privileges or
+  Developer Mode must be enabled, otherwise a `FileSystemException` will be
+  raised with errno set to `ERROR_PRIVILEGE_NOT_HELD` (Issue [33966]).
+
+[33966]: https://github.com/dart-lang/sdk/issues/33966
+
+## 2.1.1 - 2019-02-18
+
+This is a patch version release. Again, the team's focus was mostly on improving
+performance and stability after the large changes in Dart 2.0.0. In particular,
+dart2js now always uses the "fast startup" emitter and the old emitter has been
+removed.
+
+There are a couple of very minor **breaking changes:**
+
+- In `dart:io`, adding to a closed `IOSink` now throws a `StateError`.
+
+- On the Dart VM, a soundness hole when using `dart:mirrors` to reflectively
+  invoke a method in an incorrect way that violates its static types has been
+  fixed (Issue [35611][]).
+
+### Language
+
+This release has no language changes.
+
+### Core library
+
+#### `dart:core`
+
+- Made `DateTime.parse()` also recognize `,` as a valid decimal separator when
+  parsing from a string (Issue [35576][]).
+
+[35576]: https://github.com/dart-lang/sdk/issues/35576
+
+#### `dart:html`
+
+- Added methods `Element.removeAttribute`, `Element.removeAttributeNS`,
+  `Element.hasAttribute` and `Element.hasAttributeNS`. (Issue [35655][]).
+- Improved dart2js compilation of `element.attributes.remove(name)` to generate
+  `element.removeAttribute(name)`, so that there is no performance reason to
+  migrate to the above methods.
+- Fixed a number of `dart:html` bugs:
+
+  - Fixed HTML API's with callback typedef to correctly convert Dart functions
+    to JS functions (Issue [35484]).
+  - HttpStatus constants exposed in `dart:html` (Issue [34318]).
+  - Expose DomName `ondblclick` and `dblclickEvent` for Angular analyzer.
+  - Fixed `removeAll` on `classes`; `elements` parameter should be
+    `Iterable<Object>` to match Set's `removeAll` not `Iterable<E>` (Issue
+    [30278]).
+  - Fixed a number of methods on DataTransferItem, Entry, FileEntry and
+    DirectoryEntry which previously returned NativeJavaScriptObject. This fixes
+    handling drag/drop of files/directories (Issue [35510]).
+  - Added ability to allow local file access from Chrome browser in ddb.
+
+[35655]: https://github.com/dart-lang/sdk/issues/35655
+[30278]: https://github.com/dart-lang/sdk/issues/30278
+[34318]: https://github.com/dart-lang/sdk/issues/34318
+[35484]: https://github.com/dart-lang/sdk/issues/35484
+[35510]: https://github.com/dart-lang/sdk/issues/35510
+
+#### `dart:io`
+
+- **Breaking change:** Adding to a closed `IOSink` now throws a `StateError`.
+- Added ability to get and set low level socket options.
+
+[29554]: https://github.com/dart-lang/sdk/issues/29554
+
+### Dart VM
+
+In previous releases it was possible to violate static types using
+`dart:mirrors`. This code would run without any TypeErrors and print
+"impossible" output:
+
+```dart
+import 'dart:mirrors';
+
+class A {
+  void method(int v) {
+    if (v != null && v is! int) {
+      print("This should be impossible: expected null or int got ${v}");
+    }
+  }
+}
+
+void main() {
+  final obj = A();
+  reflect(obj).invoke(#method, ['not-an-number']);
+}
+```
+
+This bug is fixed now. Only code that already violates static typing will break.
+See Issue [35611][] for more details.
+
+[35611]: https://github.com/dart-lang/sdk/issues/35611
+
+### Dart for the Web
+
+#### dart2js
+
+- The old "full emitter" back-end is removed and dart2js always uses the "fast
+  startup" back-end. The generated fast startup code is optimized to load
+  faster, even though it can be slightly larger. The `--fast-startup` and
+  `--no-fast-startup` are allowed but ignored. They will be removed in a future
+  version.
+
+- We fixed a bug in how deferred constructor calls were incorrectly not marked
+  as deferred. The old behavior didn't cause breakages, but was imprecise and
+  pushed more code to the main output unit.
+
+- A new deferred split algorithm implementation was added.
+
+  This implementation fixes a soundness bug and addresses performance issues of
+  the previous implementation, because of that it can have a visible impact on
+  apps. In particular:
+
+  - We fixed a performance issue which was introduced when we migrated to the
+    common front-end. On large apps, the fix can cut 2/3 of the time spent on
+    this task.
+
+  - We fixed a bug in how inferred types were categorized (Issue [35311][]). The
+    old behavior was unsound and could produce broken programs. The fix may
+    cause more code to be pulled into the main output unit.
+
+    This shows up frequently when returning deferred values from closures since
+    the closure's inferred return type is the deferred type. For example, if you
+    have:
+
+    ```dart
+    () async {
+      await deferred_prefix.loadLibrary();
+      return new deferred_prefix.Foo();
+    }
+    ```
+
+    The closure's return type is `Future<Foo>`. The old implementation defers
+    `Foo`, and incorrectly makes the return type `Future<dynamic>`. This may
+    break in places where the correct type is expected.
+
+    The new implementation will not defer `Foo`, and will place it in the main
+    output unit. If your intent is to defer it, then you need to ensure the
+    return type is not inferred to be `Foo`. For example, you can do so by
+    changing the code to a named closure with a declared type, or by ensuring
+    that the return expression has the type you want, like:
+
+    ```dart
+    () async {
+      await deferred_prefix.loadLibrary();
+      return new deferred_prefix.Foo() as dynamic;
+    }
+    ```
+
+    Because the new implementation might require you to inspect and fix your
+    app, we exposed two temporary flags:
+
+  - The `--report-invalid-deferred-types` causes dart2js to run both the old and
+    new algorithms and report any cases where an invalid type was detected.
+
+  - The `--new-deferred-split` flag enables this new algorithm.
+
+- The `--categories=*` flag is being replaced. `--categories=all` was only used
+  for testing and it is no longer supported. `--categories=Server` continues to
+  work at this time but it is deprecated, please use `--server-mode` instead.
+
+- The `--library-root` flag was replaced by `--libraries-spec`. This flag is
+  rarely used by developers invoking dart2js directly. It's important for
+  integrating dart2js with build systems. See `--help` for more details on the
+  new flag.
+
+[35311]: https://github.com/dart-lang/sdk/issues/35311
+
+### Tools
+
+#### Analyzer
+
+- Support for `declarations-casts` has been removed and the `implicit-casts`
+  option now has the combined semantics of both options. This means that users
+  that disable `implicit-casts` might now see errors that were not previously
+  being reported.
+
+- New hints added:
+
+  - `NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR` and
+    `NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR_USING_NEW` inform you when a
+    `@literal` const constructor is called in a non-const context (or with
+    `new`).
+  - `INVALID_LITERAL_ANNOTATION` reports when something other than a const
+    constructor is annotated with `@literal`.
+  - `SUBTYPE_OF_SEALED_CLASS` reports when any class or mixin subclasses
+    (extends, implements, mixes in, or constrains to) a `@sealed` class, and the
+    two are declared in different packages.
+  - `MIXIN_ON_SEALED_CLASS` reports when a `@sealed` class is used as a
+    superclass constraint of a mixin.
+
+#### dartdoc
+
+Default styles now work much better on mobile. Simple browsing and searching of
+API docs now work in many cases.
+
+Upgraded the linter to `0.1.78` which adds the following improvements:
+
+- Added `prefer_final_in_for_each`, `unnecessary_await_in_return`,
+  `use_function_type_syntax_for_parameters`, `avoid_returning_null_for_future`,
+  and `avoid_shadowing_type_parameters`.
+- Updated `invariant_booleans` status to experimental.
+- Fixed `type_annotate_public_apis` false positives on local functions.
+- Fixed `avoid_shadowing_type_parameters` to report shadowed type parameters in
+  generic typedefs.
+- Fixed `use_setters_to_change_properties` to not wrongly lint overriding
+  methods.
+- Fixed `cascade_invocations` to not lint awaited targets.
+- Fixed `prefer_conditional_assignment` false positives.
+- Fixed `join_return_with_assignment` false positives.
+- Fixed `cascade_invocations` false positives.
+- Deprecated `prefer_bool_in_asserts` as it is redundant in Dart 2.
+
+## 2.1.0 - 2018-11-15
+
+This is a minor version release. The team's focus was mostly on improving
+performance and stability after the large changes in Dart 2.0.0. Notable
+changes:
+
+- We've introduced a dedicated syntax for declaring a mixin. Instead of the
+  `class` keyword, it uses `mixin`:
+
+  ```dart
+  mixin SetMixin<E> implements Set<E> {
+    ...
+  }
+  ```
+
+  The new syntax also enables `super` calls inside mixins.
+
+- Integer literals now work in double contexts. When passing a literal number to
+  a function that expects a `double`, you no longer need an explicit `.0` at the
+  end of the number. In releases before 2.1, you need code like this when
+  setting a double like `fontSize`:
+
+  ```dart
+  TextStyle(fontSize: 18.0)
+  ```
+
+  Now you can remove the `.0`:
+
+  ```dart
+  TextStyle(fontSize: 18)
+  ```
+
+  In releases before 2.1, `fontSize : 18` causes a static error. This was a
+  common mistake and source of friction.
+
+- **Breaking change:** A number of static errors that should have been detected
+  and reported were not supported in 2.0.0. These are reported now, which means
+  existing incorrect code may show new errors.
+
+- `dart:core` now exports `Future` and `Stream`. You no longer need to import
+  `dart:async` to use those very common types.
+
+### Language
+
+- Introduced a new syntax for mixin declarations.
+
+  ```dart
+  mixin SetMixin<E> implements Set<E> {
+    ...
+  }
+  ```
+
+  Most classes that are intended to be used as mixins are intended to _only_ be
+  used as mixins. The library author doesn't want users to be able to construct
+  or subclass the class. The new syntax makes that intent clear and enforces it
+  in the type system. It is an error to extend or construct a type declared
+  using `mixin`. (You can implement it since mixins expose an implicit
+  interface.)
+
+  Over time, we expect most mixin declarations to use the new syntax. However,
+  if you have a "mixin" class where users _are_ extending or constructing it,
+  note that moving it to the new syntax is a breaking API change since it
+  prevents users from doing that. If you have a type like this that is a mixin
+  as well as being a concrete class and/or superclass, then the existing syntax
+  is what you want.
+
+  If you need to use a `super` inside a mixin, the new syntax is required. This
+  was previously only allowed with the experimental `--supermixins` flag because
+  it has some complex interactions with the type system. The new syntax
+  addresses those issues and lets you use `super` calls by declaring the
+  superclass constraint your mixin requires:
+
+  ```dart
+  class Superclass {
+    superclassMethod() {
+      print("in superclass");
+    }
+  }
+
+  mixin SomeMixin on Superclass {
+    mixinMethod() {
+      // This is OK:
+      super.superclassMethod();
+    }
+  }
+
+  class GoodSub extends Superclass with SomeMixin {}
+
+  class BadSub extends Object with SomeMixin {}
+  // Error: Since the super() call in mixinMethod() can't find a
+  // superclassMethod() to call, this is prohibited.
+  ```
+
+  Even if you don't need to use `super` calls, the new mixin syntax is good
+  because it clearly expresses that you intend the type to be mixed in.
+
+- Allow integer literals to be used in double contexts. An integer literal used
+  in a place where a double is required is now interpreted as a double value.
+  The numerical value of the literal needs to be precisely representable as a
+  double value.
+
+- Integer literals compiled to JavaScript are now allowed to have any value that
+  can be exactly represented as a JavaScript `Number`. They were previously
+  limited to such numbers that were also representable as signed 64-bit
+  integers.
+
+**(Breaking)** A number of static errors that should have been detected and
+reported were not supported in 2.0.0. These are reported now, which means
+existing incorrect code may show new errors:
+
+- **Setters with the same name as the enclosing class aren't allowed.** (Issue
+  [34225][].) It is not allowed to have a class member with the same name as the
+  enclosing class:
+
+  ```dart
+  class A {
+    set A(int x) {}
+  }
+  ```
+
+  Dart 2.0.0 incorrectly allows this for setters (only). Dart 2.1.0 rejects it.
+
+  _To fix:_ This is unlikely to break anything, since it violates all style
+  guides anyway.
+
+- **Constant constructors cannot redirect to non-constant constructors.** (Issue
+  [34161][].) It is not allowed to have a constant constructor that redirects to
+  a non-constant constructor:
+
+  ```dart
+  class A {
+    const A.foo() : this(); // Redirecting to A()
+    A() {}
+  }
+  ```
+
+  Dart 2.0.0 incorrectly allows this. Dart 2.1.0 rejects it.
+
+  _To fix:_ Make the target of the redirection a properly const constructor.
+
+- **Abstract methods may not unsoundly override a concrete method.** (Issue
+  [32014][].) Concrete methods must be valid implementations of their
+  interfaces:
+
+  ```dart
+  class A {
+    num get thing => 2.0;
+  }
+
+  abstract class B implements A {
+    int get thing;
+  }
+
+  class C extends A with B {}
+  // 'thing' from 'A' is not a valid override of 'thing' from 'B'.
+
+  main() {
+    print(new C().thing.isEven); // Expects an int but gets a double.
+  }
+  ```
+
+  Dart 2.0.0 allows unsound overrides like the above in some cases. Dart 2.1.0
+  rejects them.
+
+  _To fix:_ Relax the type of the invalid override, or tighten the type of the
+  overridden method.
+
+- **Classes can't implement FutureOr.** (Issue [33744][].) Dart doesn't allow
+  classes to implement the FutureOr type:
+
+  ```dart
+  class A implements FutureOr<Object> {}
+  ```
+
+  Dart 2.0.0 allows classes to implement FutureOr. Dart 2.1.0 does not.
+
+  _To fix:_ Don't do this.
+
+- **Type arguments to generic typedefs must satisfy their bounds.** (Issue
+  [33308][].) If a parameterized typedef specifies a bound, actual arguments
+  must be checked against it:
+
+  ```dart
+  class A<X extends int> {}
+
+  typedef F<Y extends int> = A<Y> Function();
+
+  F<num> f = null;
+  ```
+
+  Dart 2.0.0 allows bounds violations like `F<num>` above. Dart 2.1.0 rejects
+  them.
+
+  _To fix:_ Either remove the bound on the typedef parameter, or pass a valid
+  argument to the typedef.
+
+- **Constructor invocations must use valid syntax, even with optional `new`.**
+  (Issue [34403][].) Type arguments to generic named constructors go after the
+  class name, not the constructor name, even when used without an explicit
+  `new`:
+
+  ```dart
+  class A<T> {
+    A.foo() {}
+  }
+
+  main() {
+    A.foo<String>(); // Incorrect syntax, was accepted in 2.0.0.
+    A<String>.foo(); // Correct syntax.
+  }
+  ```
+
+  Dart 2.0.0 accepts the incorrect syntax when the `new` keyword is left out.
+  Dart 2.1.0 correctly rejects this code.
+
+  _To fix:_ Move the type argument to the correct position after the class name.
+
+- **Instance members should shadow prefixes.** (Issue [34498][].) If the same
+  name is used as an import prefix and as a class member name, then the class
+  member name takes precedence in the class scope.
+
+  ```dart
+  import 'dart:core';
+  import 'dart:core' as core;
+
+  class A {
+    core.List get core => null; // "core" refers to field, not prefix.
+  }
+  ```
+
+  Dart 2.0.0 incorrectly resolves the use of `core` in `core.List` to the prefix
+  name. Dart 2.1.0 correctly resolves this to the field name.
+
+  _To fix:_ Change the prefix name to something which does not clash with the
+  instance member.
+
+- **Implicit type arguments in extends clauses must satisfy the class bounds.**
+  (Issue [34532][].) Implicit type arguments for generic classes are computed if
+  not passed explicitly, but when used in an `extends` clause they must be
+  checked for validity:
+
+  ```dart
+  class Foo<T> {}
+
+  class Bar<T extends Foo<T>> {}
+
+  class Baz extends Bar {} // Should error because Bar completes to Bar<Foo>
+  ```
+
+  Dart 2.0.0 accepts the broken code above. Dart 2.1.0 rejects it.
+
+  _To fix:_ Provide explicit type arguments to the superclass that satisfy the
+  bound for the superclass.
+
+- **Mixins must correctly override their superclasses.** (Issue [34235][].) In
+  some rare cases, combinations of uses of mixins could result in invalid
+  overrides not being caught:
+
+  ```dart
+  class A {
+    num get thing => 2.0;
+  }
+
+  class M1 {
+    int get thing => 2;
+  }
+
+  class B = A with M1;
+
+  class M2 {
+    num get thing => 2.0;
+  }
+
+  class C extends B with M2 {} // 'thing' from 'M2' not a valid override.
+
+  main() {
+    M1 a = new C();
+    print(a.thing.isEven); // Expects an int but gets a double.
+  }
+  ```
+
+  Dart 2.0.0 accepts the above example. Dart 2.1.0 rejects it.
+
+  _To fix:_ Ensure that overriding methods are correct overrides of their
+  superclasses, either by relaxing the superclass type, or tightening the
+  subclass/mixin type.
+
+[32014]: https://github.com/dart-lang/sdk/issues/32014
+[33308]: https://github.com/dart-lang/sdk/issues/33308
+[33744]: https://github.com/dart-lang/sdk/issues/33744
+[34161]: https://github.com/dart-lang/sdk/issues/34161
+[34225]: https://github.com/dart-lang/sdk/issues/34225
+[34235]: https://github.com/dart-lang/sdk/issues/34235
+[34403]: https://github.com/dart-lang/sdk/issues/34403
+[34498]: https://github.com/dart-lang/sdk/issues/34498
+[34532]: https://github.com/dart-lang/sdk/issues/34532
+
+### Core libraries
+
+#### `dart:async`
+
+- Fixed a bug where calling `stream.take(0).drain(value)` would not correctly
+  forward the `value` through the returned `Future`.
+- Added a `StreamTransformer.fromBind` constructor.
+- Updated `Stream.fromIterable` to send a done event after the error when the
+  iterator's `moveNext` throws, and handle if the `current` getter throws (issue
+  [33431][]).
+
+[33431]: http://dartbug.com/33431
+
+#### `dart:core`
+
+- Added `HashMap.fromEntries` and `LinkedHashmap.fromEntries` constructors.
+- Added `ArgumentError.checkNotNull` utility method.
+- Made `Uri` parsing more permissive about `[` and `]` occurring in the path,
+  query or fragment, and `#` occurring in fragment.
+- Exported `Future` and `Stream` from `dart:core`.
+- Added operators `&`, `|` and `^` to `bool`.
+- Added missing methods to `UnmodifiableMapMixin`. Some maps intended to be
+  unmodifiable incorrectly allowed new methods added in Dart 2 to succeed.
+- Deprecated the `provisional` annotation and the `Provisional` annotation
+  class. These should have been removed before releasing Dart 2.0, and they have
+  no effect.
+
+#### `dart:html`
+
+Fixed Service Workers and any Promise/Future API with a Dictionary parameter.
+
+APIs in dart:html (that take a Dictionary) will receive a Dart Map parameter.
+The Map parameter must be converted to a Dictionary before passing to the
+browser's API. Before this change, any Promise/Future API with a Map/Dictionary
+parameter never called the Promise and didn't return a Dart Future - now it
+does.
+
+This caused a number of breaks especially in Service Workers (register, etc.).
+Here is a complete list of the fixed APIs:
+
+- BackgroundFetchManager
+  - `Future<BackgroundFetchRegistration> fetch(String id, Object requests, [Map options])`
+- CacheStorage
+  - `Future match(/*RequestInfo*/ request, [Map options])`
+- CanMakePayment
+  - `Future<List<Client>> matchAll([Map options])`
+- CookieStore
+  - `Future getAll([Map options])`
+  - `Future set(String name, String value, [Map options])`
+- CredentialsContainer
+  - `Future get([Map options])`
+  - `Future create([Map options])`
+- ImageCapture
+  - `Future setOptions(Map photoSettings)`
+- MediaCapabilities
+  - `Future<MediaCapabilitiesInfo> decodingInfo(Map configuration)`
+  - `Future<MediaCapabilitiesInfo> encodingInfo(Map configuration)`
+- MediaStreamTrack
+  - `Future applyConstraints([Map constraints])`
+- Navigator
+  - `Future requestKeyboardLock([List<String> keyCodes])`
+  - `Future requestMidiAccess([Map options])`
+  - `Future share([Map data])`
+- OffscreenCanvas
+  - `Future<Blob> convertToBlob([Map options])`
+- PaymentInstruments
+  - `Future set(String instrumentKey, Map details)`
+- Permissions
+  - `Future<PermissionStatus> query(Map permission)`
+  - `Future<PermissionStatus> request(Map permissions)`
+  - `Future<PermissionStatus> revoke(Map permission)`
+- PushManager
+  - `Future permissionState([Map options])`
+  - `Future<PushSubscription> subscribe([Map options])`
+- RtcPeerConnection
+
+  - Changed:
+
+    ```dart
+    Future createAnswer([options_OR_successCallback,
+        RtcPeerConnectionErrorCallback failureCallback,
+        Map mediaConstraints])
+    ```
+
+    to:
+
+    ```dart
+    Future<RtcSessionDescription> createAnswer([Map options])
+    ```
+
+  - Changed:
+
+    ```dart
+    Future createOffer([options_OR_successCallback,
+        RtcPeerConnectionErrorCallback failureCallback,
+        Map rtcOfferOptions])
+    ```
+
+    to:
+
+    ```dart
+    Future<RtcSessionDescription> createOffer([Map options])
+    ```
+
+  - Changed:
+
+    ```dart
+    Future setLocalDescription(Map description,
+        VoidCallback successCallback,
+        [RtcPeerConnectionErrorCallback failureCallback])
+    ```
+
+    to:
+
+    ```dart
+    Future setLocalDescription(Map description)
+    ```
+
+  - Changed:
+
+    ```dart
+    Future setLocalDescription(Map description,
+        VoidCallback successCallback,
+        [RtcPeerConnectionErrorCallback failureCallback])
+    ```
+
+    to:
+
+    ```dart
+    Future setRemoteDescription(Map description)
+    ```
+
+- ServiceWorkerContainer
+  - `Future<ServiceWorkerRegistration> register(String url, [Map options])`
+- ServiceWorkerRegistration
+  - `Future<List<Notification>> getNotifications([Map filter])`
+  - `Future showNotification(String title, [Map options])`
+- VRDevice
+  - `Future requestSession([Map options])`
+  - `Future supportsSession([Map options])`
+- VRSession
+  - `Future requestFrameOfReference(String type, [Map options])`
+- Window
+  - `Future fetch(/*RequestInfo*/ input, [Map init])`
+- WorkerGlobalScope
+  - `Future fetch(/*RequestInfo*/ input, [Map init])`
+
+In addition, exposed Service Worker "self" as a static getter named "instance".
+The instance is exposed on four different Service Worker classes and can throw a
+InstanceTypeError if the instance isn't of the class expected
+(WorkerGlobalScope.instance will always work and not throw):
+
+- `SharedWorkerGlobalScope.instance`
+- `DedicatedWorkerGlobalScope.instance`
+- `ServiceWorkerGlobalScope.instance`
+- `WorkerGlobalScope.instance`
+
+#### `dart:io`
+
+- Added new HTTP status codes.
+
+### Dart for the Web
+
+#### dart2js
+
+- **(Breaking)** Duplicate keys in a const map are not allowed and produce a
+  compile-time error. Dart2js used to report this as a warning before. This was
+  already an error in dartanalyzer and DDC and will be an error in other tools
+  in the future as well.
+
+- Added `-O` flag to tune optimization levels. For more details run
+  `dart2js -h -v`.
+
+  We recommend to enable optimizations using the `-O` flag instead of individual
+  flags for each optimization. This is because the `-O` flag is intended to be
+  stable and continue to work in future versions of dart2js, while individual
+  flags may come and go.
+
+  At this time we recommend to test and debug with `-O1` and to deploy with
+  `-O3`.
+
+### Tool Changes
+
+#### dartfmt
+
+- Addressed several dartfmt issues when used with the new CFE parser.
+
+#### Linter
+
+Bumped the linter to `0.1.70` which includes the following new lints:
+
+- `avoid_returning_null_for_void`
+- `sort_pub_dependencies`
+- `prefer_mixin`
+- `avoid_implementing_value_types`
+- `flutter_style_todos`
+- `avoid_void_async`
+- `prefer_void_to_null`
+
+and improvements:
+
+- Fixed NPE in `prefer_iterable_whereType`.
+- Improved message display for `await_only_futures`
+- Performance improvements for `null_closures`
+- Mixin support
+- Updated `sort_constructors_first` to apply to all members.
+- Updated `unnecessary_this` to work on field initializers.
+- Updated `unawaited_futures` to ignore assignments within cascades.
+- Improved handling of constant expressions with generic type params.
+- NPE fix for `invariant_booleans`.
+- Improved docs for `unawaited_futures`.
+- Updated `unawaited_futures` to check cascades.
+- Relaxed `void_checks` (allowing `T Function()` to be assigned to
+  `void Function()`).
+- Fixed false positives in `lines_longer_than_80_chars`.
+
+#### Pub
+
+- Renamed the `--checked` flag to `pub run` to `--enable-asserts`.
+- Pub will no longer delete directories named "packages".
+- The `--packages-dir` flag is now ignored.
+
+## 2.0.0 - 2018-08-07
+
+This is the first major version release of Dart since 1.0.0, so it contains many
+significant changes across all areas of the platform. Large changes include:
+
+- **(Breaking)** The unsound optional static type system has been replaced with
+  a sound static type system using type inference and runtime checks. This was
+  formerly called "[strong mode][]" and only used by the Dart for web products.
+  Now it is the one official static type system for the entire platform and
+  replaces the previous "checked" and "production" modes.
+
+- **(Breaking)** Functions marked `async` now run synchronously until the first
+  `await` statement. Previously, they would return to the event loop once at the
+  top of the function body before any code runs ([issue 30345][]).
+
+- **(Breaking)** Constants in the core libraries have been renamed from
+  `SCREAMING_CAPS` to `lowerCamelCase`.
+
+- **(Breaking)** Many new methods have been added to core library classes. If
+  you implement the interfaces of these classes, you will need to implement the
+  new methods.
+
+- **(Breaking)** "dart:isolate" and "dart:mirrors" are no longer supported when
+  using Dart for the web. They are still supported in the command-line VM.
+
+- **(Breaking)** Pub's transformer-based build system has been replaced by a
+  [new build system][build system].
+
+- The `new` keyword is optional and can be omitted. Likewise, `const` can be
+  omitted inside a const context ([issue 30921][]).
+
+- Dartium is no longer maintained or supported.
+
+[issue 30345]: https://github.com/dart-lang/sdk/issues/30345
+[issue 30921]: https://github.com/dart-lang/sdk/issues/30921
+[strong mode]: https://dart.dev/guides/language/type-system
+[build system]: https://github.com/dart-lang/build
+
+### Language
+
+- "[Strong mode][]" is now the official type system of the language.
+
+- The `new` keyword is optional and can be omitted. Likewise, `const` can be
+  omitted inside a const context.
+
+- A string in a `part of` declaration may now be used to refer to the library
+  this file is part of. A library part can now declare its library as either:
+
+  ```dart
+  part of name.of.library;
+  ```
+
+  Or:
+
+  ```dart
+  part of "uriReferenceOfLibrary.dart";
+  ```
+
+  This allows libraries with no library declarations (and therefore no name) to
+  have parts, and it allows tools to easily find the library of a part file. The
+  Dart 1.0 syntax is supported but deprecated.
+
+- Functions marked `async` now run synchronously until the first `await`
+  statement. Previously, they would return to the event loop once at the top of
+  the function body before any code runs ([issue 30345][]).
+
+- The type `void` is now a Top type like `dynamic`, and `Object`. It also now
+  has new errors for being used where not allowed (such as being assigned to any
+  non-`void`-typed parameter). Some libraries (importantly, mockito) may need to
+  be updated to accept void values to keep their APIs working.
+
+- Future flattening is now done only as specified in the Dart 2.0 spec, rather
+  than more broadly. This means that the following code has an error on the
+  assignment to `y`.
+
+  ```dart
+  test() {
+    Future<int> f;
+    var x = f.then<Future<List<int>>>((x) => []);
+    Future<List<int>> y = x;
+  }
+  ```
+
+- Invocations of `noSuchMethod()` receive default values for optional args. The
+  following program used to print "No arguments passed", and now prints "First
+  argument is 3".
+
+  ```dart
+  abstract class B {
+    void m([int x = 3]);
+  }
+
+  class A implements B {
+    noSuchMethod(Invocation i) {
+      if (i.positionalArguments.length == 0) {
+        print("No arguments passed");
+      } else {
+        print("First argument is ${i.positionalArguments[0]}");
+      }
+    }
+  }
+
+  void main() {
+    A().m();
+  }
+  ```
+
+- Bounds on generic functions are invariant. The following program now issues an
+  invalid override error ([issue 29014][sdk#29014]):
+
+  ```dart
+  class A {
+    void f<T extends int>() {}
+  }
+
+  class B extends A {
+    @override
+    void f<T extends num>() {}
+  }
+  ```
+
+- Numerous corner case bugs around return statements in synchronous and
+  asynchronous functions fixed. Specifically:
+
+  - Issues [31887][issue 31887], [32881][issue 32881]. Future flattening should
+    not be recursive.
+  - Issues [30638][issue 30638], [32233][issue 32233]. Incorrect downcast errors
+    with `FutureOr`.
+  - Issue [32233][issue 32233]. Errors when returning `FutureOr`.
+  - Issue [33218][issue 33218]. Returns in functions with void related types.
+  - Issue [31278][issue 31278]. Incorrect hint on empty returns in async.
+    functions.
+
+- An empty `return;` in an async function with return type `Future<Object>` does
+  not report an error.
+
+- `return exp;` where `exp` has type `void` in an async function is now an error
+  unless the return type of the function is `void` or `dynamic`.
+
+- Mixed return statements of the form `return;` and `return exp;` are now
+  allowed when `exp` has type `void`.
+
+- A compile time error is emitted for any literal which cannot be exactly
+  represented on the target platform. As a result, dart2js and DDC report errors
+  if an integer literal cannot be represented exactly in JavaScript ([issue
+  33282][]).
+
+- New member conflict rules have been implemented. Most cases of conflicting
+  members with the same name are now static errors ([issue 33235][]).
+
+[sdk#29014]: https://github.com/dart-lang/sdk/issues/29014
+[issue 30638]: https://github.com/dart-lang/sdk/issues/30638
+[issue 31278]: https://github.com/dart-lang/sdk/issues/31278
+[issue 31887]: https://github.com/dart-lang/sdk/issues/31887
+[issue 32233]: https://github.com/dart-lang/sdk/issues/32233
+[issue 32881]: https://github.com/dart-lang/sdk/issues/32881
+[issue 33218]: https://github.com/dart-lang/sdk/issues/33218
+[issue 33235]: https://github.com/dart-lang/sdk/issues/33235
+[issue 33282]: https://github.com/dart-lang/sdk/issues/33282
+[issue 33341]: https://github.com/dart-lang/sdk/issues/33341
+
+### Core libraries
+
+- Replaced `UPPER_CASE` constant names with `lowerCamelCase`. For example,
+  `HTML_ESCAPE` is now `htmlEscape`.
+
+- The Web libraries were re-generated using Chrome 63 WebIDLs ([details][idl]).
+
+[idl]: https://github.com/dart-lang/sdk/wiki/Chrome-63-Dart-Web-Libraries
+
+#### `dart:async`
+
+- `Stream`:
+  - Added `cast` and `castFrom`.
+  - Changed `firstWhere`, `lastWhere`, and `singleWhere` to return `Future<T>`
+    and added an optional `T orElse()` callback.
+- `StreamTransformer`: added `cast` and `castFrom`.
+- `StreamTransformerBase`: new class.
+- `Timer`: added `tick` property.
+- `Zone`
+  - changed to be strong-mode clean. This required some breaking API changes.
+    See https://goo.gl/y9mW2x for more information.
+  - Added `bindBinaryCallbackGuarded`, `bindCallbackGuarded`, and
+    `bindUnaryCallbackGuarded`.
+  - Renamed `Zone.ROOT` to `Zone.root`.
+- Removed the deprecated `defaultValue` parameter on `Stream.firstWhere` and
+  `Stream.lastWhere`.
+- Changed an internal lazily-allocated reusable "null future" to always belong
+  to the root zone. This avoids race conditions where the first access to the
+  future determined which zone it would belong to. The zone is only used for
+  _scheduling_ the callback of listeners, the listeners themselves will run in
+  the correct zone in any case. Issue [#32556](http://dartbug.com/32556).
+
+#### `dart:cli`
+
+- _New_ "provisional" library for CLI-specific features.
+- `waitFor`: function that suspends a stack to wait for a `Future` to complete.
+
+#### `dart:collection`
+
+- `MapBase`: added `mapToString`.
+- `LinkedHashMap` no longer implements `HashMap`
+- `LinkedHashSet` no longer implements `HashSet`.
+- Added `of` constructor to `Queue`, `ListQueue`, `DoubleLinkedQueue`,
+  `HashSet`, `LinkedHashSet`, `SplayTreeSet`, `Map`, `HashMap`, `LinkedHashMap`,
+  `SplayTreeMap`.
+- Removed `Maps` class. Extend `MapBase` or mix in `MapMixin` instead to provide
+  map method implementations for a class.
+- Removed experimental `Document` method `getCSSCanvasContext` and property
+  `supportsCssCanvasContext`.
+- Removed obsolete `Element` property `xtag` no longer supported in browsers.
+- Exposed `ServiceWorker` class.
+- Added constructor to `MessageChannel` and `MessagePort` `addEventListener`
+  automatically calls `start` method to receive queued messages.
+
+#### `dart:convert`
+
+- `Base64Codec.decode` return type is now `Uint8List`.
+- `JsonUnsupportedObjectError`: added `partialResult` property
+- `LineSplitter` now implements `StreamTransformer<String, String>` instead of
+  `Converter`. It retains `Converter` methods `convert` and
+  `startChunkedConversion`.
+- `Utf8Decoder` when compiled with dart2js uses the browser's `TextDecoder` in
+  some common cases for faster decoding.
+- Renamed `ASCII`, `BASE64`, `BASE64URI`, `JSON`, `LATIN1` and `UTF8` to
+  `ascii`, `base64`, `base64Uri`, `json`, `latin1` and `utf8`.
+- Renamed the `HtmlEscapeMode` constants `UNKNOWN`, `ATTRIBUTE`, `SQ_ATTRIBUTE`
+  and `ELEMENT` to `unknown`, `attribute`, `sqAttribute` and `elements`.
+- Added `jsonEncode`, `jsonDecode`, `base64Encode`, `base64UrlEncode` and
+  `base64Decode` top-level functions.
+- Changed return type of `encode` on `AsciiCodec` and `Latin1Codec`, and
+  `convert` on `AsciiEncoder`, `Latin1Encoder`, to `Uint8List`.
+- Allow `utf8.decoder.fuse(json.decoder)` to ignore leading Unicode BOM.
+
+#### `dart:core`
+
+- `BigInt` class added to support integers greater than 64-bits.
+- Deprecated the `proxy` annotation.
+- Added `Provisional` class and `provisional` field.
+- Added `pragma` annotation.
+- `RegExp` added static `escape` function.
+- The `Uri` class now correctly handles paths while running on Node.js on
+  Windows.
+- Core collection changes:
+  - `Iterable` added members `cast`, `castFrom`, `followedBy` and `whereType`.
+  - `Iterable.singleWhere` added `orElse` parameter.
+  - `List` added `+` operator, `first` and `last` setters, and `indexWhere` and
+    `lastIndexWhere` methods, and static `copyRange` and `writeIterable`
+    methods.
+  - `Map` added `fromEntries` constructor.
+  - `Map` added `addEntries`, `cast`, `entries`, `map`, `removeWhere`, `update`
+    and `updateAll` members.
+  - `MapEntry`: new class used by `Map.entries`.
+  - _Note_: if a class extends `IterableBase`, `ListBase`, `SetBase` or
+    `MapBase` (or uses the corresponding mixins) from `dart:collection`, the new
+    members are implemented automatically.
+  - Added `of` constructor to `List`, `Set`, `Map`.
+- Renamed `double.INFINITY`, `double.NEGATIVE_INFINITY`, `double.NAN`,
+  `double.MAX_FINITE` and `double.MIN_POSITIVE` to `double.infinity`,
+  `double.negativeInfinity`, `double.nan`, `double.maxFinite` and
+  `double.minPositive`.
+- Renamed the following constants in `DateTime` to lower case: `MONDAY` through
+  `SUNDAY`, `DAYS_PER_WEEK` (as `daysPerWeek`), `JANUARY` through `DECEMBER` and
+  `MONTHS_PER_YEAR` (as `monthsPerYear`).
+- Renamed the following constants in `Duration` to lower case:
+  `MICROSECONDS_PER_MILLISECOND` to `microsecondsPerMillisecond`,
+  `MILLISECONDS_PER_SECOND` to `millisecondsPerSecond`, `SECONDS_PER_MINUTE` to
+  `secondsPerMinute`, `MINUTES_PER_HOUR` to `minutesPerHour`, `HOURS_PER_DAY` to
+  `hoursPerDay`, `MICROSECONDS_PER_SECOND` to `microsecondsPerSecond`,
+  `MICROSECONDS_PER_MINUTE` to `microsecondsPerMinute`, `MICROSECONDS_PER_HOUR`
+  to `microsecondsPerHour`, `MICROSECONDS_PER_DAY` to `microsecondsPerDay`,
+  `MILLISECONDS_PER_MINUTE` to `millisecondsPerMinute`, `MILLISECONDS_PER_HOUR`
+  to `millisecondsPerHour`, `MILLISECONDS_PER_DAY` to `millisecondsPerDay`,
+  `SECONDS_PER_HOUR` to `secondsPerHour`, `SECONDS_PER_DAY` to `secondsPerDay`,
+  `MINUTES_PER_DAY` to `minutesPerDay`, and `ZERO` to `zero`.
+- Added `typeArguments` to `Invocation` class.
+- Added constructors to invocation class that allows creation of `Invocation`
+  objects directly, without going through `noSuchMethod`.
+- Added `unaryMinus` and `empty` constant symbols on the `Symbol` class.
+- Changed return type of `UriData.dataAsBytes` to `Uint8List`.
+- Added `tryParse` static method to `int`, `double`, `num`, `BigInt`, `Uri` and
+  `DateTime`.
+- Deprecated `onError` parameter on `int.parse`, `double.parse` and `num.parse`.
+- Deprecated the `NoSuchMethodError` constructor.
+- `int.parse` on the VM no longer accepts unsigned hexadecimal numbers greater
+  than or equal to `2**63` when not prefixed by `0x`. (SDK issue
+  [32858](https://github.com/dart-lang/sdk/issues/32858))
+
+#### `dart:developer`
+
+- `Flow` class added.
+- `Timeline.startSync` and `Timeline.timeSync` now accepts an optional parameter
+  `flow` of type `Flow`. The `flow` parameter is used to generate flow timeline
+  events that are enclosed by the slice described by
+  `Timeline.{start,finish}Sync` and `Timeline.timeSync`.
+
+<!--
+Still need entries for all changes to dart:html since 1.x
+-->
+
+#### `dart:html`
+
+- Removed deprecated `query` and `queryAll`. Use `querySelector` and
+  `querySelectorAll`.
+
+#### `dart:io`
+
+- `HttpStatus` added `UPGRADE_REQUIRED`.
+- `IOOverrides` and `HttpOverrides` added to aid in writing tests that wish to
+  mock varios `dart:io` objects.
+- `Platform.operatingSystemVersion` added that gives a platform-specific String
+  describing the version of the operating system.
+- `ProcessStartMode.INHERIT_STDIO` added, which allows a child process to
+  inherit the parent's stdio handles.
+- `RawZLibFilter` added for low-level access to compression and decompression
+  routines.
+- Unified backends for `SecureSocket`, `SecurityContext`, and `X509Certificate`
+  to be consistent across all platforms. All `SecureSocket`, `SecurityContext`,
+  and `X509Certificate` properties and methods are now supported on iOS and OSX.
+- `SecurityContext.alpnSupported` deprecated as ALPN is now supported on all
+  platforms.
+- `SecurityContext`: added `withTrustedRoots` named optional parameter
+  constructor, which defaults to false.
+- Added a `timeout` parameter to `Socket.connect`, `RawSocket.connect`,
+  `SecureSocket.connect` and `RawSecureSocket.connect`. If a connection attempt
+  takes longer than the duration specified in `timeout`, a `SocketException`
+  will be thrown. Note: if the duration specified in `timeout` is greater than
+  the OS level timeout, a timeout may occur sooner than specified in `timeout`.
+- `Stdin.hasTerminal` added, which is true if stdin is attached to a terminal.
+- `WebSocket` added static `userAgent` property.
+- `RandomAccessFile.close` returns `Future<void>`
+- Added `IOOverrides.socketConnect`.
+- Added Dart-styled constants to `ZLibOptions`, `FileMode`, `FileLock`,
+  `FileSystemEntityType`, `FileSystemEvent`, `ProcessStartMode`,
+  `ProcessSignal`, `InternetAddressType`, `InternetAddress`, `SocketDirection`,
+  `SocketOption`, `RawSocketEvent`, and `StdioType`, and deprecated the old
+  `SCREAMING_CAPS` constants.
+- Added the Dart-styled top-level constants `zlib`, `gzip`, and
+  `systemEncoding`, and deprecated the old `SCREAMING_CAPS` top-level constants.
+- Removed the top-level `FileMode` constants `READ`, `WRITE`, `APPEND`,
+  `WRITE_ONLY`, and `WRITE_ONLY_APPEND`. Please use e.g. `FileMode.read`
+  instead.
+- Added `X509Certificate.der`, `X509Certificate.pem`, and
+  `X509Certificate.sha1`.
+- Added `FileSystemEntity.fromRawPath` constructor to allow for the creation of
+  `FileSystemEntity` using `Uint8List` buffers.
+- Dart-styled constants have been added for `HttpStatus`, `HttpHeaders`,
+  `ContentType`, `HttpClient`, `WebSocketStatus`, `CompressionOptions`, and
+  `WebSocket`. The `SCREAMING_CAPS` constants are marked deprecated. Note that
+  `HttpStatus.CONTINUE` is now `HttpStatus.continue_`, and that e.g.
+  `HttpHeaders.FIELD_NAME` is now `HttpHeaders.fieldNameHeader`.
+- Deprecated `Platform.packageRoot`, which is only used for `packages/`
+  directory resolution which is no longer supported. It will now always return
+  null, which is a value that was always possible for it to return previously.
+- Adds `HttpClient.connectionTimeout`.
+- Adds `{Socket,RawSocket,SecureSocket}.startConnect`. These return a
+  `ConnectionTask`, which can be used to cancel an in-flight connection attempt.
+
+#### `dart:isolate`
+
+- Make `Isolate.spawn` take a type parameter representing the argument type of
+  the provided function. This allows functions with arguments types other than
+  `Object` in strong mode.
+- Rename `IMMEDIATE` and `BEFORE_NEXT_EVENT` on `Isolate` to `immediate` and
+  `beforeNextEvent`.
+- Deprecated `Isolate.packageRoot`, which is only used for `packages/` directory
+  resolution which is no longer supported. It will now always return null, which
+  is a value that was always possible for it to return previously.
+- Deprecated `packageRoot` parameter in `Isolate.spawnUri`, which is was
+  previously used only for `packages/` directory resolution. That style of
+  resolution is no longer supported in Dart 2.
+
+<!--
+Still need entries for all changes to dart:js since 1.x
+-->
+
+#### `dart.math`
+
+- Renamed `E`, `LN10`, `LN`, `LOG2E`, `LOG10E`, `PI`, `SQRT1_2` and `SQRT2` to
+  `e`, `ln10`, `ln`, `log2e`, `log10e`, `pi`, `sqrt1_2` and `sqrt2`.
+
+#### `dart.mirrors`
+
+- Added `IsolateMirror.loadUri`, which allows dynamically loading additional
+  code.
+- Marked `MirrorsUsed` as deprecated. The `MirrorsUsed` annotation was only used
+  to inform the dart2js compiler about how mirrors were used, but dart2js no
+  longer supports the mirrors library altogether.
+
+<!--
+Still need entries for all changes to dart:svg since 1.x
+-->
+
+#### `dart:typed_data`
+
+- Added `Unmodifiable` view classes over all `List` types.
+- Renamed `BYTES_PER_ELEMENT` to `bytesPerElement` on all typed data lists.
+- Renamed constants `XXXX` through `WWWW` on `Float32x4` and `Int32x4` to
+  lower-case `xxxx` through `wwww`.
+- Renamed `Endinanness` to `Endian` and its constants from `BIG_ENDIAN`,
+  `LITTLE_ENDIAN` and `HOST_ENDIAN` to `little`, `big` and `host`.
+
+<!--
+Still need entries for all changes to dart:web_audio,web_gl,web_sql since 1.x
+-->
+
+### Dart VM
+
+- Support for MIPS has been removed.
+
+- Dart `int` is now restricted to 64 bits. On overflow, arithmetic operations
+  wrap around, and integer literals larger than 64 bits are not allowed. See
+  https://github.com/dart-lang/sdk/blob/main/docs/language/informal/int64.md
+  for details.
+
+- The Dart VM no longer attempts to perform `packages/` directory resolution
+  (for loading scripts, and in `Isolate.resolveUri`). Users relying on
+  `packages/` directories should switch to `.packages` files.
+
+### Dart for the Web
+
+- Expose JavaScript Promise APIs using Dart futures. For example,
+  `BackgroundFetchManager.get` is defined as:
+
+  ```dart
+    Future<BackgroundFetchRegistration> get(String id)
+  ```
+
+  It can be used like:
+
+  ```dart
+  BackgroundFetchRegistration result = await fetchMgr.get('abc');
+  ```
+
+  The underlying JS Promise-to-Future mechanism will be exposed as a public API
+  in the future.
+
+#### Dart Dev Compiler (DDC)
+
+- dartdevc will no longer throw an error from `is` checks that return a
+  different result in weak mode (SDK [issue 28988][sdk#28988]). For example:
+
+  ```dart
+  main() {
+    List l = [];
+    // Prints "false", does not throw.
+    print(l is List<String>);
+  }
+  ```
+
+- Failed `as` casts on `Iterable<T>`, `Map<T>`, `Future<T>`, and `Stream<T>` are
+  no longer ignored. These failures were ignored to make it easier to migrate
+  Dart 1 code to strong mode, but ignoring them is a hole in the type system.
+  This closes part of that hole. (We still need to stop ignoring "as" cast
+  failures on function types, and implicit cast failures on the above types and
+  function types.)
+
+[sdk#28988]: https://github.com/dart-lang/sdk/issues/28988
+
+#### dart2js
+
+- dart2js now compiles programs with Dart 2.0 semantics. Apps are expected to be
+  bigger than before, because Dart 2.0 has many more implicit checks (similar to
+  the `--checked` flag in Dart 1.0).
+
+  We exposed a `--omit-implicit-checks` flag which removes most of the extra
+  implicit checks. Only use this if you have enough test coverage to know that
+  the app will work well without the checks. If a check would have failed and it
+  is omitted, your app may crash or behave in unexpected ways. This flag is
+  similar to `--trust-type-annotations` in Dart 1.0.
+
+- dart2js replaced its front-end with the common front-end (CFE). Thanks to the
+  CFE, dart2js errors are more consistent with all other Dart tools.
+
+- dart2js replaced its source-map implementation. There aren't any big
+  differences, but more data is emitted for synthetic code generated by the
+  compiler.
+
+- `dart:mirrors` support was removed. Frameworks are encouraged to use
+  code-generation instead. Conditional imports indicate that mirrors are not
+  supported, and any API in the mirrors library will throw at runtime.
+
+- The generated output of dart2js can now be run as a webworker.
+
+- `dart:isolate` support was removed. To launch background tasks, please use
+  webworkers instead. APIs for webworkers can be accessed from `dart:html` or
+  JS-interop.
+
+- dart2js no longer supports the `--package-root` flag. This flag was deprecated
+  in favor of `--packages` long ago.
+
+### Tool Changes
+
+#### Analyzer
+
+- The analyzer will no longer issue a warning when a generic type parameter is
+  used as the type in an instance check. For example:
+
+  ```dart
+  test<T>() {
+    print(3 is T); // No warning
+  }
+  ```
+
+- New static checking of `@visibleForTesting` elements. Accessing a method,
+  function, class, etc. annotated with `@visibleForTesting` from a file _not_ in
+  a `test/` directory will result in a new hint ([issue 28273][]).
+
+- Static analysis now respects functions annotated with `@alwaysThrows` ([issue
+  31384][]).
+
+- New hints added:
+
+  - `NULL_AWARE_BEFORE_OPERATOR` when an operator is used after a null-aware
+    access. For example:
+
+    ```dart
+    x?.a - ''; // HINT
+    ```
+
+  - `NULL_AWARE_IN_LOGICAL_OPERATOR` when an expression with null-aware access
+    is used as a condition in logical operators. For example:
+
+    ```dart
+    x.a || x?.b; // HINT
+    ```
+
+- The command line analyzer (dartanalyzer) and the analysis server no longer
+  treat directories named `packages` specially. Previously they had ignored
+  these directories - and their contents - from the point of view of analysis.
+  Now they'll be treated just as regular directories. This special-casing of
+  `packages` directories was to support using symlinks for package: resolution;
+  that functionality is now handled by `.packages` files.
+
+- New static checking of duplicate shown or hidden names in an export directive
+  ([issue 33182][]).
+
+- The analysis server will now only analyze code in Dart 2 mode ('strong mode').
+  It will emit warnings for analysis options files that have
+  `strong-mode: false` set (and will emit a hint for `strong-mode: true`, which
+  is no longer necessary).
+
+- The dartanalyzer `--strong` flag is now deprecated and ignored. The
+  command-line analyzer now only analyzes code in strong mode.
+
+[issue 28273]: https://github.com/dart-lang/sdk/issues/28273
+[issue 31384]: https://github.com/dart-lang/sdk/issues/31384
+[issue 33182]: https://github.com/dart-lang/sdk/issues/33182
+
+#### dartfmt
+
+- Support `assert()` in const constructor initializer lists.
+
+- Better formatting for multi-line strings in argument lists.
+
+- Force splitting an empty block as the then body of an if with an else.
+
+- Support metadata annotations on enum cases.
+
+- Add `--fix` to remove unneeded `new` and `const` keywords, and change `:` to
+  `=` before named parameter default values.
+
+- Change formatting rules around static methods to uniformly format code with
+  and without `new` and `const`.
+
+- Format expressions inside string interpolation.
+
+#### Pub
+
+- Pub has a brand new version solver! It supports all the same features as the
+  old version solver, but it's much less likely to stall out on difficult
+  package graphs, and it's much clearer about why a solution can't be found when
+  version solving fails.
+
+- Remove support for transformers, `pub build`, and `pub serve`. Use the [new
+  build system][transformers] instead.
+
+- There is now a default SDK constraint of `<2.0.0` for any package with no
+  existing upper bound. This allows us to move more safely to 2.0.0. All new
+  packages published on pub will now require an upper bound SDK constraint so
+  future major releases of Dart don't destabilize the package ecosystem.
+
+  All SDK constraint exclusive upper bounds are now treated as though they allow
+  pre-release versions of that upper bound. For example, the SDK constraint
+  `>=1.8.0 <2.0.0` now allows pre-release SDK versions such as `2.0.0-beta.3.0`.
+  This allows early adopters to try out packages that don't explicitly declare
+  support for the new version yet. You can disable this functionality by setting
+  the `PUB_ALLOW_PRERELEASE_SDK` environment variable to `false`.
+
+- Allow depending on a package in a subdirectory of a Git repository. Git
+  dependencies may now include a `path` parameter, indicating that the package
+  exists in a subdirectory of the Git repository. For example:
+
+  ```yaml
+  dependencies:
+    foobar:
+      git:
+        url: git://github.com/dart-lang/multi_package_repo
+        path: pkg/foobar
+  ```
+
+- Added an `--executables` option to `pub deps` command. This will list all
+  available executables that can be run with `pub run`.
+
+- The Flutter `sdk` source will now look for packages in
+  `flutter/bin/cache/pkg/` as well as `flutter/packages/`. In particular, this
+  means that packages can depend on the `sky_engine` package from the `sdk`
+  source ([issue 1775][pub#1775]).
+
+- Pub now caches compiled packages and snapshots in the `.dart_tool/pub`
+  directory, rather than the `.pub` directory ([issue 1795][pub#1795]).
+
+- Other bug fixes and improvements.
+
+[issue 30246]: https://github.com/dart-lang/sdk/issues/30246
+[pub#1679]: https://github.com/dart-lang/pub/issues/1679
+[pub#1684]: https://github.com/dart-lang/pub/issues/1684
+[pub#1775]: https://github.com/dart-lang/pub/issues/1775
+[pub#1795]: https://github.com/dart-lang/pub/issues/1795
+[pub#1823]: https://github.com/dart-lang/pub/issues/1823
+
+## 1.24.3 - 2017-12-14
+
+- Fix for constructing a new SecurityContext that contains the built-in
+  certificate authority roots
+  ([issue 24693](https://github.com/dart-lang/sdk/issues/24693)).
+
+### Core library changes
+
+- `dart:io`
+  - Unified backends for `SecureSocket`, `SecurityContext`, and
+    `X509Certificate` to be consistent across all platforms. All `SecureSocket`,
+    `SecurityContext`, and `X509Certificate` properties and methods are now
+    supported on iOS and OSX.
+
+## 1.24.2 - 2017-06-22
+
+- Fixes for debugging in Dartium.
+  - Fix DevConsole crash with JS
+    ([issue 29873](https://github.com/dart-lang/sdk/issues/29873)).
+  - Fix debugging in WebStorm, NULL returned for JS objects
+    ([issue 29854](https://github.com/dart-lang/sdk/issues/29854)).
+
+## 1.24.1 - 2017-06-14
+
+- Bug fixes for dartdevc support in `pub serve`.
+  - Fixed module config invalidation logic so modules are properly recalculated
+    when package layout changes.
+  - Fixed exception when handling require.js errors that aren't script load
+    errors.
+  - Fixed an issue where requesting the bootstrap.js file before the dart.js
+    file would result in a 404.
+  - Fixed a Safari issue during bootstrapping (note that Safari is still not
+    officially supported but does work for trivial examples).
+- Fix for a Dartium issue where there was no sound in checked mode
+  ([issue 29810](https://github.com/dart-lang/sdk/issues/29810)).
+
+## 1.24.0 - 2017-06-12
+
+### Language
+
+- During a dynamic type check, `void` is not required to be `null` anymore. In
+  practice, this makes overriding `void` functions with non-`void` functions
+  safer.
+
+- During static analysis, a function or setter declared using `=>` with return
+  type `void` now allows the returned expression to have any type. For example,
+  assuming the declaration `int x;`, it is now type correct to have
+  `void f() => ++x;`.
+
+- A new function-type syntax has been added to the language. **Warning**: _In
+  Dart 1.24, this feature is incomplete, and not stable in the Analyzer._
+
+  Intuitively, the type of a function can be constructed by textually replacing
+  the function's name with `Function` in its declaration. For instance, the type
+  of `void foo() {}` would be `void Function()`. The new syntax may be used
+  wherever a type can be written. It is thus now possible to declare fields
+  containing functions without needing to write typedefs: `void Function() x;`.
+  The new function type has one restriction: it may not contain the old-style
+  function-type syntax for its parameters. The following is thus illegal:
+  `void Function(int f())`. `typedefs` have been updated to support this new
+  syntax.
+
+  Examples:
+
+  ```dart
+  typedef F = void Function();  // F is the name for a `void` callback.
+  int Function(int) f;  // A field `f` that contains an int->int function.
+
+  class A<T> {
+    // The parameter `callback` is a function that takes a `T` and returns
+    // `void`.
+    void forEach(void Function(T) callback);
+  }
+
+  // The new function type supports generic arguments.
+  typedef Invoker = T Function<T>(T Function() callback);
+  ```
+
+### Core library changes
+
+- `dart:async`, `dart:core`, `dart:io`
+
+  - Adding to a closed sink, including `IOSink`, is no longer not allowed. In
+    1.24, violations are only reported (on stdout or stderr), but a future
+    version of the Dart SDK will change this to throwing a `StateError`.
+
+- `dart:convert`
+
+  - **BREAKING** Removed the deprecated `ChunkedConverter` class.
+  - JSON maps are now typed as `Map<String, dynamic>` instead of
+    `Map<dynamic, dynamic>`. A JSON-map is not a `HashMap` or `LinkedHashMap`
+    anymore (but just a `Map`).
+
+- `dart:io`
+
+  - Added `Platform.localeName`, needed for accessing the locale on platforms
+    that don't store it in an environment variable.
+  - Added `ProcessInfo.currentRss` and `ProcessInfo.maxRss` for inspecting the
+    Dart VM process current and peak resident set size.
+  - Added `RawSynchronousSocket`, a basic synchronous socket implementation.
+
+- `dart:` web APIs have been updated to align with Chrome v50. This change
+  includes **a large number of changes**, many of which are breaking. In some
+  cases, new class names may conflict with names that exist in existing code.
+
+- `dart:html`
+
+  - **REMOVED** classes: `Bluetooth`, `BluetoothDevice`,
+    `BluetoothGattCharacteristic`, `BluetoothGattRemoteServer`,
+    `BluetoothGattService`, `BluetoothUuid`, `CrossOriginConnectEvent`,
+    `DefaultSessionStartEvent`, `DomSettableTokenList`, `MediaKeyError`,
+    `PeriodicSyncEvent`, `PluginPlaceholderElement`, `ReadableStream`,
+    `StashedMessagePort`, `SyncRegistration`
+
+  - **REMOVED** members:
+
+    - `texImage2DCanvas` was removed from `RenderingContext`.
+    - `endClip` and `startClip` were removed from `Animation`.
+    - `after` and `before` were removed from `CharacterData`, `ChildNode` and
+      `Element`.
+    - `keyLocation` was removed from `KeyboardEvent`. Use `location` instead.
+    - `generateKeyRequest`, `keyAddedEvent`, `keyErrorEvent`, `keyMessageEvent`,
+      `mediaGroup`, `needKeyEvent`, `onKeyAdded`, `onKeyError`, `onKeyMessage`,
+      and `onNeedKey` were removed from `MediaElement`.
+    - `getStorageUpdates` was removed from `Navigator`
+    - `status` was removed from `PermissionStatus`
+    - `getAvailability` was removed from `PreElement`
+
+  - Other behavior changes:
+    - URLs returned in CSS or html are formatted with quoted string. Like
+      `url("http://google.com")` instead of `url(http://google.com)`.
+    - Event timestamp property type changed from `int` to `num`.
+    - Chrome introduced slight layout changes of UI objects. In addition many
+      height/width dimensions are returned in subpixel values (`num` instead of
+      whole numbers).
+    - `setRangeText` with a `selectionMode` value of 'invalid' is no longer
+      valid. Only "select", "start", "end", "preserve" are allowed.
+
+- `dart:svg`
+
+  - A large number of additions and removals. Review your use of `dart:svg`
+    carefully.
+
+- `dart:web_audio`
+
+  - new method on `AudioContext` - `createIirFilter` returns a new class
+    `IirFilterNode`.
+
+- `dart:web_gl`
+
+  - new classes: `CompressedTextureAstc`, `ExtColorBufferFloat`,
+    `ExtDisjointTimerQuery`, and `TimerQueryExt`.
+
+  - `ExtFragDepth` added: `readPixels2` and `texImage2D2`.
+
+#### Strong Mode
+
+- Removed ad hoc `Future.then` inference in favor of using `FutureOr`. Prior to
+  adding `FutureOr` to the language, the analyzer implemented an ad hoc type
+  inference for `Future.then` (and overrides) treating it as if the onValue
+  callback was typed to return `FutureOr` for the purposes of inference. This ad
+  hoc inference has been removed now that `FutureOr` has been added.
+
+  Packages that implement `Future` must either type the `onValue` parameter to
+  `.then` as returning `FutureOr<T>`, or else must leave the type of the
+  parameter entirely to allow inference to fill in the type.
+
+- During static analysis, a function or setter declared using `=>` with return
+  type `void` now allows the returned expression to have any type.
+
+### Tool Changes
+
+- Dartium
+
+  Dartium is now based on Chrome v50. See _Core library changes_ above for
+  details on the changed APIs.
+
+- Pub
+
+  - `pub build` and `pub serve`
+
+    - Added support for the Dart Development Compiler.
+
+      Unlike dart2js, this new compiler is modular, which allows pub to do
+      incremental re-builds for `pub serve`, and potentially `pub build` in the
+      future.
+
+      In practice what that means is you can edit your Dart files, refresh in
+      Chrome (or other supported browsers), and see your edits almost
+      immediately. This is because pub is only recompiling your package, not all
+      packages that you depend on.
+
+      There is one caveat with the new compiler, which is that your package and
+      your dependencies must all be strong mode clean. If you are getting an
+      error compiling one of your dependencies, you will need to file bugs or
+      send pull requests to get them strong mode clean.
+
+      There are two ways of opting into the new compiler:
+
+      - Use the new `--web-compiler` flag, which supports `dartdevc`, `dart2js`
+        or `none` as options. This is the easiest way to try things out without
+        changing the default.
+
+      - Add config to your pubspec. There is a new `web` key which supports a
+        single key called `compiler`. This is a map from mode names to compiler
+        to use. For example, to default to dartdevc in debug mode you can add
+        the following to your pubspec:
+
+        ```yaml
+        web:
+          compiler:
+            debug: dartdevc
+        ```
+
+      You can also use the new compiler to run your tests in Chrome much more
+      quickly than you can with dart2js. In order to do that, run
+      `pub serve test --web-compiler=dartdevc`, and then run
+      `pub run test -p chrome --pub-serve=8080`.
+
+    - The `--no-dart2js` flag has been deprecated in favor of
+      `--web-compiler=none`.
+
+    - `pub build` will use a failing exit code if there are errors in any
+      transformer.
+
+  - `pub publish`
+
+    - Added support for the UNLICENSE file.
+
+    - Packages that depend on the Flutter SDK may be published.
+
+  - `pub get` and `pub upgrade`
+
+    - Don't dump a stack trace when a network error occurs while fetching
+      packages.
+
+- dartfmt
+  - Preserve type parameters in new generic function typedef syntax.
+  - Add self-test validation to ensure formatter bugs do not cause user code to
+    be lost.
+
+### Infrastructure changes
+
+- As of this release, we'll show a warning when using the MIPS architecture.
+  Unless we learn about any critical use of Dart on MIPS in the meantime, we're
+  planning to deprecate support for MIPS starting with the next stable release.
+
+## 1.23.0 - 2017-04-21
+
+#### Strong Mode
+
+- Breaking change - it is now a strong mode error if a mixin causes a name
+  conflict between two private members (field/getter/setter/method) from a
+  different library. (SDK issue
+  [28809](https://github.com/dart-lang/sdk/issues/28809)).
+
+lib1.dart:
+
+```dart
+class A {
+  int _x;
+}
+
+class B {
+  int _x;
+}
+```
+
+lib2.dart:
+
+```dart
+import 'lib1.dart';
+
+class C extends A with B {}
+```
+
+```
+    error • The private name _x, defined by B, conflicts with the same name defined by A at tmp/lib2.dart:3:24 • private_collision_in_mixin_application
+```
+
+- Breaking change - strong mode will prefer the expected type to infer generic
+  types, functions, and methods (SDK issue
+  [27586](https://github.com/dart-lang/sdk/issues/27586)).
+
+  ```dart
+  main() {
+    List<Object> foo = /*infers: <Object>*/['hello', 'world'];
+    var bar = /*infers: <String>*/['hello', 'world'];
+  }
+  ```
+
+- Strong mode inference error messages are improved (SDK issue
+  [29108](https://github.com/dart-lang/sdk/issues/29108)).
+
+  ```dart
+  import 'dart:math';
+  test(Iterable/* fix is to add <num> here */ values) {
+    num n = values.fold(values.first as num, max);
+  }
+  ```
+
+  Now produces the error on the generic function "max":
+
+  ```
+  Couldn't infer type parameter 'T'.
+
+  Tried to infer 'dynamic' for 'T' which doesn't work:
+    Function type declared as '<T extends num>(T, T) → T'
+                  used where  '(num, dynamic) → num' is required.
+
+  Consider passing explicit type argument(s) to the generic.
+  ```
+
+- Strong mode supports overriding fields, `@virtual` is no longer required (SDK
+  issue [28120](https://github.com/dart-lang/sdk/issues/28120)).
+
+  ```dart
+  class C {
+    int x = 42;
+  }
+  class D extends C {
+    get x {
+      print("x got called");
+      return super.x;
+    }
+  }
+  main() {
+    print(new D().x);
+  }
+  ```
+
+- Strong mode down cast composite warnings are no longer issued by default. (SDK
+  issue [28588](https://github.com/dart-lang/sdk/issues/28588)).
+
+```dart
+void test() {
+  List untyped = [];
+  List<int> typed = untyped; // No down cast composite warning
+}
+```
+
+To opt back into the warnings, add the following to the
+[.analysis_options](https://dart.dev/guides/language/analysis-options)
+file for your project.
+
+```
+analyzer:
+  errors:
+    strong_mode_down_cast_composite: warning
+```
+
+### Core library changes
+
+- `dart:core`
+  - Added `Uri.isScheme` function to check the scheme of a URI. Example:
+    `uri.isScheme("http")`. Ignores case when comparing.
+  - Make `UriData.parse` validate its input better. If the data is base-64
+    encoded, the data is normalized wrt. alphabet and padding, and it contains
+    invalid base-64 data, parsing fails. Also normalizes non-base-64 data.
+- `dart:io`
+  - Added functions `File.lastAccessed`, `File.lastAccessedSync`,
+    `File.setLastModified`, `File.setLastModifiedSync`, `File.setLastAccessed`,
+    and `File.setLastAccessedSync`.
+  - Added `{Stdin,Stdout}.supportsAnsiEscapes`.
+
+### Dart VM
+
+- Calls to `print()` and `Stdout.write*()` now correctly print unicode
+  characters to the console on Windows. Calls to `Stdout.add*()` behave as
+  before.
+
+### Tool changes
+
+- Analysis
+
+  - `dartanalyzer` now follows the same rules as the analysis server to find an
+    analysis options file, stopping when an analysis options file is found:
+    - Search up the directory hierarchy looking for an analysis options file.
+    - If analyzing a project referencing the [Flutter](https://flutter.io/)
+      package, then use the
+      [default Flutter analysis options](https://github.com/flutter/flutter/blob/master/packages/flutter/lib/analysis_options_user.yaml)
+      found in `package:flutter`.
+    - If in a Bazel workspace, then use the analysis options in
+      `package:dart.analysis_options/default.yaml` if it exists.
+    - Use the default analysis options rules.
+  - In addition, specific to `dartanalyzer`:
+    - an analysis options file can be specified on the command line via
+      `--options` and that file will be used instead of searching for an
+      analysis options file.
+    - any analysis option specified on the command line (e.g. `--strong` or
+      `--no-strong`) takes precedence over any corresponding value specified in
+      the analysis options file.
+
+- Dartium, dart2js, and DDC
+
+  - Imports to `dart:io` are allowed, but the imported library is not supported
+    and will likely fail on most APIs at runtime. This change was made as a
+    stopgap measure to make it easier to write libraries that share code between
+    platforms (like package `http`). This might change again when configuration
+    specific imports are supported.
+
+- Pub
+
+  - Now sends telemetry data to `pub.dartlang.org` to allow better understanding
+    of why a particular package is being accessed.
+  - `pub publish`
+    - Warns if a package imports a package that's not a dependency from within
+      `lib/` or `bin/`, or a package that's not a dev dependency from within
+      `benchmark/`, `example/`, `test/` or `tool/`.
+    - No longer produces "UID too large" errors on OS X. All packages are now
+      uploaded with the user and group names set to "pub".
+    - No longer fails with a stack overflow when uploading a package that uses
+      Git submodules.
+  - `pub get` and `pub upgrade`
+    - Produce more informative error messages if they're run directly in a
+      package that uses Flutter.
+    - Properly unlock SDK and path dependencies if they have a new version
+      that's also valid according to the user's pubspec.
+
+- dartfmt
+  - Support new generic function typedef syntax.
+  - Make the precedence of cascades more visible.
+  - Fix a couple of places where spurious newlines were inserted.
+  - Correctly report unchanged formatting when reading from stdin.
+  - Ensure space between `-` and `--`. Code that does this is pathological, but
+    it technically meant dartfmt could change the semantics of the code.
+  - Preserve a blank line between enum cases.
+  - Other small formatting tweaks.
+
+## 1.22.1 - 2017-02-22
+
+Patch release, resolves two issues:
+
+- Dart VM crash: [Issue 28072](https://github.com/dart-lang/sdk/issues/28757)
+
+- Dart VM bug combining types, await, and deferred loading:
+  [Issue 28678](https://github.com/dart-lang/sdk/issues/28678)
+
+## 1.22.0 - 2017-02-14
+
+### Language
+
+- Breaking change:
+  ['Generalized tear-offs'](https://github.com/gbracha/generalizedTearOffs/blob/master/proposal.md)
+  are no longer supported, and will cause errors. We updated the language spec
+  and added warnings in 1.21, and are now taking the last step to fully
+  de-support them. They were previously only supported in the VM, and there are
+  almost no known uses of them in the wild.
+
+- The `assert()` statement has been expanded to support an optional second
+  `message` argument (SDK issue
+  [27342](https://github.com/dart-lang/sdk/issues/27342)).
+
+  The message is displayed if the assert fails. It can be any object, and it is
+  accessible as `AssertionError.message`. It can be used to provide more user
+  friendly exception outputs. As an example, the following assert:
+
+  ```dart
+  assert(configFile != null, "Tool config missing. Please see https://goo.gl/k8iAi for details.");
+  ```
+
+  would produce the following exception output:
+
+  ```
+  Unhandled exception:
+  'file:///Users/mit/tmp/tool/bin/main.dart': Failed assertion: line 9 pos 10:
+  'configFile != null': Tool config missing. Please see https://goo.gl/k8iAi for details.
+  #0      _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:33)
+  #1      _AssertionError._throwNew (dart:core-patch/errors_patch.dart:29)
+  #2      main (file:///Users/mit/tmp/tool/bin/main.dart:9:10)
+  ```
+
+- The `Null` type has been moved to the bottom of the type hierarchy. As such,
+  it is considered a subtype of every other type. The `null` _literal_ was
+  always treated as a bottom type. Now the named class `Null` is too:
+
+  ```dart
+  const empty = <Null>[];
+
+  String concatenate(List<String> parts) => parts.join();
+  int sum(List<int> numbers) => numbers.fold(0, (sum, n) => sum + n);
+
+  concatenate(empty); // OK.
+  sum(empty); // OK.
+  ```
+
+- Introduce `covariant` modifier on parameters. It indicates that the parameter
+  (and the corresponding parameter in any method that overrides it) has looser
+  override rules. In strong mode, these require a runtime type check to maintain
+  soundness, but enable an architectural pattern that is useful in some code.
+
+  It lets you specialize a family of classes together, like so:
+
+  ```dart
+  abstract class Predator {
+    void chaseAndEat(covariant Prey p);
+  }
+
+  abstract class Prey {}
+
+  class Mouse extends Prey {}
+
+  class Seal extends Prey {}
+
+  class Cat extends Predator {
+    void chaseAndEat(Mouse m) => ...
+  }
+
+  class Orca extends Predator {
+    void chaseAndEat(Seal s) => ...
+  }
+  ```
+
+  This isn't statically safe, because you could do:
+
+  ```dart
+  Predator predator = new Cat(); // Upcast.
+  predator.chaseAndEat(new Seal()); // Cats can't eat seals!
+  ```
+
+  To preserve soundness in strong mode, in the body of a method that uses a
+  covariant override (here, `Cat.chaseAndEat()`), the compiler automatically
+  inserts a check that the parameter is of the expected type. So the compiler
+  gives you something like:
+
+  ```dart
+  class Cat extends Predator {
+    void chaseAndEat(o) {
+      var m = o as Mouse;
+      ...
+    }
+  }
+  ```
+
+  Spec mode allows this unsound behavior on all parameters, even though users
+  rarely rely on it. Strong mode disallowed it initially. Now, strong mode lets
+  you opt into this behavior in the places where you do want it by using this
+  modifier. Outside of strong mode, the modifier is ignored.
+
+- Change instantiate-to-bounds rules for generic type parameters when running in
+  strong mode. If you leave off the type parameters from a generic type, we need
+  to decide what to fill them in with. Dart 1.0 says just use `dynamic`, but
+  that isn't sound:
+
+  ```dart
+  class Abser<T extends num> {
+     void absThis(T n) { n.abs(); }
+  }
+
+  var a = new Abser(); // Abser<dynamic>.
+  a.absThis("not a num");
+  ```
+
+  We want the body of `absThis()` to be able to safely assume `n` is at least a
+  `num` -- that's why there's a constraint on T, after all. Implicitly using
+  `dynamic` as the type parameter in this example breaks that.
+
+  Instead, strong mode uses the bound. In the above example, it fills it in with
+  `num`, and then the second line where a string is passed becomes a static
+  error.
+
+  However, there are some cases where it is hard to figure out what that default
+  bound should be:
+
+  ```dart
+  class RuhRoh<T extends Comparable<T>> {}
+  ```
+
+  Strong mode's initial behavior sometimes produced surprising, unintended
+  results. For 1.22, we take a simpler approach and then report an error if a
+  good default type argument can't be found.
+
+### Core libraries
+
+- Define `FutureOr<T>` for code that works with either a future or an immediate
+  value of some type. For example, say you do a lot of text manipulation, and
+  you want a handy function to chain a bunch of them:
+
+  ```dart
+  typedef String StringSwizzler(String input);
+
+  String swizzle(String input, List<StringSwizzler> swizzlers) {
+    var result = input;
+    for (var swizzler in swizzlers) {
+      result = swizzler(result);
+    }
+
+    return result;
+  }
+  ```
+
+  This works fine:
+
+  ```dart
+  main() {
+    var result = swizzle("input", [
+      (s) => s.toUpperCase(),
+      (s) => () => s * 2)
+    ]);
+    print(result); // "INPUTINPUT".
+  }
+  ```
+
+  Later, you realize you'd also like to support swizzlers that are asynchronous
+  (maybe they look up synonyms for words online). You could make your API
+  strictly asynchronous, but then users of simple synchronous swizzlers have to
+  manually wrap the return value in a `Future.value()`. Ideally, your
+  `swizzle()` function would be "polymorphic over asynchrony". It would allow
+  both synchronous and asynchronous swizzlers. Because `await` accepts immediate
+  values, it is easy to implement this dynamically:
+
+  ```dart
+  Future<String> swizzle(String input, List<StringSwizzler> swizzlers) async {
+    var result = input;
+    for (var swizzler in swizzlers) {
+      result = await swizzler(result);
+    }
+
+    return result;
+  }
+
+  main() async {
+    var result = swizzle("input", [
+      (s) => s.toUpperCase(),
+      (s) => new Future.delayed(new Duration(milliseconds: 40), () => s * 2)
+    ]);
+    print(await result);
+  }
+  ```
+
+  What should the declared return type on StringSwizzler be? In the past, you
+  had to use `dynamic` or `Object`, but that doesn't tell the user much. Now,
+  you can do:
+
+  ```dart
+  typedef FutureOr<String> StringSwizzler(String input);
+  ```
+
+  Like the name implies, `FutureOr<String>` is a union type. It can be a
+  `String` or a `Future<String>`, but not anything else. In this case, that's
+  not super useful beyond just stating a more precise type for readers of the
+  code. It does give you a little better error checking in code that uses the
+  result of that.
+
+  `FutureOr<T>` becomes really important in _generic_ methods like
+  `Future.then()`. In those cases, having the type system understand this
+  magical union type helps type inference figure out the type argument of
+  `then()` based on the closure you pass it.
+
+  Previously, strong mode had hard-coded rules for handling `Future.then()`
+  specifically. `FutureOr<T>` exposes that functionality so third-party APIs can
+  take advantage of it too.
+
+### Tool changes
+
+- Dart2Js
+
+  - Remove support for (long-time deprecated) mixin typedefs.
+
+- Pub
+
+  - Avoid using a barback asset server for executables unless they actually use
+    transformers. This makes precompilation substantially faster, produces
+    better error messages when precompilation fails, and allows
+    globally-activated executables to consistently use the
+    `Isolate.resolvePackageUri()` API.
+
+  - On Linux systems, always ignore packages' original file owners and
+    permissions when extracting those packages. This was already the default
+    under most circumstances.
+
+  - Properly close the standard input stream of child processes started using
+    `pub run`.
+
+  - Handle parse errors from the package cache more gracefully. A package whose
+    pubspec can't be parsed will now be ignored by `pub get --offline` and
+    deleted by `pub cache repair`.
+
+  - Make `pub run` run executables in spawned isolates. This lets them handle
+    signals and use standard IO reliably.
+
+  - Fix source-maps produced by dart2js when running in `pub serve`: URL
+    references to assets from packages match the location where `pub serve`
+    serves them (`packages/package_name/` instead of
+    `../packages/package_name/`).
+
+### Infrastructure changes
+
+- The SDK now uses GN rather than gyp to generate its build files, which will
+  now be exclusively ninja flavored. Documentation can be found on our
+  [wiki](https://github.com/dart-lang/sdk/wiki/Building-with-GN). Also see the
+  help message of `tools/gn.py`. This change is in response to the deprecation
+  of gyp. Build file generation with gyp will continue to be available in this
+  release by setting the environment variable `DART_USE_GYP` before running
+  `gclient sync` or `gclient runhooks`, but this will be removed in a future
+  release.
+
+## 1.21.1 - 2017-01-13
+
+Patch release, resolves one issue:
+
+- Dart VM: Snapshots of generic functions fail.
+  [Issue 28072](https://github.com/dart-lang/sdk/issues/28072)
+
+## 1.21.0 - 2016-12-07
+
+### Language
+
+- Support generic method syntax. Type arguments are not available at runtime.
+  For details, check the
+  [informal specification](https://gist.github.com/eernstg/4353d7b4f669745bed3a5423e04a453c).
+- Support access to initializing formals, e.g., the use of `x` to initialize `y`
+  in `class C { var x, y; C(this.x): y = x; }`. Please check the
+  [informal specification](https://gist.github.com/eernstg/cff159be9e34d5ea295d8c24b1a3e594)
+  for details.
+- Don't warn about switch case fallthrough if the case ends in a `rethrow`
+  statement. (SDK issue [27650](https://github.com/dart-lang/sdk/issues/27650))
+- Also don't warn if the entire switch case is wrapped in braces - as long as
+  the block ends with a `break`, `continue`, `rethrow`, `return` or `throw`.
+- Allow `=` as well as `:` as separator for named parameter default values.
+
+  ```dart
+  enableFlags({bool hidden: false}) { … }
+  ```
+
+  can now be replaced by
+
+  ```dart
+  enableFlags({bool hidden = false}) { … }
+  ```
+
+  (SDK issue [27559](https://github.com/dart-lang/sdk/issues/27559))
+
+### Core library changes
+
+- `dart:core`: `Set.difference` now takes a `Set<Object>` as argument. (SDK
+  issue [27573](https://github.com/dart-lang/sdk/issues/27573))
+
+- `dart:developer`
+
+  - Added `Service` class.
+    - Allows inspecting and controlling the VM service protocol HTTP server.
+    - Provides an API to access the ID of an `Isolate`.
+
+### Tool changes
+
+- Dart Dev Compiler
+
+  - Support calls to `loadLibrary()` on deferred libraries. Deferred libraries
+    are still loaded eagerly. (SDK issue
+    [27343](https://github.com/dart-lang/sdk/issues/27343))
+
+## 1.20.1 - 2016-10-13
+
+Patch release, resolves one issue:
+
+- Dartium: Fixes a bug that caused crashes. No issue filed.
+
+### Strong Mode
+
+- It is no longer a warning when casting from dynamic to a composite type (SDK
+  issue [27766](https://github.com/dart-lang/sdk/issues/27766)).
+
+  ```dart
+  main() {
+    dynamic obj = <int>[1, 2, 3];
+    // This is now allowed without a warning.
+    List<int> list = obj;
+  }
+  ```
+
+## 1.20.0 - 2016-10-11
+
+### Dart VM
+
+- We have improved the way that the VM locates the native code library for a
+  native extension (e.g. `dart-ext:` import). We have updated this
+  [article on native extensions](https://dart.dev/server/c-interop-native-extensions)
+  to reflect the VM's improved behavior.
+
+- Linux builds of the VM will now use the `tcmalloc` library for memory
+  allocation. This has the advantages of better debugging and profiling support
+  and faster small allocations, with the cost of slightly larger initial memory
+  footprint, and slightly slower large allocations.
+
+- We have improved the way the VM searches for trusted root certificates for
+  secure socket connections on Linux. First, the VM will look for trusted root
+  certificates in standard locations on the file system
+  (`/etc/pki/tls/certs/ca-bundle.crt` followed by `/etc/ssl/certs`), and only if
+  these do not exist will it fall back on the builtin trusted root certificates.
+  This behavior can be overridden on Linux with the new flags
+  `--root-certs-file` and `--root-certs-cache`. The former is the path to a file
+  containing the trusted root certificates, and the latter is the path to a
+  directory containing root certificate files hashed using `c_rehash`.
+
+- The VM now throws a catchable `Error` when method compilation fails. This
+  allows easier debugging of syntax errors, especially when testing. (SDK issue
+  [23684](https://github.com/dart-lang/sdk/issues/23684))
+
+### Core library changes
+
+- `dart:core`: Remove deprecated `Resource` class. Use the class in
+  `package:resource` instead.
+- `dart:async`
+  - `Future.wait` now catches synchronous errors and returns them in the
+    returned Future. (SDK issue
+    [27249](https://github.com/dart-lang/sdk/issues/27249))
+  - More aggressively returns a `Future` on `Stream.cancel` operations.
+    Discourages to return `null` from `cancel`. (SDK issue
+    [26777](https://github.com/dart-lang/sdk/issues/26777))
+  - Fixes a few bugs where the cancel future wasn't passed through
+    transformations.
+- `dart:io`
+  - Added `WebSocket.addUtf8Text` to allow sending a pre-encoded text message
+    without a round-trip UTF-8 conversion. (SDK issue
+    [27129](https://github.com/dart-lang/sdk/issues/27129))
+
+### Strong Mode
+
+- Breaking change - it is an error if a generic type parameter cannot be
+  inferred (SDK issue [26992](https://github.com/dart-lang/sdk/issues/26992)).
+
+  ```dart
+  class Cup<T> {
+    Cup(T t);
+  }
+  main() {
+    // Error because:
+    // - if we choose Cup<num> it is not assignable to `cOfInt`,
+    // - if we choose Cup<int> then `n` is not assignable to int.
+    num n;
+    C<int> cOfInt = new C(n);
+  }
+  ```
+
+- New feature - use `@checked` to override a method and tighten a parameter type
+  (SDK issue [25578](https://github.com/dart-lang/sdk/issues/25578)).
+
+  ```dart
+  import 'package:meta/meta.dart' show checked;
+  class View {
+    addChild(View v) {}
+  }
+  class MyView extends View {
+    // this override is legal, it will check at runtime if we actually
+    // got a MyView.
+    addChild(@checked MyView v) {}
+  }
+  main() {
+    dynamic mv = new MyView();
+    mv.addChild(new View()); // runtime error
+  }
+  ```
+
+- New feature - use `@virtual` to allow field overrides in strong mode (SDK
+  issue [27384](https://github.com/dart-lang/sdk/issues/27384)).
+
+  ```dart
+  import 'package:meta/meta.dart' show virtual;
+  class Base {
+    @virtual int x;
+  }
+  class Derived extends Base {
+    int x;
+
+    // Expose the hidden storage slot:
+    int get superX => super.x;
+    set superX(int v) { super.x = v; }
+  }
+  ```
+
+- Breaking change - infer list and map literals from the context type as well as
+  their values, consistent with generic methods and instance creation (SDK issue
+  [27151](https://github.com/dart-lang/sdk/issues/27151)).
+
+  ```dart
+  import 'dart:async';
+  main() async {
+    var b = new Future<B>.value(new B());
+    var c = new Future<C>.value(new C());
+    var/*infer List<Future<A>>*/ list = [b, c];
+    var/*infer List<A>*/ result = await Future.wait(list);
+  }
+  class A {}
+  class B extends A {}
+  class C extends A {}
+  ```
+
+### Tool changes
+
+- `dartfmt` - upgraded to v0.2.10
+
+  - Don't crash on annotations before parameters with trailing commas.
+  - Always split enum declarations if they end in a trailing comma.
+  - Add `--set-exit-if-changed` to set the exit code on a change.
+
+- Pub
+  - Pub no longer generates a `packages/` directory by default. Instead, it
+    generates a `.packages` file, called a package spec. To generate a
+    `packages/` directory in addition to the package spec, use the
+    `--packages-dir` flag with `pub get`, `pub upgrade`, and `pub downgrade`.
+    See the
+    [Good-bye symlinks](http://news.dartlang.org/2016/10/good-bye-symlinks.html)
+    article for details.
+
+## 1.19.1 - 2016-09-08
+
+Patch release, resolves one issue:
+
+- Dartdoc: Fixes a bug that prevented generation of docs. (Dartdoc issue
+  [1233](https://github.com/dart-lang/dartdoc/issues/1233))
+
+## 1.19.0 - 2016-08-26
+
+### Language changes
+
+- The language now allows a trailing comma after the last argument of a call and
+  the last parameter of a function declaration. This can make long argument or
+  parameter lists easier to maintain, as commas can be left as-is when
+  reordering lines. For details, see SDK issue
+  [26644](https://github.com/dart-lang/sdk/issues/26644).
+
+### Tool Changes
+
+- `dartfmt` - upgraded to v0.2.9+1
+
+  - Support trailing commas in argument and parameter lists.
+  - Gracefully handle read-only files.
+  - About a dozen other bug fixes.
+
+- Pub
+
+  - Added a `--no-packages-dir` flag to `pub get`, `pub upgrade`, and
+    `pub downgrade`. When this flag is passed, pub will not generate a
+    `packages/` directory, and will remove that directory and any symlinks to it
+    if they exist. Note that this replaces the unsupported
+    `--no-package-symlinks` flag.
+
+  - Added the ability for packages to declare a constraint on the [Flutter][]
+    SDK:
+
+    ```yaml
+    environment:
+      flutter: ^0.1.2
+      sdk: >=1.19.0 <2.0.0
+    ```
+
+    A Flutter constraint will only be satisfiable when pub is running in the
+    context of the `flutter` executable, and when the Flutter SDK version
+    matches the constraint.
+
+  - Added `sdk` as a new package source that fetches packages from a hard-coded
+    SDK. Currently only the `flutter` SDK is supported:
+
+    ```yaml
+    dependencies:
+      flutter_driver:
+        sdk: flutter
+        version: ^0.0.1
+    ```
+
+    A Flutter `sdk` dependency will only be satisfiable when pub is running in
+    the context of the `flutter` executable, and when the Flutter SDK contains a
+    package with the given name whose version matches the constraint.
+
+  - `tar` files on Linux are now created with `0` as the user and group IDs.
+    This fixes a crash when publishing packages while using Active Directory.
+
+  - Fixed a bug where packages from a hosted HTTP URL were considered the same
+    as packages from an otherwise-identical HTTPS URL.
+
+  - Fixed timer formatting for timers that lasted longer than a minute.
+
+  - Eliminate some false negatives when determining whether global executables
+    are on the user's executable path.
+
+- `dart2js`
+  - `dart2dart` (aka `dart2js --output-type=dart`) has been removed (this was
+    deprecated in Dart 1.11).
+
+[flutter]: https://flutter.io/
+
+### Dart VM
+
+- The dependency on BoringSSL has been rolled forward. Going forward, builds of
+  the Dart VM including secure sockets will require a compiler with C++11
+  support. For details, see the
+  [Building wiki page](https://github.com/dart-lang/sdk/wiki/Building).
+
+### Strong Mode
+
+- New feature - an option to disable implicit casts (SDK issue
+  [26583](https://github.com/dart-lang/sdk/issues/26583)), see the
+  [documentation](https://github.com/dart-lang/dev_compiler/blob/master/doc/STATIC_SAFETY.md#disable-implicit-casts)
+  for usage instructions and examples.
+
+- New feature - an option to disable implicit dynamic (SDK issue
+  [25573](https://github.com/dart-lang/sdk/issues/25573)), see the
+  [documentation](https://github.com/dart-lang/dev_compiler/blob/master/doc/STATIC_SAFETY.md#disable-implicit-dynamic)
+  for usage instructions and examples.
+
+- Breaking change - infer generic type arguments from the constructor invocation
+  arguments (SDK issue [25220](https://github.com/dart-lang/sdk/issues/25220)).
+
+  ```dart
+  var map = new Map<String, String>();
+
+  // infer: Map<String, String>
+  var otherMap = new Map.from(map);
+  ```
+
+- Breaking change - infer local function return type (SDK issue
+  [26414](https://github.com/dart-lang/sdk/issues/26414)).
+
+  ```dart
+  void main() {
+    // infer: return type is int
+    f() { return 40; }
+    int y = f() + 2; // type checks
+    print(y);
+  }
+  ```
+
+- Breaking change - allow type promotion from a generic type parameter (SDK
+  issue [26414](https://github.com/dart-lang/sdk/issues/26965)).
+
+  ```dart
+  void fn/*<T>*/(/*=T*/ object) {
+    if (object is String) {
+      // Treat `object` as `String` inside this block.
+      // But it will require a cast to pass it to something that expects `T`.
+      print(object.substring(1));
+    }
+  }
+  ```
+
+- Breaking change - smarter inference for Future.then (SDK issue
+  [25944](https://github.com/dart-lang/sdk/issues/25944)). Previous workarounds
+  that use async/await or `.then/*<Future<SomeType>>*/` should no longer be
+  necessary.
+
+  ```dart
+  // This will now infer correctly.
+  Future<List<int>> t2 = f.then((_) => [3]);
+  // This infers too.
+  Future<int> t2 = f.then((_) => new Future.value(42));
+  ```
+
+- Breaking change - smarter inference for async functions (SDK issue
+  [25322](https://github.com/dart-lang/sdk/issues/25322)).
+
+  ```dart
+  void test() async {
+    List<int> x = await [4]; // was previously inferred
+    List<int> y = await new Future.value([4]); // now inferred too
+  }
+  ```
+
+- Breaking change - sideways casts are no longer allowed (SDK issue
+  [26120](https://github.com/dart-lang/sdk/issues/26120)).
+
+## 1.18.1 - 2016-08-02
+
+Patch release, resolves two issues and improves performance:
+
+- Debugger: Fixes a bug that crashes the VM (SDK issue
+  [26941](https://github.com/dart-lang/sdk/issues/26941))
+
+- VM: Fixes an optimizer bug involving closures, try, and await (SDK issue
+  [26948](https://github.com/dart-lang/sdk/issues/26948))
+
+- Dart2js: Speeds up generated code on Firefox
+  (https://codereview.chromium.org/2180533002)
+
+## 1.18.0 - 2016-07-27
+
+### Core library changes
+
+- `dart:core`
+  - Improved performance when parsing some common URIs.
+  - Fixed bug in `Uri.resolve` (SDK issue
+    [26804](https://github.com/dart-lang/sdk/issues/26804)).
+- `dart:io`
+  - Adds file locking modes `FileLock.BLOCKING_SHARED` and
+    `FileLock.BLOCKING_EXCLUSIVE`.
+
+## 1.17.1 - 2016-06-10
+
+Patch release, resolves two issues:
+
+- VM: Fixes a bug that caused crashes in async functions. (SDK issue
+  [26668](https://github.com/dart-lang/sdk/issues/26668))
+
+- VM: Fixes a bug that caused garbage collection of reachable weak properties.
+  (https://codereview.chromium.org/2041413005)
+
+## 1.17.0 - 2016-06-08
+
+### Core library changes
+
+- `dart:convert`
+
+  - Deprecate `ChunkedConverter` which was erroneously added in 1.16.
+
+- `dart:core`
+
+  - `Uri.replace` supports iterables as values for the query parameters.
+  - `Uri.parseIPv6Address` returns a `Uint8List`.
+
+- `dart:io`
+  - Added `NetworkInterface.listSupported`, which is `true` when
+    `NetworkInterface.list` is supported, and `false` otherwise. Currently,
+    `NetworkInterface.list` is not supported on Android.
+
+### Tool Changes
+
+- Pub
+
+  - TAR files created while publishing a package on Mac OS and Linux now use a
+    more portable format.
+
+  - Errors caused by invalid arguments now print the full usage information for
+    the command.
+
+  - SDK constraints for dependency overrides are no longer considered when
+    determining the total SDK constraint for a lockfile.
+
+  - A bug has been fixed in which a lockfile was considered up-to-date when it
+    actually wasn't.
+
+  - A bug has been fixed in which `pub get --offline` would crash when a
+    prerelease version was selected.
+
+- Dartium and content shell
+  - Debugging Dart code inside iframes improved, was broken.
+
+## 1.16.1 - 2016-05-24
+
+Patch release, resolves one issue:
+
+- VM: Fixes a bug that caused intermittent hangs on Windows. (SDK issue
+  [26400](https://github.com/dart-lang/sdk/issues/26400))
+
+## 1.16.0 - 2016-04-26
+
+### Core library changes
+
+- `dart:convert`
+
+  - Added `BASE64URL` codec and corresponding `Base64Codec.urlSafe` constructor.
+
+  - Introduce `ChunkedConverter` and deprecate chunked methods on `Converter`.
+
+- `dart:html`
+
+  There have been a number of **BREAKING** changes to align APIs with recent
+  changes in Chrome. These include:
+
+  - Chrome's `ShadowRoot` interface no longer has the methods `getElementById`,
+    `getElementsByClassName`, and `getElementsByTagName`, e.g.,
+
+    ```dart
+    elem.shadowRoot.getElementsByClassName('clazz')
+    ```
+
+    should become:
+
+    ```dart
+    elem.shadowRoot.querySelectorAll('.clazz')
+    ```
+
+  - The `clipboardData` property has been removed from `KeyEvent` and `Event`.
+    It has been moved to the new `ClipboardEvent` class, which is now used by
+    `copy`, `cut`, and `paste` events.
+
+  - The `layer` property has been removed from `KeyEvent` and `UIEvent`. It has
+    been moved to `MouseEvent`.
+
+  - The `Point get page` property has been removed from `UIEvent`. It still
+    exists on `MouseEvent` and `Touch`.
+
+  There have also been a number of other additions and removals to `dart:html`,
+  `dart:indexed_db`, `dart:svg`, `dart:web_audio`, and `dart:web_gl` that
+  correspond to changes to Chrome APIs between v39 and v45. Many of the breaking
+  changes represent APIs that would have caused runtime exceptions when compiled
+  to JavaScript and run on recent Chrome releases.
+
+- `dart:io`
+  - Added `SecurityContext.alpnSupported`, which is true if a platform supports
+    ALPN, and false otherwise.
+
+### JavaScript interop
+
+For performance reasons, a potentially **BREAKING** change was added for
+libraries that use JS interop. Any Dart file that uses `@JS` annotations on
+declarations (top-level functions, classes or class members) to interop with
+JavaScript code will require that the file have the annotation `@JS()` on a
+library directive.
+
+```dart
+@JS()
+library my_library;
+```
+
+The analyzer will enforce this by generating the error:
+
+The `@JS()` annotation can only be used if it is also declared on the library
+directive.
+
+If part file uses the `@JS()` annotation, the library that uses the part should
+have the `@JS()` annotation e.g.,
+
+```dart
+// library_1.dart
+@JS()
+library library_1;
+
+import 'package:js/js.dart';
+
+part 'part_1.dart';
+```
+
+```dart
+// part_1.dart
+part of library_1;
+
+@JS("frameworkStabilizers")
+external List<FrameworkStabilizer> get frameworkStabilizers;
+```
+
+If your library already has a JS module e.g.,
+
+```dart
+@JS('array.utils')
+library my_library;
+```
+
+Then your library will work without any additional changes.
+
+### Analyzer
+
+- Static checking of `for in` statements. These will now produce static
+  warnings:
+
+  ```dart
+  // Not Iterable.
+  for (var i in 1234) { ... }
+
+  // String cannot be assigned to int.
+  for (int n in <String>["a", "b"]) { ... }
+  ```
+
+### Tool Changes
+
+- Pub
+
+  - `pub serve` now provides caching headers that should improve the performance
+    of requesting large files multiple times.
+
+  - Both `pub get` and `pub upgrade` now have a `--no-precompile` flag that
+    disables precompilation of executables and transformed dependencies.
+
+  - `pub publish` now resolves symlinks when publishing from a Git repository.
+    This matches the behavior it always had when publishing a package that
+    wasn't in a Git repository.
+
+- Dart Dev Compiler
+
+  - The **experimental** `dartdevc` executable has been added to the SDK.
+
+  - It will help early adopters validate the implementation and provide
+    feedback. `dartdevc` **is not** yet ready for production usage.
+
+  - Read more about the Dart Dev Compiler [here][dartdevc].
+
+[dartdevc]: https://github.com/dart-lang/dev_compiler
+
+## 1.15.0 - 2016-03-09
+
+### Core library changes
+
+- `dart:async`
+
+  - Made `StreamView` class a `const` class.
+
+- `dart:core`
+
+  - Added `Uri.queryParametersAll` to handle multiple query parameters with the
+    same name.
+
+- `dart:io`
+  - Added `SecurityContext.usePrivateKeyBytes`,
+    `SecurityContext.useCertificateChainBytes`,
+    `SecurityContext.setTrustedCertificatesBytes`, and
+    `SecurityContext.setClientAuthoritiesBytes`.
+  - **Breaking** The named `directory` argument of
+    `SecurityContext.setTrustedCertificates` has been removed.
+  - Added support to `SecurityContext` for PKCS12 certificate and key
+    containers.
+  - All calls in `SecurityContext` that accept certificate data now accept an
+    optional named parameter `password`, similar to
+    `SecurityContext.usePrivateKeyBytes`, for use as the password for PKCS12
+    data.
+
+### Tool changes
+
+- Dartium and content shell
+
+  - The Chrome-based tools that ship as part of the Dart SDK - Dartium and
+    content shell - are now based on Chrome version 45 (instead of Chrome 39).
+  - Dart browser libraries (`dart:html`, `dart:svg`, etc) _have not_ been
+    updated.
+    - These are still based on Chrome 39.
+    - These APIs will be updated in a future release.
+  - Note that there are experimental APIs which have changed in the underlying
+    browser, and will not work with the older libraries. For example,
+    `Element.animate`.
+
+- `dartfmt` - upgraded to v0.2.4
+  - Better handling for long collections with comments.
+  - Always put member metadata annotations on their own line.
+  - Indent functions in named argument lists with non-functions.
+  - Force the parameter list to split if a split occurs inside a function-typed
+    parameter.
+  - Don't force a split for before a single named argument if the argument
+    itself splits.
+
+### Service protocol changes
+
+- Fixed a documentation bug where the field `extensionRPCs` in `Isolate` was not
+  marked optional.
+
+### Experimental language features
+
+- Added support for
+  [configuration-specific imports](https://github.com/munificent/dep-interface-libraries/blob/master/Proposal.md).
+  On the VM and `dart2js`, they can be enabled with `--conditional-directives`.
+
+  The analyzer requires additional configuration:
+
+  ```yaml
+  analyzer:
+    language:
+      enableConditionalDirectives: true
+  ```
+
+  Read about [configuring the analyzer] for more details.
+
+[configuring the analyzer]:
+  https://github.com/dart-lang/sdk/tree/master/pkg/analyzer#configuring-the-analyzer
+
+## 1.14.2 - 2016-02-10
+
+Patch release, resolves three issues:
+
+- VM: Fixed a code generation bug on x64. (SDK commit
+  [834b3f02](https://github.com/dart-lang/sdk/commit/834b3f02b6ab740a213fd808e6c6f3269bed80e5))
+
+- `dart:io`: Fixed EOF detection when reading some special device files. (SDK
+  issue [25596](https://github.com/dart-lang/sdk/issues/25596))
+
+- Pub: Fixed an error using hosted dependencies in SDK version 1.14. (Pub issue
+  [1386](https://github.com/dart-lang/pub/issues/1386))
+
+## 1.14.1 - 2016-02-04
+
+Patch release, resolves one issue:
+
+- Debugger: Fixes a VM crash when a debugger attempts to set a break point
+  during isolate initialization. (SDK issue
+  [25618](https://github.com/dart-lang/sdk/issues/25618))
+
+## 1.14.0 - 2016-01-28
+
+### Core library changes
+
+- `dart:async`
+
+  - Added `Future.any` static method.
+  - Added `Stream.fromFutures` constructor.
+
+- `dart:convert`
+
+  - `Base64Decoder.convert` now takes optional `start` and `end` parameters.
+
+- `dart:core`
+
+  - Added `current` getter to `StackTrace` class.
+  - `Uri` class added support for data URIs
+    - Added two new constructors: `dataFromBytes` and `dataFromString`.
+    - Added a `data` getter for `data:` URIs with a new `UriData` class for the
+      return type.
+  - Added `growable` parameter to `List.filled` constructor.
+  - Added microsecond support to `DateTime`: `DateTime.microsecond`,
+    `DateTime.microsecondsSinceEpoch`, and
+    `new DateTime.fromMicrosecondsSinceEpoch`.
+
+- `dart:math`
+
+  - `Random` added a `secure` constructor returning a cryptographically secure
+    random generator which reads from the entropy source provided by the
+    embedder for every generated random value.
+
+- `dart:io`
+
+  - `Platform` added a static `isIOS` getter and `Platform.operatingSystem` may
+    now return `ios`.
+  - `Platform` added a static `packageConfig` getter.
+  - Added support for WebSocket compression as standardized in RFC 7692.
+  - Compression is enabled by default for all WebSocket connections.
+    - The optionally named parameter `compression` on the methods
+      `WebSocket.connect`, `WebSocket.fromUpgradedSocket`, and
+      `WebSocketTransformer.upgrade` and the `WebSocketTransformer` constructor
+      can be used to modify or disable compression using the new
+      `CompressionOptions` class.
+
+- `dart:isolate`
+  - Added **_experimental_** support for [Package Resolution Configuration].
+    - Added `packageConfig` and `packageRoot` instance getters to `Isolate`.
+    - Added a `resolvePackageUri` method to `Isolate`.
+    - Added named arguments `packageConfig` and `automaticPackageResolution` to
+      the `Isolate.spawnUri` constructor.
+
+[package resolution configuration]:
+  https://github.com/dart-lang/dart_enhancement_proposals/blob/master/Accepted/0005%20-%20Package%20Specification/DEP-pkgspec.md
+
+### Tool changes
+
+- `dartfmt`
+
+  - Better line splitting in a variety of cases.
+
+  - Other optimizations and bug fixes.
+
+- Pub
+
+  - **Breaking:** Pub now eagerly emits an error when a pubspec's "name" field
+    is not a valid Dart identifier. Since packages with non-identifier names
+    were never allowed to be published, and some of them already caused crashes
+    when being written to a `.packages` file, this is unlikely to break many
+    people in practice.
+
+  - **Breaking:** Support for `barback` versions prior to 0.15.0 (released July
+
+    1.  has been dropped. Pub will no longer install these older barback
+        versions.
+
+  - `pub serve` now GZIPs the assets it serves to make load times more similar
+    to real-world use-cases.
+
+  - `pub deps` now supports a `--no-dev` flag, which causes it to emit the
+    dependency tree as it would be if no `dev_dependencies` were in use. This
+    makes it easier to see your package's dependency footprint as your users
+    will experience it.
+
+  - `pub global run` now detects when a global executable's SDK constraint is no
+    longer met and errors out, rather than trying to run the executable anyway.
+
+  - Pub commands that check whether the lockfile is up-to-date (`pub run`,
+    `pub deps`, `pub serve`, and `pub build`) now do additional verification.
+    They ensure that any path dependencies' pubspecs haven't been changed, and
+    they ensure that the current SDK version is compatible with all
+    dependencies.
+
+  - Fixed a crashing bug when using `pub global run` on a global script that
+    didn't exist.
+
+  - Fixed a crashing bug when a pubspec contains a dependency without a source
+    declared.
+
+## 1.13.2 - 2016-01-06
+
+Patch release, resolves one issue:
+
+- dart2js: Stack traces are not captured correctly (SDK issue [25235]
+  (https://github.com/dart-lang/sdk/issues/25235))
+
+## 1.13.1 - 2015-12-17
+
+Patch release, resolves three issues:
+
+- VM type propagation fix: Resolves a potential crash in the Dart VM (SDK commit
+  [dff13be]
+  (https://github.com/dart-lang/sdk/commit/dff13bef8de104d33b04820136da2d80f3c835d7))
+
+- dart2js crash fix: Resolves a crash in pkg/js and dart2js (SDK issue [24974]
+  (https://github.com/dart-lang/sdk/issues/24974))
+
+- Pub get crash on ARM: Fixes a crash triggered when running 'pub get' on ARM
+  processors such as those on a Raspberry Pi (SDK issue [24855]
+  (https://github.com/dart-lang/sdk/issues/24855))
+
+## 1.13.0 - 2015-11-18
+
+### Core library changes
+
+- `dart:async`
+
+  - `StreamController` added getters for `onListen`, `onPause`, and `onResume`
+    with the corresponding new `typedef void ControllerCallback()`.
+  - `StreamController` added a getter for `onCancel` with the corresponding new
+    `typedef ControllerCancelCallback()`;
+  - `StreamTransformer` instances created with `fromHandlers` with no
+    `handleError` callback now forward stack traces along with errors to the
+    resulting streams.
+
+- `dart:convert`
+
+  - Added support for Base-64 encoding and decoding.
+    - Added new classes `Base64Codec`, `Base64Encoder`, and `Base64Decoder`.
+    - Added new top-level `const Base64Codec BASE64`.
+
+- `dart:core`
+
+  - `Uri` added `removeFragment` method.
+  - `String.allMatches` (implementing `Pattern.allMatches`) is now lazy, as all
+    `allMatches` implementations are intended to be.
+  - `Resource` is deprecated, and will be removed in a future release.
+
+- `dart:developer`
+
+  - Added `Timeline` class for interacting with Observatory's timeline feature.
+  - Added `ServiceExtensionHandler`, `ServiceExtensionResponse`, and
+    `registerExtension` which enable developers to provide their own VM service
+    protocol extensions.
+
+- `dart:html`, `dart:indexed_db`, `dart:svg`, `dart:web_audio`, `dart:web_gl`,
+  `dart:web_sql`
+
+  - The return type of some APIs changed from `double` to `num`. Dartium is now
+    using JS interop for most operations. JS does not distinguish between
+    numeric types, and will return a number as an int if it fits in an int. This
+    will mostly cause an error if you assign to something typed `double` in
+    checked mode. You may need to insert a `toDouble()` call or accept `num`.
+    Examples of APIs that are affected include `Element.getBoundingClientRect`
+    and `TextMetrics.width`.
+
+- `dart:io`
+
+  - **Breaking:** Secure networking has changed, replacing the NSS library with
+    the BoringSSL library. `SecureSocket`, `SecureServerSocket`,
+    `RawSecureSocket`,`RawSecureServerSocket`, `HttpClient`, and `HttpServer`
+    now all use a `SecurityContext` object which contains the certificates and
+    keys used for secure TLS (SSL) networking.
+
+    This is a breaking change for server applications and for some client
+    applications. Certificates and keys are loaded into the `SecurityContext`
+    from PEM files, instead of from an NSS certificate database. Information
+    about how to change applications that use secure networking is at
+    https://www.dartlang.org/server/tls-ssl.html
+
+  - `HttpClient` no longer sends URI fragments in the request. This is not
+    allowed by the HTTP protocol. The `HttpServer` still gracefully receives
+    fragments, but discards them before delivering the request.
+  - To allow connections to be accepted on the same port across different
+    isolates, set the `shared` argument to `true` when creating server socket
+    and `HttpServer` instances.
+    - The deprecated `ServerSocketReference` and `RawServerSocketReference`
+      classes have been removed.
+    - The corresponding `reference` properties on `ServerSocket` and
+      `RawServerSocket` have been removed.
+
+- `dart:isolate`
+  - `spawnUri` added an `environment` named argument.
+
+### Tool changes
+
+- `dart2js` and Dartium now support improved JavaScript Interoperability via the
+  [js package](https://pub.dev/packages/js).
+
+- `docgen` and `dartdocgen` no longer ship in the SDK. The `docgen` sources have
+  been removed from the repository.
+
+- This is the last release to ship the VM's "legacy debug protocol". We intend
+  to remove the legacy debug protocol in Dart VM 1.14.
+
+- The VM's Service Protocol has been updated to version 3.0 to take care of a
+  number of issues uncovered by the first few non-observatory clients. This is a
+  potentially breaking change for clients.
+
+- Dartium has been substantially changed. Rather than using C++ calls into
+  Chromium internals for DOM operations it now uses JS interop. The DOM objects
+  in `dart:html` and related libraries now wrap a JavaScript object and delegate
+  operations to it. This should be mostly transparent to users. However,
+  performance and memory characteristics may be different from previous
+  versions. There may be some changes in which DOM objects are wrapped as Dart
+  objects. For example, if you get a reference to a Window object, even through
+  JS interop, you will always see it as a Dart Window, even when used
+  cross-frame. We expect the change to using JS interop will make it much
+  simpler to update to new Chrome versions.
+
+## 1.12.2 - 2015-10-21
+
+### Core library changes
+
+- `dart:io`
+
+  - A memory leak in creation of Process objects is fixed.
+
+## 1.12.1 - 2015-09-08
+
+### Tool changes
+
+- Pub
+
+  - Pub will now respect `.gitignore` when validating a package before it's
+    published. For example, if a `LICENSE` file exists but is ignored, that is
+    now an error.
+
+  - If the package is in a subdirectory of a Git repository and the entire
+    subdirectory is ignored with `.gitignore`, pub will act as though nothing
+    was ignored instead of uploading an empty package.
+
+  - The heuristics for determining when `pub get` needs to be run before various
+    commands have been improved. There should no longer be false positives when
+    non-dependency sections of the pubspec have been modified.
+
+## 1.12.0 - 2015-08-31
+
+### Language changes
+
+- Null-aware operators
+  - `??`: if null operator. `expr1 ?? expr2` evaluates to `expr1` if not `null`,
+    otherwise `expr2`.
+  - `??=`: null-aware assignment. `v ??= expr` causes `v` to be assigned `expr`
+    only if `v` is `null`.
+  - `x?.p`: null-aware access. `x?.p` evaluates to `x.p` if `x` is not `null`,
+    otherwise evaluates to `null`.
+  - `x?.m()`: null-aware method invocation. `x?.m()` invokes `m` only if `x` is
+    not `null`.
+
+### Core library changes
+
+- `dart:async`
+
+  - `StreamController` added setters for the `onListen`, `onPause`, `onResume`
+    and `onCancel` callbacks.
+
+- `dart:convert`
+
+  - `LineSplitter` added a `split` static method returning an `Iterable`.
+
+- `dart:core`
+
+  - `Uri` class now perform path normalization when a URI is created. This
+    removes most `..` and `.` sequences from the URI path. Purely relative paths
+    (no scheme or authority) are allowed to retain some leading "dot" segments.
+    Also added `hasAbsolutePath`, `hasEmptyPath`, and `hasScheme` properties.
+
+- `dart:developer`
+
+  - New `log` function to transmit logging events to Observatory.
+
+- `dart:html`
+
+  - `NodeTreeSanitizer` added the `const trusted` field. It can be used instead
+    of defining a `NullTreeSanitizer` class when calling `setInnerHtml` or other
+    methods that create DOM from text. It is also more efficient, skipping the
+    creation of a `DocumentFragment`.
+
+- `dart:io`
+
+  - Added two new file modes, `WRITE_ONLY` and `WRITE_ONLY_APPEND` for opening a
+    file write only.
+    [eaeecf2](https://github.com/dart-lang/sdk/commit/eaeecf2ed13ba6c7fbfd653c3c592974a7120960)
+  - Change stdout/stderr to binary mode on Windows.
+    [4205b29](https://github.com/dart-lang/sdk/commit/4205b2997e01f2cea8e2f44c6f46ed6259ab7277)
+
+- `dart:isolate`
+
+  - Added `onError`, `onExit` and `errorsAreFatal` parameters to
+    `Isolate.spawnUri`.
+
+- `dart:mirrors`
+  - `InstanceMirror.delegate` moved up to `ObjectMirror`.
+  - Fix InstanceMirror.getField optimization when the selector is an operator.
+  - Fix reflective NoSuchMethodErrors to match their non-reflective counterparts
+    when due to argument mismatches. (VM only)
+
+### Tool changes
+
+- Documentation tools
+
+  - `dartdoc` is now the default tool to generate static HTML for API docs.
+    [Learn more](https://pub.dev/packages/dartdoc).
+
+  - `docgen` and `dartdocgen` have been deprecated. Currently plan is to remove
+    them in 1.13.
+
+- Formatter (`dartfmt`)
+
+  - Over 50 bugs fixed.
+
+  - Optimized line splitter is much faster and produces better output on complex
+    code.
+
+- Observatory
+
+  - Allocation profiling.
+
+  - New feature to display output from logging.
+
+  - Heap snapshot analysis works for 64-bit VMs.
+
+  - Improved ability to inspect typed data, regex and compiled code.
+
+  - Ability to break on all or uncaught exceptions from Observatory's debugger.
+
+  - Ability to set closure-specific breakpoints.
+
+  - 'anext' - step past await/yield.
+
+  - Preserve when a variable has been expanded/unexpanded in the debugger.
+
+  - Keep focus on debugger input box whenever possible.
+
+  - Echo stdout/stderr in the Observatory debugger. Standalone-only so far.
+
+  - Minor fixes to service protocol documentation.
+
+- Pub
+
+  - **Breaking:** various commands that previously ran `pub get` implicitly no
+    longer do so. Instead, they merely check to make sure the ".packages" file
+    is newer than the pubspec and the lock file, and fail if it's not.
+
+  - Added support for `--verbosity=error` and `--verbosity=warning`.
+
+  - `pub serve` now collapses multiple GET requests into a single line of
+    output. For full output, use `--verbose`.
+
+  - `pub deps` has improved formatting for circular dependencies on the
+    entrypoint package.
+
+  - `pub run` and `pub global run`
+
+    - **Breaking:** to match the behavior of the Dart VM, executables no longer
+      run in checked mode by default. A `--checked` flag has been added to run
+      them in checked mode manually.
+
+    - Faster start time for executables that don't import transformed code.
+
+    - Binstubs for globally-activated executables are now written in the system
+      encoding, rather than always in `UTF-8`. To update existing executables,
+      run `pub cache repair`.
+
+  - `pub get` and `pub upgrade`
+
+    - Pub will now generate a ".packages" file in addition to the "packages"
+      directory when running `pub get` or similar operations, per the [package
+      spec proposal][]. Pub now has a `--no-package-symlinks` flag that will
+      stop "packages" directories from being generated at all.
+
+    - An issue where HTTP requests were sometimes made even though `--offline`
+      was passed has been fixed.
+
+    - A bug with `--offline` that caused an unhelpful error message has been
+      fixed.
+
+    - Pub will no longer time out when a package takes a long time to download.
+
+  - `pub publish`
+
+    - Pub will emit a non-zero exit code when it finds a violation while
+      publishing.
+
+    - `.gitignore` files will be respected even if the package isn't at the top
+      level of the Git repository.
+
+  - Barback integration
+
+    - A crashing bug involving transformers that only apply to non-public code
+      has been fixed.
+
+    - A deadlock caused by declaring transformer followed by a lazy transformer
+      (such as the built-in `$dart2js` transformer) has been fixed.
+
+    - A stack overflow caused by a transformer being run multiple times on the
+      package that defines it has been fixed.
+
+    - A transformer that tries to read a nonexistent asset in another package
+      will now be re-run if that asset is later created.
+
+[package spec proposal]: https://github.com/lrhn/dep-pkgspec
+
+### VM Service Protocol Changes
+
+- **BREAKING** The service protocol now sends JSON-RPC 2.0-compatible
+  server-to-client events. To reflect this, the service protocol version is now
+  2.0.
+
+- The service protocol now includes a `"jsonrpc"` property in its responses, as
+  opposed to `"json-rpc"`.
+
+- The service protocol now properly handles requests with non-string ids.
+  Numeric ids are no longer converted to strings, and null ids now don't produce
+  a response.
+
+- Some RPCs that didn't include a `"jsonrpc"` property in their responses now
+  include one.
+
+## 1.11.2 - 2015-08-03
+
+### Core library changes
+
+- Fix a bug where `WebSocket.close()` would crash if called after
+  `WebSocket.cancel()`.
+
+## 1.11.1 - 2015-07-02
+
+### Tool changes
+
+- Pub will always load Dart SDK assets from the SDK whose `pub` executable was
+  run, even if a `DART_SDK` environment variable is set.
+
+## 1.11.0 - 2015-06-25
+
+### Core library changes
+
+- `dart:core`
+
+  - `Iterable` added an `empty` constructor.
+    [dcf0286](https://github.com/dart-lang/sdk/commit/dcf0286f5385187a68ce9e66318d3bf19abf454b)
+  - `Iterable` can now be extended directly. An alternative to extending
+    `IterableBase` from `dart:collection`.
+  - `List` added an `unmodifiable` constructor.
+    [r45334](https://code.google.com/p/dart/source/detail?r=45334)
+  - `Map` added an `unmodifiable` constructor.
+    [r45733](https://code.google.com/p/dart/source/detail?r=45733)
+  - `int` added a `gcd` method.
+    [a192ef4](https://github.com/dart-lang/sdk/commit/a192ef4acb95fad1aad1887f59eed071eb5e8201)
+  - `int` added a `modInverse` method.
+    [f6f338c](https://github.com/dart-lang/sdk/commit/f6f338ce67eb8801b350417baacf6d3681b26002)
+  - `StackTrace` added a `fromString` constructor.
+    [68dd6f6](https://github.com/dart-lang/sdk/commit/68dd6f6338e63d0465041d662e778369c02c2ce6)
+  - `Uri` added a `directory` constructor.
+    [d8dbb4a](https://github.com/dart-lang/sdk/commit/d8dbb4a60f5e8a7f874c2a4fbf59eaf1a39f4776)
+  - List iterators may not throw `ConcurrentModificationError` as eagerly in
+    release mode. In checked mode, the modification check is still as eager as
+    possible. [r45198](https://github.com/dart-lang/sdk/commit/5a79c03)
+
+- `dart:developer` - **NEW**
+
+  - Replaces the deprecated `dart:profiler` library.
+  - Adds new functions `debugger` and `inspect`.
+    [6e42aec](https://github.com/dart-lang/sdk/blob/6e42aec4f64cf356dde7bad9426e07e0ea5b58d5/sdk/lib/developer/developer.dart)
+
+- `dart:io`
+
+  - `FileSystemEntity` added a `uri` property.
+    [8cf32dc](https://github.com/dart-lang/sdk/commit/8cf32dc1a1664b516e57f804524e46e55fae88b2)
+  - `Platform` added a `static resolvedExecutable` property.
+    [c05c8c6](https://github.com/dart-lang/sdk/commit/c05c8c66069db91cc2fd48691dfc406c818d411d)
+
+- `dart:html`
+
+  - `Element` methods, `appendHtml` and `insertAdjacentHtml` now take
+    `nodeValidator` and `treeSanitizer` parameters, and the inputs are
+    consistently sanitized.
+    [r45818 announcement](https://groups.google.com/a/dartlang.org/forum/#!topic/announce/GVO7EAcPi6A)
+
+- `dart:isolate`
+
+  - **BREAKING** The positional `priority` parameter of `Isolate.ping` and
+    `Isolate.kill` is now a named parameter named `priority`.
+  - **BREAKING** Removed the `Isolate.AS_EVENT` priority.
+  - `Isolate` methods `ping` and `addOnExitListener` now have a named parameter
+    `response`. [r45092](https://github.com/dart-lang/sdk/commit/1b208bd)
+  - `Isolate.spawnUri` added a named argument `checked`.
+  - Remove the experimental state of the API.
+
+- `dart:profiler` - **DEPRECATED**
+  - This library will be removed in 1.12. Use `dart:developer` instead.
+
+### Tool changes
+
+- This is the first release that does not include the Eclipse-based **Dart
+  Editor**. See [dart.dev/tools](https://dart.dev/tools#ides-and-editors) for
+  alternatives.
+- This is the last release that ships the (unsupported) dart2dart (aka
+  `dart2js --output-type=dart`) utility as part of dart2js
+
+## 1.10.0 - 2015-04-29
+
+### Core library changes
+
+- `dart:convert`
+
+  - **POTENTIALLY BREAKING** Fix behavior of `HtmlEscape`. It no longer escapes
+    no-break space (U+00A0) anywhere or forward slash (`/`, `U+002F`) in element
+    context. Slash is still escaped using `HtmlEscapeMode.UNKNOWN`.
+    [r45003](https://github.com/dart-lang/sdk/commit/8b8223d),
+    [r45153](https://github.com/dart-lang/sdk/commit/8a5d049),
+    [r45189](https://github.com/dart-lang/sdk/commit/3c39ad2)
+
+- `dart:core`
+
+  - `Uri.parse` added `start` and `end` positional arguments.
+
+- `dart:html`
+
+  - **POTENTIALLY BREAKING** `CssClassSet` method arguments must now be
+    'tokens', i.e. non-empty strings with no white-space characters. The
+    implementation was incorrect for class names containing spaces. The fix is
+    to forbid spaces and provide a faster implementation.
+    [Announcement](https://groups.google.com/a/dartlang.org/d/msg/announce/jmUI2XJHfC8/UZUCvJH3p2oJ)
+
+- `dart:io`
+
+  - `ProcessResult` now exposes a constructor.
+  - `import` and `Isolate.spawnUri` now supports the
+    [Data URI scheme](http://en.wikipedia.org/wiki/Data_URI_scheme) on the VM.
+
+### Tool Changes
+
+#### pub
+
+- Running `pub run foo` within a package now runs the `foo` executable defined
+  by the `foo` package. The previous behavior ran `bin/foo`. This makes it easy
+  to run binaries in dependencies, for instance `pub run test`.
+
+- On Mac and Linux, signals sent to `pub run` and forwarded to the child
+  command.
+
+## 1.9.3 - 2015-04-14
+
+This is a bug fix release which merges a number of commits from `bleeding_edge`.
+
+- dart2js: Addresses as issue with minified JavaScript output with CSP enabled -
+  [r44453](https://code.google.com/p/dart/source/detail?r=44453)
+
+- Editor: Fixes accidental updating of files in the pub cache during rename
+  refactoring - [r44677](https://code.google.com/p/dart/source/detail?r=44677)
+
+- Editor: Fix for
+  [issue 23032](https://code.google.com/p/dart/issues/detail?id=23032) regarding
+  skipped breakpoints on Windows -
+  [r44824](https://code.google.com/p/dart/source/detail?r=44824)
+
+- dart:mirrors: Fix `MethodMirror.source` when the method is on the first line
+  in a script - [r44957](https://code.google.com/p/dart/source/detail?r=44957),
+  [r44976](https://code.google.com/p/dart/source/detail?r=44976)
+
+- pub: Fix for
+  [issue 23084](https://code.google.com/p/dart/issues/detail?id=23084): Pub can
+  fail to load transformers necessary for local development -
+  [r44876](https://code.google.com/p/dart/source/detail?r=44876)
+
+## 1.9.1 - 2015-03-25
+
+### Language changes
+
+- Support for `async`, `await`, `sync*`, `async*`, `yield`, `yield*`, and
+  `await for`. See the [the language tour][async] for more details.
+
+- Enum support is fully enabled. See [the language tour][enum] for more details.
+
+[async]: https://dart.dev/guides/language/language-tour#asynchrony
+[enum]: https://dart.dev/guides/language/language-tour#enums
+
+### Tool changes
+
+- The formatter is much more comprehensive and generates much more readable
+  code. See [its tool page][dartfmt] for more details.
+
+- The analysis server is integrated into the IntelliJ plugin and the Dart
+  editor. This allows analysis to run out-of-process, so that interaction
+  remains smooth even for large projects.
+
+- Analysis supports more and better hints, including unused variables and unused
+  private members.
+
+[dartfmt]: https://dart.dev/tools/dart-format
+
+### Core library changes
+
+#### Highlights
+
+- There's a new model for shared server sockets with no need for a `Socket`
+  reference.
+
+- A new, much faster [regular expression engine][regexp].
+
+- The Isolate API now works across the VM and `dart2js`.
+
+[regexp]: http://news.dartlang.org/2015/02/irregexp-dart-vms-new-regexp.html
+
+#### Details
+
+For more information on any of these changes, see the corresponding
+documentation on the [Dart API site](http://api.dart.dev).
+
+- `dart:async`:
+
+  - `Future.wait` added a new named argument, `cleanUp`, which is a callback
+    that releases resources allocated by a successful `Future`.
+
+  - The `SynchronousStreamController` class was added as an explicit name for
+    the type returned when the `sync` argument is passed to
+    `new StreamController`.
+
+- `dart:collection`: The `new SplayTreeSet.from(Iterable)` constructor was
+  added.
+
+- `dart:convert`: `Utf8Encoder.convert` and `Utf8Decoder.convert` added optional
+  `start` and `end` arguments.
+
+- `dart:core`:
+
+  - `RangeError` added new static helper functions: `checkNotNegative`,
+    `checkValidIndex`, `checkValidRange`, and `checkValueInInterval`.
+
+  - `int` added the `modPow` function.
+
+  - `String` added the `replaceFirstMapped` and `replaceRange` functions.
+
+- `dart:io`:
+
+  - Support for locking files to prevent concurrent modification was added. This
+    includes the `File.lock`, `File.lockSync`, `File.unlock`, and
+    `File.unlockSync` functions as well as the `FileLock` class.
+
+  - Support for starting detached processes by passing the named `mode` argument
+    (a `ProcessStartMode`) to `Process.start`. A process can be fully attached,
+    fully detached, or detached except for its standard IO streams.
+
+  - `HttpServer.bind` and `HttpServer.bindSecure` added the `v6Only` named
+    argument. If this is true, only IPv6 connections will be accepted.
+
+  - `HttpServer.bind`, `HttpServer.bindSecure`, `ServerSocket.bind`,
+    `RawServerSocket.bind`, `SecureServerSocket.bind` and
+    `RawSecureServerSocket.bind` added the `shared` named argument. If this is
+    true, multiple servers or sockets in the same Dart process may bind to the
+    same address, and incoming requests will automatically be distributed
+    between them.
+
+  - **Deprecation:** the experimental `ServerSocketReference` and
+    `RawServerSocketReference` classes, as well as getters that returned them,
+    are marked as deprecated. The `shared` named argument should be used
+    instead. These will be removed in Dart 1.10.
+
+  - `Socket.connect` and `RawSocket.connect` added the `sourceAddress` named
+    argument, which specifies the local address to bind when making a
+    connection.
+
+  - The static `Process.killPid` method was added to kill a process with a given
+    PID.
+
+  - `Stdout` added the `nonBlocking` instance property, which returns a
+    non-blocking `IOSink` that writes to standard output.
+
+- `dart:isolate`:
+
+  - The static getter `Isolate.current` was added.
+
+  - The `Isolate` methods `addOnExitListener`, `removeOnExitListener`,
+    `setErrorsFatal`, `addOnErrorListener`, and `removeOnErrorListener` now work
+    on the VM.
+
+  - Isolates spawned via `Isolate.spawn` now allow most objects, including
+    top-level and static functions, to be sent between them.
+
+## 1.8.5 - 2015-01-21
+
+- Code generation for SIMD on ARM and ARM64 is fixed.
+
+- A possible crash on MIPS with newer GCC toolchains has been prevented.
+
+- A segfault when using `rethrow` was fixed ([issue 21795][]).
+
+[issue 21795]: https://code.google.com/p/dart/issues/detail?id=21795
+
+## 1.8.3 - 2014-12-10
+
+- Breakpoints can be set in the Editor using file suffixes ([issue 21280][]).
+
+- IPv6 addresses are properly handled by `HttpClient` in `dart:io`, fixing a
+  crash in pub ([issue 21698][]).
+
+- Issues with the experimental `async`/`await` syntax have been fixed.
+
+- Issues with a set of number operations in the VM have been fixed.
+
+- `ListBase` in `dart:collection` always returns an `Iterable` with the correct
+  type argument.
+
+[issue 21280]: https://code.google.com/p/dart/issues/detail?id=21280
+[issue 21698]: https://code.google.com/p/dart/issues/detail?id=21698
+
+## 1.8.0 - 2014-11-28
+
+- `dart:collection`: `SplayTree` added the `toSet` function.
+
+- `dart:convert`: The `JsonUtf8Encoder` class was added.
+
+- `dart:core`:
+
+  - The `IndexError` class was added for errors caused by an index being outside
+    its expected range.
+
+  - The `new RangeError.index` constructor was added. It forwards to
+    `new IndexError`.
+
+  - `RangeError` added three new properties. `invalidProperty` is the value that
+    caused the error, and `start` and `end` are the minimum and maximum values
+    that the value is allowed to assume.
+
+  - `new RangeError.value` and `new RangeError.range` added an optional
+    `message` argument.
+
+  - The `new String.fromCharCodes` constructor added optional `start` and `end`
+    arguments.
+
+- `dart:io`:
+
+  - Support was added for the [Application-Layer Protocol Negotiation][alpn]
+    extension to the TLS protocol for both the client and server.
+
+  - `SecureSocket.connect`, `SecureServerSocket.bind`,
+    `RawSecureSocket.connect`, `RawSecureSocket.secure`,
+    `RawSecureSocket.secureServer`, and `RawSecureServerSocket.bind` added a
+    `supportedProtocols` named argument for protocol negotiation.
+
+  - `RawSecureServerSocket` added a `supportedProtocols` field.
+
+  - `RawSecureSocket` and `SecureSocket` added a `selectedProtocol` field which
+    contains the protocol selected during protocol negotiation.
+
+[alpn]: https://tools.ietf.org/html/rfc7301
+
+## 1.7.0 - 2014-10-15
+
+### Tool changes
+
+- `pub` now generates binstubs for packages that are globally activated so that
+  they can be put on the user's `PATH` and used as normal executables. See the
+  [`pub global activate` documentation][pub global activate].
+
+- When using `dart2js`, deferred loading now works with multiple Dart apps on
+  the same page.
+
+[pub global activate]:
+  https://dart.dev/tools/pub/cmd/pub-global#running-a-script-from-your-path
+
+### Core library changes
+
+- `dart:async`: `Zone`, `ZoneDelegate`, and `ZoneSpecification` added the
+  `errorCallback` function, which allows errors that have been programmatically
+  added to a `Future` or `Stream` to be intercepted.
+
+- `dart:io`:
+
+  - **Breaking change:** `HttpClient.close` must be called for all clients or
+    they will keep the Dart process alive until they time out. This fixes the
+    handling of persistent connections. Previously, the client would shut down
+    immediately after a request.
+
+  - **Breaking change:** `HttpServer` no longer compresses all traffic by
+    default. The new `autoCompress` property can be set to `true` to re-enable
+    compression.
+
+- `dart:isolate`: `Isolate.spawnUri` added the optional `packageRoot` argument,
+  which controls how it resolves `package:` URIs.
diff --git a/test_files/source/Dart web.md b/test_files/source/Dart web.md
new file mode 100644
index 0000000..8606ee7
--- /dev/null
+++ b/test_files/source/Dart web.md	
@@ -0,0 +1,76 @@
+[![Dart CI](https://github.com/dart-lang/web/actions/workflows/build.yml/badge.svg)](https://github.com/dart-lang/web/actions/workflows/build.yml)
+[![pub package](https://img.shields.io/pub/v/web.svg)](https://pub.dev/packages/web)
+[![package publisher](https://img.shields.io/pub/publisher/web.svg)](https://pub.dev/packages/web/publisher)
+
+Lightweight browser API bindings built around
+[JS interop](https://dart.dev/interop/js-interop).
+
+## What's this?
+
+This package exposes browser APIs. It's generated from the Web IDL definitions
+and uses recent Dart language features for zero-overhead bindings.
+
+This package is intended to replace
+[`dart:html`](https://api.dart.dev/stable/dart-html/dart-html-library.html) and
+similar Dart SDK libraries. It will support access to browser APIs from Dart
+code compiled to either JavaScript or WebAssembly.
+
+## Usage
+
+```dart
+import 'package:web/web.dart';
+
+void main() {
+  final div = document.querySelector('div')!;
+  div.text = 'Text set at ${DateTime.now()}';
+}
+```
+
+## Migrating to package:web
+
+`package:web` is replacing `dart:html` and other web libraries as Dart's 
+long-term web interop solution. To learn how to migrate from `dart:html`
+APIs to `package:web`, see our
+[migration guide](http://dart.dev/go/package-web).
+
+## Generation conventions
+
+The generator scripts use a number of conventions to consistently handle Web IDL
+definitions:
+
+### Interfaces
+
+- Interfaces are emitted as extension types that wrap and implement `JSObject`.
+- Interface inheritance is maintained using `implements` between extension
+  types.
+- Members of partial interfaces, partial mixins, and mixins are added to the
+  interfaces that include them, and therefore do not have separate declarations.
+
+### Types
+
+- Generic types include the generic in the case of `JSArray` and `JSPromise`.
+- Enums are typedef'd to `String`.
+- Callbacks and callback interfaces are typedef'd to `JSFunction`.
+- In general, we prefer the Dart primitive over the JS type equivalent wherever
+  possible. For example, APIs use `String` instead of `JSString`.
+- If a type appears in a generic position and it was typedef'd to a Dart
+  primitive type, it is replaced with the JS type equivalent to respect the type
+  bound of `JSAny?`.
+- Union types are computed by picking the least upper bound of the types in the
+  JS type hierarchy, where every interface is equivalent to `JSObject`.
+
+### Compatibility
+
+- The generator uses the
+  [MDN compatibility data](https://github.com/mdn/browser-compat-data) to
+  determine what members and interfaces to emit. Currently, we only emit code
+  that is standards track and supported on Chrome, Firefox, and Safari to reduce
+  the number of breaking changes. This is currently WIP and some members may be
+  added or removed.
+
+## Generation and updating the package
+
+Most of the APIs in this package are generated from public assets. See
+[tool/README.md](https://github.com/dart-lang/web/tree/main/tool) for
+information on the spec and IDL versions the package was generated from, and for
+the process for updating the package.
diff --git a/test_files/source/Especificacao.pdf b/test_files/source/Especificacao.pdf
new file mode 100644
index 0000000..1530e3d
Binary files /dev/null and b/test_files/source/Especificacao.pdf differ
diff --git a/test_files/source/Mudancas quebradas.md b/test_files/source/Mudancas quebradas.md
new file mode 100644
index 0000000..67b0d8c
--- /dev/null
+++ b/test_files/source/Mudancas quebradas.md	
@@ -0,0 +1,1086 @@
+---
+title: Breaking changes and deprecations
+description: A list of breaking changes by release in Dart.
+---
+
+This page lists all language and library breaking changes and deprecations in Dart,
+organized by release and area, to help Dart users understand and manage their
+impact. Complete release notes are available in the [Dart SDK changelog][changelog].
+The [breaking change policy][] document describes the policy and process
+around breaking changes and deprecations in Dart. 
+
+**This page includes the following types of breaking changes**:
+
+* **Unversioned**: The Dart SDK does not maintain backward compatibility, and
+  code may break as soon as you [upgrade your sdk version][sdk] if it relies on
+  the previous behavior.
+  
+  _These are the majority of changes and are not specially marked in this list._
+* **Language versioned**: The Dart SDK maintains backward compatibility for
+  existing code, and the behavior change only takes effect (potentially breaking
+  code that relies on the previous behavior) when you upgrade the
+  [language version][] of your code.
+  
+  
+  _These are marked "**Language versioned**"_.
+* **Deprecations**: The Dart SDK maintains compatibility for deprecated code,
+  with a warning. Deprecations are then completely removed in a subsequent release,
+  breaking any code that relies on the previous behavior.
+  
+  _These are marked "**Deprecated**" and "**Removed**", respectively_.
+* **Experimental**: Part of the release but not yet treated as stable in the SDK,
+  and can break from one version to another. Experimental changes do not
+  always have a corresponding breaking change issue, but may have more detail in
+  the [SDK changelog][changelog].
+
+  _These are marked "**Experimental**", possibly in conjunction with another change type_.
+
+If you have questions or concerns about any of these breaking changes, please 
+comment on the breaking change issue linked from the relevant entry.
+To be notified about future breaking changes, join the [Dart announce][] group.
+
+[breaking change policy]: https://github.com/dart-lang/sdk/blob/main/docs/process/breaking-changes.md
+[changelog]: https://github.com/dart-lang/sdk/blob/main/CHANGELOG.md
+[sdk]: /get-dart
+[language version]: /guides/language/evolution#language-versioning
+[Dart announce]: {{site.announce}}
+
+{% comment %}
+Create new section from these headers for each release.
+If no changes exist in a section (e.g. Language, `dart:async`, etc.),
+don't include the section header.
+
+## x.x.x
+
+### Language {:.no_toc}
+
+### Libraries {:.no_toc}
+
+#### (`dart:core`, `package:js`, etc)
+
+### Tools {:.no_toc}
+
+#### (Dart VM, Pub, Linter, `dart2js`, etc)
+{% endcomment %}
+
+## 3.4.0
+
+**Tentative**<br>
+The following changes are expected to be included in the 3.4.0 stable release,
+but the final list will likely change before then.
+To reduce the potential impact of these changes, consider
+accounting for them before the 3.4.0 release.
+
+### Language {:.no_toc}
+
+* [The pattern context type schema for cast patterns
+  is now `_` (the unknown type) instead of `Object?`][54640].
+
+[54640]: https://github.com/dart-lang/sdk/issues/54640
+
+### Libraries {:.no_toc}
+
+#### `dart:cli`
+
+* **Experimental** **Removed**: [The `waitFor` function][52121]
+  has been removed.
+
+[52121]: https://github.com/dart-lang/sdk/issues/52121
+
+#### `dart:html`, `dart:indexed:db`, `dart:svg`, `dart:web_audo`, `dart:web_gl`
+
+- These libraries are now marked as legacy and
+  will see less support in the future.
+  New projects should prefer to use [`package:web`][] and `dart:js_interop`.
+
+[`package:web`]: {{site.pub-pkg}}/web
+
+#### `dart:js`
+
+- This library is now marked as legacy and will see less support in the future.
+  Usages should be migrated to `dart:js_interop` and `dart:js_interop_unsafe`.
+  To learn more, check out [`/go/next-gen-js-interop`][].
+
+[`/go/next-gen-js-interop`]: https://dart.dev/go/next-gen-js-interop
+
+#### `dart:js_util`
+
+- This library is now marked as legacy and will see less support in the future.
+  Usages should be migrated to `dart:js_interop` and `dart:js_interop_unsafe`.
+  To learn more, check out [`/go/next-gen-js-interop`][].
+
+[`/go/next-gen-js-interop`]: https://dart.dev/go/next-gen-js-interop
+
+#### `dart:typed_data`
+
+* **Deprecated**: [The unmodifiable view classes for typed data are deprecated][53128].
+  Instead of using the constructors of these classes, use
+  the new `asUnmodifiableView` methods on typed data lists.
+
+[53128]: https://github.com/dart-lang/sdk/issues/53218
+
+### Tools {:.no_toc}
+
+#### Production JavaScript compiler (dart2js)
+
+* **Experimental** **Deprecated**: You should now specify a format to
+  the `--dump-info` CLI option of either `binary` or `json`.
+  The `json` format is deprecated and might be removed in a future Dart release.
+
+#### Wasm compiler (dart2wasm)
+
+* **Experimental**: Various `dart compile wasm` CLI arguments have
+  been updated, removed, or replaced.
+  To learn more, run `dart compile wasm --verbose --help`.
+
+## 3.3.0
+
+### SDK {:.no_toc}
+
+* **Experimental** **Removed**: The following experiments are now retired as
+  they were released in Dart 3 and are no longer necessary with
+  a language version of 3.0 or greater.
+  Configuration of them should be removed from
+  analysis options, CLI commands, and IDE configurations.
+
+  * `patterns`
+  * `records`
+  * `class-modifers`
+  * `sealed-class`
+
+### Language {:.no_toc}
+
+* [An abstract getter is now considered promotable if
+  there are no conflicting declarations][54056].
+
+[54056]: https://github.com/dart-lang/sdk/issues/54056
+
+### Libraries {:.no_toc}
+
+#### `dart:cli`
+
+* **Experimental** **Deprecated**: [The `waitFor` function][52121]
+  remains deprecated for another release and is set for removal in Dart 3.4.
+
+[52121]: https://github.com/dart-lang/sdk/issues/52121
+
+#### `dart:ffi`
+
+* **Deprecated**: [The `elementAt` pointer arithmetic methods
+  on `Pointer` types are deprecated][54250].
+  Migrate to the `-` and `+` operators instead.
+* **Experimental** **Removed**: The previously deprecated
+  `@FfiNative` annotation has been removed. Usages should be
+  updated to use the `@Native` annotation.
+
+[54250]: https://github.com/dart-lang/sdk/issues/54250
+
+#### `dart:html`
+
+* Instead of using `HttpRequest` directly,
+  it is now recommended to use [`package:http`][].
+
+[`package:http`]: {{site.pub-pkg}}/http
+
+#### `dart:io`
+
+* Instead of using `HttpClient` directly,
+  it is now recommended to use [`package:http`][].
+
+[`package:http`]: {{site.pub-pkg}}/http
+
+#### `dart:js_interop`
+
+* **Experimental**: JS types like `JSAny` have
+  [new compiler-specific representation types][52687].
+* **Experimental**: User-defined `@staticInterop` classes can
+  [no longer implement `JSAny` or `JSObject`][52687].
+  Usages should be migrated to `JSObject.fromInteropObject` or
+  be defined as extension types.
+* **Experimental**: `JSArray` and `JSPromise` now have generic parameters.
+* **Experimental**: Various extension members were moved or renamed.
+  To learn about the updated extensions, reference
+  `JSAnyUtilityExtension` and `JSAnyOperatorExtension`.
+
+[52687]: https://github.com/dart-lang/sdk/issues/52687
+
+#### `dart:typed_data`
+
+* [The unmodifiable view classes for typed data will
+  be deprecated in Dart 3.4][53128].
+  Instead of using the constructors of these classes, use
+  the new `asUnmodifiableView` methods on typed data lists.
+
+[53128]: https://github.com/dart-lang/sdk/issues/53218
+
+#### `dart:nativewrappers`
+
+* **Experimental**: [All native wrapper classes are now marked `base`][51896]
+  so that none of their subtypes can be implemented.
+
+[51896]: https://github.com/dart-lang/sdk/issues/51896
+
+### Tools {:.no_toc}
+
+#### Production JavaScript compiler (dart2js)
+
+* [The `Invocation` that is passed to `noSuchMethod` no longer
+  has a minified `memberName`][54201], even when compiled with `--minify`.
+
+[54201]: https://github.com/dart-lang/sdk/issues/54201
+
+#### Wasm compiler (dart2wasm)
+
+* **Experimental**: [Disallow importing legacy JS interop libraries][54004].
+  Prefer using `dart:js_interop` and `dart:js_interop_unsafe` instead.
+
+[54004]: https://github.com/dart-lang/sdk/issues/54004
+
+#### Analyzer
+
+* **Experimental**: Invalid `dart doc` comment directives are
+  now reported by the analyzer.
+* Due to [improvements in type promotion][54056], the following analyzer
+  diagnostics might trigger on existing code that previously passed analysis:
+
+  * `unnecessary_non_null_assertion`
+  * `unnecessary_cast`
+  * `invalid_null_aware_operator`
+
+[54056]: https://github.com/dart-lang/sdk/issues/54056
+
+#### Linter
+
+* The `iterable_contains_unrelated_type` and
+  `list_remove_unrelated_type` lints were removed.
+  Consider migrating to the expanded
+  [`collection_methods_unrelated_type`][] lint.
+* The following lints are removed due to no longer being
+  necessary with sound null safety. You should remove configuration of them
+  from your `analysis_options.yaml` files and any ignore comments.
+  
+  * `always_require_non_null_named_parameters`
+  * `avoid_returning_null`
+  * `avoid_returning_null_for_future`
+
+[`collection_methods_unrelated_type`]: /tools/linter-rules/collection_methods_unrelated_type
+
+## 3.2.0
+
+### Language {:.no_toc}
+
+* **Language versioned**: [Changed the split point for refutable patterns][53167]
+  to the top level pattern so type promotion in if-case statements is consistent
+  regardless of whether the scrutinee might throw an exception.
+
+### Libraries {:.no_toc}
+
+#### `dart:cli`
+
+* **Experimental** **Deprecated**: [The `waitFor` function.][52121]
+
+#### `dart:convert`
+
+* [Changed return types of `utf8.encode()` and `Utf8Codec.encode()`][52801]
+ from `List<int>` to `Uint8List`.
+
+#### `dart:developer`
+
+* **Deprecated**: The `Service.getIsolateID` method.
+
+#### `dart:ffi`
+
+* [Changed `NativeCallable.nativeFunction` so calls now throw an error if
+  the receiver is already closed][53311], instead of returning `nullptr`.
+
+#### `dart:io`
+
+* [Eliminated trailing whitespace from HTTP headers][53005].
+* [Inserted a space at the fold point of folded header values][53227]
+  that `HttpClientResponse.headers` and `HttpRequest.headers` return.
+
+#### `dart:js_interop`
+
+* **Experimental** **Removed**: `JSNumber.toDart` in favor of `toDartDouble` and
+  `toDartInt`.
+* **Experimental** **Removed**: `Object.toJS` in favor of `Object.toJSBox.`
+* **Experimental**: Restricted external JS interop APIs using `dart:js_interop`
+  to a set of allowed types.
+* **Experimental**: Prohibited use of `isNull` and `isUndefined` on dart2wasm.
+* **Experimental**: Changed `typeofEquals` and `instanceof` APIs to both return
+  bool instead of `JSBoolean`.
+  Also, `typeofEquals` now takes `String` instead of `JSString`.
+* **Experimental**: Changed `JSAny` and `JSObject` types to only implementable,
+  not extendable, by user `@staticInterop` types.
+* **Experimental**: Changed `JSArray.withLength` to take `int` instead of `JSNumber`.
+
+### Tools {:.no_toc}
+
+#### Development JavaScript compiler (DDC)
+
+* [Added interceptors for JavaScript `Symbol` and `BigInt` types][53106];
+  they should no longer be used with `package:js` classes.
+
+#### Production JavaScript compiler (dart2js)
+
+* [Added interceptors for JavaScript `Symbol` and `BigInt` types][53106];
+  they should no longer be used with `package:js` classes.
+
+#### Analyzer
+
+* **Language versioned**: [Private final field promotion][2020] might cause the following
+  analyzer warnings to trigger on existing code that previously passed analysis:
+  
+  * [`unnecessary_non_null_assertion`](/tools/diagnostic-messages#unnecessary_non_null_assertion)
+  * [`invalid_null_aware_operator`](/tools/diagnostic-messages#invalid_null_aware_operator)
+  * [`unnecessary_cast`](/tools/diagnostic-messages#unnecessary_cast)
+
+  ```dart
+  class C {
+    final num? _x = null;
+
+    void test() {
+      if (_x != null) {
+        print(_x! * 2); // unnecessary_non_null_assertion
+        print(_x?.abs()); // invalid_null_aware_operator
+      }
+      if (_x is int) {
+        print((_x as int).bitLength); // unnecessary_cast
+      }
+    }
+  }
+  ```
+
+[53167]: https://github.com/dart-lang/sdk/issues/53167
+[52121]: https://github.com/dart-lang/sdk/issues/52121
+[52801]: https://github.com/dart-lang/sdk/issues/52801
+[53311]: https://github.com/dart-lang/sdk/issues/53311
+[53005]: https://github.com/dart-lang/sdk/issues/53005
+[53227]: https://github.com/dart-lang/sdk/issues/53227
+[53106]: https://github.com/dart-lang/sdk/issues/53106
+[2020]: https://github.com/dart-lang/language/issues/2020
+
+
+## 3.1.0
+
+### Libraries {:.no_toc}
+
+#### `dart:async`
+
+* [Added `interface` modifier to purely abstract classes:][52334]
+ `MultiStreamController`, `StreamConsumer`, `StreamIterator` and `StreamTransformer`.
+
+#### `dart:io`
+
+* [Added `sameSite` to the `Cookie` class, and added the class `SameSite`][51486].
+* [`FileSystemEvent` is `sealed`][52027]. This means `FileSystemEvent` cannot be 
+  extended or implemented.
+
+#### `dart:js_interop`
+
+* **Experimental** **Removed**: `ObjectLiteral`; create an object literal with
+  no named members using `{}.jsify()`.
+
+#### `package:js`
+
+* `external` `@staticInterop` members and `external` extension members can no
+  longer be used as tear-offs. Declare a closure or a non-`external` method that
+  calls these members, and use that instead.
+* `external` `@staticInterop` members and `external` extension members will
+  generate slightly different JS code for methods that have optional parameters.
+
+[52334]: https://github.com/dart-lang/sdk/issues/52334
+[51486]: https://github.com/dart-lang/sdk/issues/51486
+[52027]: https://github.com/dart-lang/sdk/issues/52027
+
+## 3.0.0
+
+:::tip
+The [Dart 3.0 migration guide][dart3] covers the complete details
+on all the changes in this section.
+:::
+
+### Language {:.no_toc}
+
+* **Language versioned**: Changed interpretation of [switch cases] from constant
+  expressions to patterns.
+
+* **Language versioned**: Class declarations from libraries that have been upgraded
+  to Dart 3.0 [can no longer be used as mixins by default][mixin class].
+
+* [Dart reports a compile-time error][50902] if a `continue` statement targets
+  a [label] that is not a loop (`for`, `do` and `while` statements) or a `switch`
+  member.
+
+### Libraries {:.no_toc}
+
+* The following existing classes have been made mixin classes:
+  `Iterable`, `IterableMixin`, `IterableBase`, `ListMixin`, `SetMixin`, `MapMixin`,
+  `LinkedListEntry`, `StringConversionSink`.
+
+#### `dart:core`
+
+* **Deprecated**: [Deprecated APIs][49529].
+
+#### `dart:async`
+
+* **Removed**: [Removed the deprecated][49529] [`DeferredLibrary`][] class.
+
+#### `dart:collection`
+
+* **Language versioned**: [Changes to platform libraries][collection].
+
+#### `dart:developer`
+
+* **Removed**: [Removed the deprecated][49529] [`MAX_USER_TAGS`][] constant.
+  Use [`maxUserTags`][] instead.
+* **Removed**: [Removed the deprecated][50231] [`Metrics`][], [`Metric`][], [`Counter`][],
+  and [`Gauge`][] classes as they have been broken since Dart 2.0.
+
+#### `dart:ffi`
+
+* **Experimental** **Deprecated**: The `@FfiNative` annotation is
+  now deprecated. Usages should be updated to use the `@Native` annotation.
+
+#### `dart:html`
+
+* **Removed**: [Removed the deprecated `registerElement` and `registerElement2`][49536]
+  methods in `Document` and `HtmlDocument`.
+
+#### `dart:math`
+
+* **Language versioned**: The `Random` interface can only be implemented,
+  not extended.
+
+#### `dart:io`
+
+* [Updated `NetworkProfiling`][51035] to accommodate new `String` ids that are
+  introduced in vm_service:11.0.0
+
+[dart3]: /resources/dart-3-migration/
+[switch cases]: https://dart.dev/language/branches#switch
+[mixin class]: https://dart.dev/language/mixins#class-mixin-or-mixin-class
+[label]: https://dart.dev/language/branches#switch
+[50902]: https://github.com/dart-lang/sdk/issues/50902
+[collection]: /resources/dart-3-migration#dart-collection
+[49529]: https://github.com/dart-lang/sdk/issues/49529
+[`DeferredLibrary`]: https://api.dart.dev/stable/2.18.4/dart-async/DeferredLibrary-class.html
+[`deferred as`]: https://dart.dev/guides/language/language-tour#deferred-loading
+[`MAX_USER_TAGS`]: https://api.dart.dev/stable/dart-developer/UserTag/MAX_USER_TAGS-constant.html
+[`maxUserTags`]: https://api.dart.dev/beta/2.19.0-255.2.beta/dart-developer/UserTag/maxUserTags-constant.html
+[50231]: https://github.com/dart-lang/sdk/issues/50231
+[`Metrics`]: https://api.dart.dev/stable/2.18.2/dart-developer/Metrics-class.html
+[`Metric`]: https://api.dart.dev/stable/2.18.2/dart-developer/Metric-class.html
+[`Counter`]: https://api.dart.dev/stable/2.18.2/dart-developer/Counter-class.html
+[`Gauge`]: https://api.dart.dev/stable/2.18.2/dart-developer/Gauge-class.html
+[49536]: https://github.com/dart-lang/sdk/issues/49536
+[51035]: https://github.com/dart-lang/sdk/issues/51035
+
+
+## 2.19.0
+
+### Language {:.no_toc}
+
+* [Flagged additional code as unreachable][49635] due to types `Null` and `Never`.
+* [Don't delegate inaccessible private names to `noSuchMethod`][49687].
+* [Report a compile-time error][50383] for all cyclic dependencies during
+  top-level type inference.
+
+### Libraries {:.no_toc}
+
+#### `dart:convert`
+
+* **Removed**: [The previously deprecated API][34233] [`DEFAULT_BUFFER_SIZE`] in `JsonUtf8Encoder`
+  has been removed.
+
+#### `dart:developer`
+
+* **Removed**: [Removed previously deprecated APIs][34233] `kInvalidParams`,
+  `kExtensionError`, `kExtensionErrorMax`, and `kExtensionErrorMin` in
+  [`ServiceExtensionResponse`].
+
+#### `dart:ffi`
+
+* [Changed the runtime type argument of `Pointer` to `Never`][49935] in
+  preparation of completely removing the runtime type argument. 
+  Changed `Pointer.toString` to not report any type argument.
+
+#### `dart:io`
+
+* [Disallow negative or hexadecimal content-length headers][49305].
+* [`File.create` now takes new optional `exclusive` `bool` parameter][49647],
+  and when it is `true` the operation will fail if target file already exists.
+* Calling `ResourceHandle.toFile()`, `ResourceHandle.toSocket()`,
+  `ResourceHandle.toRawSocket()` or `ResourceHandle.toRawDatagramSocket()`,
+  more than once [now throws a `StateError`][49878].
+
+#### `dart:isolate`
+
+* Reverted [`SendPort.send`] back to strict checks on contents of messages when
+  sending messages between isolates that are not known to share the same code.
+
+#### `dart:mirrors`
+
+* [Removed APIs][34233] [`MirrorsUsed`] and [`Comment`].
+
+#### `package:js`
+
+* Breaking changes to the preview feature `@staticInterop`:
+  * Disallowed classes with this annotation from using `external`
+    generative constructors. See [48730] and [49941] for more details.
+  * [Disallowed classes with this annotation's external extension members from
+    using type parameters][49350].
+  * Classes with this annotation should also have the `@JS` annotation.
+  * Classes with this annotation can not be implemented by classes without this
+    annotation.
+
+#### `dart2js`
+
+* [`dart2js` no longer supports HTTP URIs as inputs][49473].
+
+[49635]: https://github.com/dart-lang/sdk/issues/49635
+[49687]: https://github.com/dart-lang/sdk/issues/49687
+[50383]: https://github.com/dart-lang/sdk/issues/50383
+[34233]: https://github.com/dart-lang/sdk/issues/34233
+[`ServiceExtensionResponse`]: https://api.dart.dev/stable/2.17.6/dart-developer/ServiceExtensionResponse-class.html#constants
+[49935]: https://github.com/dart-lang/sdk/issues/49935
+[49305]: https://github.com/dart-lang/sdk/issues/49305
+[49647]: https://github.com/dart-lang/sdk/issues/49647
+[49878]: https://github.com/dart-lang/sdk/issues/49878
+[`SendPort.send`]: https://api.dart.dev/stable/dart-isolate/SendPort/send.html
+[34233]: https://github.com/dart-lang/sdk/issues/34233
+[49473]: https://github.com/dart-lang/sdk/issues/49473
+[48730]: https://github.com/dart-lang/sdk/issues/48730
+[49941]: https://github.com/dart-lang/sdk/issues/49941
+[49350]: https://github.com/dart-lang/sdk/issues/49350
+
+
+## 2.18.0
+
+### Language {:.no_toc}
+
+* [Removed support for mixin of classes that don't extend `Object`][48167].
+
+### Libraries {:.no_toc}
+
+#### `dart:io`
+
+* [Changed the `uri` property of `RedirectException` in `dart:io` to be nullable][49045].
+* [Removed constants in `dart:io` networking APIs following the `SCREAMING_CAPS`
+  convention][34218].
+* [The Dart VM no longer automatically restores the initial terminal settings][45630]
+  upon exit.
+
+### Tools {:.no_toc}
+
+* [Fully discontinued the `.packages` file][48272]. 
+
+#### Dart command line
+
+* [Removed the standalone `dart2js` and `dartdevc` tools][46100].
+* [Removed the standalone `dartanalyzer` tool][46100].
+
+[48167]: https://github.com/dart-lang/sdk/issues/48167
+[49045]: https://github.com/dart-lang/sdk/issues/49045
+[34218]: https://github.com/dart-lang/sdk/issues/34218
+[45630]: https://github.com/dart-lang/sdk/issues/45630
+[48272]: https://github.com/dart-lang/sdk/issues/48272
+[46100]: https://github.com/dart-lang/sdk/issues/46100
+
+## 2.17.0
+
+### Libraries {:.no_toc}
+
+#### `dart:io`
+
+* [Added new `connectionFactory` property to `HttpClient`][47887].
+* [Added new `keyLog` property to `HttpClient`][48093], which allows TLS keys to
+  be logged for debugging purposes.
+* [Removed constants in `dart:io` following the `SCREAMING_CAPS`][34218]
+* [Added a new `allowLegacyUnsafeRenegotiation` property to `SecurityContext`][48513],
+  which allows TLS renegotiation for client secure sockets.
+
+### Tools {:.no_toc}
+
+#### Dart command line
+
+* **Deprecated**: [Deprecated the standalone `dart2js` tool][46100].
+* **Deprecated**: [Deprecated the standalone `dartdevc` tool][46100].
+* **Removed**: [Removed the standalone `dartdoc` tool][46100].
+
+[47887]: https://github.com/dart-lang/sdk/issues/47887
+[48093]: https://github.com/dart-lang/sdk/issues/48093
+[34218]: https://github.com/dart-lang/sdk/issues/34218
+[48513]: https://github.com/dart-lang/sdk/issues/48513
+[46100]: https://github.com/dart-lang/sdk/issues/46100
+
+## 2.16.0
+
+### Libraries {:.no_toc}
+
+#### `dart:io`
+
+* On Windows, [`Directory.rename` will no longer delete a directory][47653] if
+  `newPath` specifies one. Instead, a `FileSystemException` will be thrown.
+* **Removed**: [Removed the `Platform.packageRoot` API][47769].
+
+#### `dart:isolate`
+
+* **Removed**: [Removed the `Isolate.packageRoot` API][47769].
+
+### Tools {:.no_toc}
+
+#### Dart command line
+
+* **Deprecated**: [Deprecated the standalone `dartanalyzer` tool][46100].
+* **Deprecated**: [Deprecated the standalone `dartdoc` tool][46100].
+* **Removed**: [Removed the deprecated standalone `pub` tool][46100].
+
+[47653]: https://github.com/dart-lang/sdk/issues/47653
+[47769]: https://github.com/dart-lang/sdk/issues/47769
+[46100]: https://github.com/dart-lang/sdk/issues/46100
+
+## 2.15.0
+
+### Libraries {:.no_toc}
+
+#### `dart:io`
+
+* [Updated the `SecurityContext` class][46875] to set the minimum
+  TLS protocol version to TLS1_2_VERSION (1.2) instead of TLS1_VERSION.
+
+#### `dart:web_sql`
+
+* [Completely deleted the `dart:web_sql` library][46316].
+
+#### `dart:html`
+
+* [Removed `window.openDatabase`][46316] (related to `dart:web_sql` deletion above).
+
+### Tools {:.no_toc}
+
+#### Dart command line
+
+* [Removed the standalone `dart2native` tool][46100].
+* Removed the standalone `dartfmt` tool.
+
+#### Dart VM
+
+* [Removed support for `dart-ext:`-style native extensions][45451]
+* [Grouped isolates spawned via the `Isolate.spawn()` API][46754] to operate on the
+  same managed heap, and therefore share various VM-internal data structures.
+
+[46875]: https://github.com/dart-lang/sdk/issues/46875
+[46316]: https://github.com/dart-lang/sdk/issues/46316
+[45451]: https://github.com/dart-lang/sdk/issues/45451
+[46754]: https://github.com/dart-lang/sdk/issues/46754
+
+## 2.14.0
+
+### Libraries {:.no_toc}
+
+#### `dart:io`
+
+* The setter callbacks `.authenticate` and `.authenticateProxy` in `HttpClient`
+  must now accept a nullable `realm` argument (for pre-migrated null safe code).
+
+#### `dart:typed_data`
+
+* Most types exposed by this library [can no longer be extended, implemented or
+  mixed-in][45115].
+
+### Tools {:.no_toc}
+
+#### Dart VM
+
+* Expandos, and the `object` parameters of `Dart_NewWeakPersistentHandle` and 
+  `Dart_NewFinalizableHandle`, [no longer accept `Pointer` and subtypes of `Struct`][45071] 
+
+#### Dart command line
+
+* [Deprecated the standalone `dart2native` tool][46100]
+* Deprecated the standalone `dartfmt` tool.
+
+#### `dart2js`
+
+* [`dart2js` no longer supports legacy browsers][46545], because it emits ES6+
+  JavaScript by default.
+
+#### Dart Dev Compiler (DDC)
+
+* [Changed subtyping relations of `package:js` classes][44154] to be more correct and
+  consistent with Dart2JS.
+
+[45115]: https://github.com/dart-lang/sdk/issues/45115
+[45071]: https://github.com/dart-lang/sdk/issues/45071
+[46545]: https://github.com/dart-lang/sdk/issues/46545
+[44154]: https://github.com/dart-lang/sdk/issues/44154
+
+
+## 2.13.0
+
+### Libraries {:.no_toc}
+
+#### `package:js`
+
+* [No longer valid][44211] to use a `String` that matches an `@Native` annotation
+  in an `@JS()` annotation for a non-anonymous JS interop class.
+
+[44211]: https://github.com/dart-lang/sdk/issues/44211
+
+## 2.12.0
+
+### Language {:.no_toc}
+
+* [Null safety] is now enabled by default in all code that
+  has not opted out.
+* [Fixed an implementation bug][44660] where `this` would sometimes undergo type
+  promotion in extensions.
+
+### Libraries {:.no_toc}
+
+#### `dart:ffi`
+
+* [Deprecated invocations with a generic `T`][44621] of `sizeOf<T>`,
+  `Pointer<T>.elementAt()`, `Pointer<T extends Struct>.ref`, and
+  `Pointer<T extends Struct>[]`
+* [Deprecated `allocate` in `package:ffi`][44621], as it will no longer be
+  able to invoke `sizeOf<T>` generically.
+* [Deprecated subtypes of `Struct` without any native member][44622].
+
+### Tools {:.no_toc}
+
+#### Dart VM
+
+* [`Dart_WeakPersistentHandle` no longer auto-deletes itself][42312] when the
+  referenced object is garbage collected to avoid race conditions.
+* [Renamed `Dart_WeakPersistentHandleFinalizer` to `Dart_HandleFinalizer`][42312] 
+  and removed its `handle` argument.
+
+#### Pub 
+
+* [The Dart SDK constraint is now **required** in `pubspec.yaml`][44072].
+
+[Null safety]: https://dart.dev/null-safety/understanding-null-safety
+[44660]: https://github.com/dart-lang/sdk/issues/44660
+[44621]: https://github.com/dart-lang/sdk/issues/44621
+[42312]: https://github.com/dart-lang/sdk/issues/42312
+[44622]: https://github.com/dart-lang/sdk/issues/44622
+[44072]: https://github.com/dart-lang/sdk/issues/44072
+
+## 2.10.0
+
+### Tools {:.no_toc}
+
+#### Dart VM
+
+* [Renamed `dart_api_dl.cc` to `dart_api_dl.c`][42982] and changed to a pure C file.
+
+[42982]: https://github.com/dart-lang/sdk/issues/42982
+
+## 2.9.0
+
+### Libraries {:.no_toc}
+
+#### `dart:convert`
+
+* When encoding a string containing unpaired surrogates as UTF-8, [the unpaired
+  surrogates will be encoded as replacement characters][41100] (`U+FFFD`).
+* When decoding UTF-8, [encoded surrogates will be treated as malformed input][41100].
+* [Changed the number of replacement characters emitted][41100] for malformed
+  input sequences to match the [WHATWG encoding standard][] when decoding UTF-8
+  with `allowMalformed: true`.
+
+#### `dart:html`
+
+* `CssClassSet.add()` and `CssClassSet.toggle` now return `false` instead of
+   `null` if the `CssClassSet` corresponds to multiple elements. 
+
+#### `dart:mirrors`
+
+* [Web compilers (dart2js and DDC) now produce a compile-time error][42714] if
+  `dart:mirrors` is imported.
+
+### Tools {:.no_toc}
+
+#### Dart VM
+
+* When printing a string using the `print` function, [the default implementation
+  will print any unpaired surrogates in the string as replacement characters][41100]
+  (`U+FFFD`).
+* The `Dart_StringToUTF8` function in the Dart API [will convert unpaired
+  surrogates into replacement characters][41100].
+
+
+[41100]: https://github.com/dart-lang/sdk/issues/41100
+[whatwg encoding standard]: https://encoding.spec.whatwg.org/#utf-8-decoder
+[42714]: https://github.com/dart-lang/sdk/issues/42714
+
+## 2.8.1
+
+### Language {:.no_toc}
+
+* [Fixed an implementation bug][40675] where local variable inference would
+  incorrectly use the promoted type of a type variable.
+* [Fixed an implementation bug][41362] surrounding the clauses
+  `implements Function`, `extends Function`, or `with Function` no longer having
+  an effect since Dart 2.0.0.
+
+### Libraries {:.no_toc}
+
+#### `dart:async`
+
+* [Changed the return type of `StreamSubscription.cancel()` to `Future<void>`][40676].
+* [Split the `runZoned()` function into two functions][40681]:
+  `runZoned()` and `runZonedGuarded()`, where the latter has a
+  required `onError` parameter, and the former has none.
+* Errors passed to `Completer.completeError()`, `Stream.addError()`,
+  `Future.error()`, etc. [can no longer be `null`][40683].
+* [Made stack traces non-null ][40130].
+
+#### `dart:core`
+
+* Three members on `RuneIterator` [no longer return `null`][40674] when accessed
+  before the first call to `moveNext()`.
+* The `String.fromEnvironment()` default value for `defaultValue` 
+  [is now an empty string instead of `null`][40678].
+* The default value for `int.fromEnvironment()`'s `defaultValue` parameter
+  [is now zero][40678].
+
+#### `dart:ffi`
+
+* Changed `Pointer.asFunction()` and `DynamicLibrary.lookupFunction()` to
+  extension methods.
+
+#### `dart:io`
+
+* [Changed the signature of `HttpHeaders` methods][33501] `add()` and `set`.
+* [The `Socket` class now throws a `SocketException`][40702] if the socket has
+  been explicitly destroyed or upgraded to a secure socket upon setting or getting socket options.
+* [The `Process` class now throws a `StateError`][40483]
+  if the process is detached (`ProcessStartMode.detached` and
+  `ProcessStartMode.detachedWithStdio`) upon accessing the `exitCode` getter.
+* [The `Process` class now also throws][40483] when not connected to the child
+  process's stdio (`ProcessStartMode.detached` and `ProcessStartMode.inheritStdio`) upon accessing the `stdin`, `stdout`, and `stderr` getters.
+* The dummy object returned if `FileStat.stat()` or `FileStat.statSync()` fail
+  [now contains Unix epoch timestamps][40706] instead of `null` for the `accessed`,
+  `changed`, and `modified` getters.
+* [The `HeaderValue` class now parses more strictly][40709] in two invalid edge cases.
+
+### Tools {:.no_toc}
+
+#### Dart Dev Compiler (DDC)
+
+We fixed several inconsistencies between DDC and Dart2JS so that users less
+frequently encounter code that is accepted by one compiler but then fails in the
+other.
+
+* Deleted the legacy (analyzer based) version of [DDC][ddc].
+* Functions passed to JavaScript using the recommended `package:js` interop
+  specification must now be wrapped with a call to `allowInterop`. 
+* Constructors in `@JS()` classes must be marked with `external`.
+
+#### `dart2js`
+
+* Corresponding type parameter bounds now only need to be mutual
+  subtypes rather than structurally equal up to renaming of bound type variables
+  and equating all top types.
+* Types are now [normalized].
+* Constructors in `@JS()` classes must be marked with `external`.
+* Completely removed the `--package-root` flag, which was hidden and disabled
+  in Dart 2.0.0.
+
+[40675]: https://github.com/dart-lang/sdk/issues/40675
+[41362]: https://github.com/dart-lang/sdk/issues/41362
+[40676]: https://github.com/dart-lang/sdk/issues/40676
+[40681]: https://github.com/dart-lang/sdk/issues/40681
+[40683]: https://github.com/dart-lang/sdk/issues/40683
+[40130]: https://github.com/dart-lang/sdk/issues/40130
+[40674]: https://github.com/dart-lang/sdk/issues/40674
+[40678]: https://github.com/dart-lang/sdk/issues/40678
+[33501]: https://github.com/dart-lang/sdk/issues/33501
+[40702]: https://github.com/dart-lang/sdk/issues/40702
+[40483]: https://github.com/dart-lang/sdk/issues/40483
+[40706]: https://github.com/dart-lang/sdk/issues/40706
+[40709]: https://github.com/dart-lang/sdk/issues/40709
+[ddc]: https://github.com/dart-lang/sdk/issues/38994
+[normalized]: https://github.com/dart-lang/language/blob/main/resources/type-system/normalization.md
+
+## 2.7.1
+
+* [The Dart SDK for macOS is now only available for x64][39810].
+
+[39810]: https://github.com/dart-lang/sdk/issues/39810
+
+## 2.7.0
+
+### Language {:.no_toc}
+
+* [Static extension members are accessible when imported with a prefix][671].
+
+### Libraries {:.no_toc}
+
+#### `dart:io`
+
+* Added `IOOverrides.serverSocketBind` to aid in writing tests that wish to mock
+  `ServerSocket.bind`.
+
+## 2.6.0
+
+### Language {:.no_toc}
+
+* [Changed inference when using `Null` values in a `FutureOr` context][37985].
+  Namely, constraints of the forms similar to `Null` <: `FutureOr<T>` now yield
+  `Null` as the solution for `T`.
+
+### Libraries {:.no_toc}
+
+#### `dart:ffi`
+
+* The API now makes use of static extension members. 
+* Removed memory management `Pointer.allocate` and `Pointer.free`.
+* `Pointer.offsetBy` was removed, use `cast` and `elementAt` instead.
+
+[671]: https://github.com/dart-lang/language/issues/671
+[37985]: https://github.com/dart-lang/sdk/issues/37985
+
+## 2.5.0
+
+### Libraries {:.no_toc}
+
+* Various methods and properties across various core libraries, which used
+  to declare a return type of `List<int>`, were [updated to declare a return type
+  of `Uint8List`][36900].
+
+#### `dart:io`
+
+* The `Cookie` class's constructor's `name` and `value` optional positional
+  parameters [are now mandatory][37192].
+* [The `Cookie` class's `name` and `value` setters now validate][37192]
+  that the strings are made from the allowed character set and are not null.
+
+### Tools {:.no_toc}
+
+#### Pub
+
+* Packages published to [pub.dev](https://pub.dev) [can no longer contain git
+  dependencies][36765].
+
+[36900]: https://github.com/dart-lang/sdk/issues/36900
+[37192]: https://github.com/dart-lang/sdk/issues/37192
+[37192]: https://github.com/dart-lang/sdk/issues/37192
+[36765]: https://github.com/dart-lang/sdk/issues/36765
+
+## 2.4.0
+
+### Language {:.no_toc}
+
+* [Covariance of type variables used in super-interfaces is now enforced][35097]. 
+
+### Libraries {:.no_toc}
+
+#### `dart:isolate`
+
+* `Isolate.resolvePackageUri` will always throw an `UnsupportedError` when
+  compiled with dart2js or DDC.
+
+#### `dart:async`
+
+* [Fixed a bug in the `StreamIterator` class][36382] where `await for` allowed
+  `null` as a stream.
+
+[35097]: https://github.com/dart-lang/sdk/issues/35097
+[36382]: https://github.com/dart-lang/sdk/issues/36382
+
+## 2.2.0
+
+### Libraries {:.no_toc}
+
+#### `package:kernel`
+
+* The `klass` getter on the `InstanceConstant` class in the
+  Kernel AST API has been renamed to `classNode` for consistency.
+* [Updated `Link` implementation][33966] to utilize true symbolic
+  links instead of junctions on Windows.
+
+[33966]: https://github.com/dart-lang/sdk/issues/33966
+
+## 2.1.1
+
+### Libraries {:.no_toc}
+
+#### `dart:io`
+
+* [Added to a closed `IOSink` now throws a `StateError`][29554].
+
+[29554]: https://github.com/dart-lang/sdk/issues/29554
+
+### Tools {:.no_toc}
+
+#### Dart VM
+
+* [Fixed a soundness hole when using `dart:mirrors`][35611] to reflectively
+  invoke a method in an incorrect way that violates its static types.
+
+[29554]: https://github.com/dart-lang/sdk/issues/29554
+[35611]: https://github.com/dart-lang/sdk/issues/35611
+
+## 2.1.0
+
+### Language {:.no_toc}
+
+* A number of static errors that should have been detected
+  and reported were not supported in 2.0.0. These are reported now, which means
+  existing incorrect code may show new errors:
+  * [Mixins must correctly override their superclasses][34235].
+  * [Implicit type arguments in extends clauses must satisfy the class bounds][34532].
+  * [Instance members should shadow prefixes][34498].
+  * [Constructor invocations must use valid syntax, even with optional `new`][34403].
+  * [Type arguments to generic typedefs must satisfy their bounds][33308].
+  * [Classes can't implement FutureOr][33744].
+  * [Abstract methods may not unsoundly override a concrete method][32014].
+  * [Constant constructors cannot redirect to non-constant constructors][34161].
+  * [Setters with the same name as the enclosing class aren't allowed][34225].
+
+### Tools {:.no_toc}
+
+#### `dart2js`
+
+* Duplicate keys in a const map are not allowed and produce a compile-time error.
+
+[32014]: https://github.com/dart-lang/sdk/issues/32014
+[33308]: https://github.com/dart-lang/sdk/issues/33308
+[33744]: https://github.com/dart-lang/sdk/issues/33744
+[34161]: https://github.com/dart-lang/sdk/issues/34161
+[34225]: https://github.com/dart-lang/sdk/issues/34225
+[34235]: https://github.com/dart-lang/sdk/issues/34235
+[34403]: https://github.com/dart-lang/sdk/issues/34403
+[34498]: https://github.com/dart-lang/sdk/issues/34498
+[34532]: https://github.com/dart-lang/sdk/issues/34532
+
+## 2.0.0
+
+### Language {:.no_toc}
+
+* Replaced the unsound optional static type system with a sound static type
+  system using type inference and runtime checks, formerly called [strong mode].
+* [Functions marked `async` now run synchronously][30345] until the first
+  `await` statement.
+
+### Libraries {:.no_toc}
+
+* Renamed constants in the core libraries from `SCREAMING_CAPS` to `lowerCamelCase`.
+* Added many new methods to core library classes that will need to be implemented
+  if you implement the interfaces of these classes.
+* `dart:isolate` and `dart:mirrors` are no longer supported when
+  using Dart for the web.
+
+### Tools {:.no_toc}
+
+#### Pub
+
+* Replaced pub's transformer-based build system with a [new build system][build system].
+
+[30345]: https://github.com/dart-lang/sdk/issues/30345
+[strong mode]: /guides/language/type-system
+[build system]: https://github.com/dart-lang/build
\ No newline at end of file
diff --git a/test_files/source/cloudflare workers runtime api fetch.md b/test_files/source/cloudflare workers runtime api fetch.md
new file mode 100644
index 0000000..9947235
--- /dev/null
+++ b/test_files/source/cloudflare workers runtime api fetch.md	
@@ -0,0 +1,88 @@
+---
+pcx_content_type: configuration
+title: Fetch
+meta:
+  description: An interface for asynchronously fetching resources via HTTP requests inside of a Worker.
+---
+
+# Fetch
+
+The [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) provides an interface for asynchronously fetching resources via HTTP requests inside of a Worker.
+
+{{<Aside type="note">}}
+
+Asynchronous tasks such as `fetch` must be executed within a [handler](/workers/runtime-apis/handlers/). If you try to call `fetch()` within [global scope](https://developer.mozilla.org/en-US/docs/Glossary/Global_scope), your Worker will throw an error. Learn more about [the Request context](/workers/runtime-apis/request/#the-request-context).
+
+{{</Aside>}}
+
+{{<Aside type="warning" header="Worker to Worker">}}
+
+Worker-to-Worker `fetch` requests are possible with [Service bindings](/workers/configuration/bindings/about-service-bindings/).
+
+{{</Aside>}}
+
+## Syntax
+
+{{<tabs labels="js/esm | js/sw">}}
+{{<tab label="js/esm" default="true">}}
+
+```js
+---
+highlight: [3-7]
+---
+export default {
+  async scheduled(event, env, ctx) {
+    return await fetch("https://example.com", {
+      headers: {
+        "X-Source": "Cloudflare-Workers",
+      },
+    });
+  },
+};
+```
+{{</tab>}}
+{{<tab label="js/sw">}}
+```js
+---
+highlight: [8]
+---
+addEventListener('fetch', event => {
+  // NOTE: can’t use fetch here, as we’re not in an async scope yet
+  event.respondWith(eventHandler(event));
+});
+
+async function eventHandler(event) {
+  // fetch can be awaited here since `event.respondWith()` waits for the Promise it receives to settle
+  const resp = await fetch(event.request);
+  return resp;
+}
+```
+{{</tab>}}
+{{</tabs>}}
+
+{{<definitions>}}
+
+- {{<code>}}fetch(resource, options {{<prop-meta>}}optional{{</prop-meta>}}){{</code>}} : {{<type-link href="/runtime-apis/response">}}Promise`<Response>`{{</type-link>}}
+
+  - Fetch returns a promise to a Response.
+
+{{</definitions>}}
+
+### Parameters
+
+{{<definitions>}}
+
+- [`resource`](https://developer.mozilla.org/en-US/docs/Web/API/fetch#resource) {{<type-link href="/workers/runtime-apis/request/">}}Request{{</type-link>}} | {{<type>}}string{{</type>}} | {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/URL">}}URL{{</type>}}
+
+- `options` {{<type-link href="/runtime-apis/request/#the-cf-property-requestinitcfproperties">}}options{{</type-link>}}
+  - An object that defines the content and behavior of the request.
+
+{{</definitions>}}
+
+## Related resources
+
+- [Example: use `fetch` to respond with another site](/workers/examples/respond-with-another-site/)
+- [Example: Fetch HTML](/workers/examples/fetch-html/)
+- [Example: Fetch JSON](/workers/examples/fetch-json/)
+- [Example: cache using Fetch](/workers/examples/cache-using-fetch/)
+- Write your Worker code in [ES modules syntax](/workers/reference/migrate-to-module-workers/) for an optimized experience.
diff --git a/test_files/source/cloudflare workers runtime api headers.md b/test_files/source/cloudflare workers runtime api headers.md
new file mode 100644
index 0000000..e2b6d2e
--- /dev/null
+++ b/test_files/source/cloudflare workers runtime api headers.md	
@@ -0,0 +1,58 @@
+---
+pcx_content_type: configuration
+title: Headers
+meta:
+  description: Access HTTP request and response headers.
+---
+
+# Headers
+
+## Background
+
+All HTTP request and response headers are available through the [Headers API](https://developer.mozilla.org/en-US/docs/Web/API/Headers).
+
+When a header name possesses multiple values, those values will be concatenated as a single, comma-delimited string value. This means that `Headers.get` will always return a string or a `null` value. This applies to all header names except for `Set-Cookie`, which requires `Headers.getAll`. This is documented below in [Differences](#differences).
+
+```js
+let headers = new Headers();
+
+headers.get('x-foo'); //=> null
+
+headers.set('x-foo', '123');
+headers.get('x-foo'); //=> "123"
+
+headers.set('x-foo', 'hello');
+headers.get('x-foo'); //=> "hello"
+
+headers.append('x-foo', 'world');
+headers.get('x-foo'); //=> "hello, world"
+```
+
+## Differences
+
+- Despite the fact that the `Headers.getAll` method has been made obsolete, Cloudflare still offers this method but only for use with the `Set-Cookie` header. This is because cookies will often contain date strings, which include commas. This can make parsing multiple values in a `Set-Cookie` header more difficult. Any attempts to use `Headers.getAll` with other header names will throw an error. A brief history `Headers.getAll` is available in this [GitHub issue](https://github.com/whatwg/fetch/issues/973).
+
+- Due to [RFC 6265](https://www.rfc-editor.org/rfc/rfc6265) prohibiting folding multiple `Set-Cookie` headers into a single header, the `Headers.append` method will allow you to set multiple `Set-Cookie` response headers instead of appending the value onto the existing header.
+
+```js
+const headers = new Headers();
+
+headers.append("Set-Cookie", "cookie1=value_for_cookie_1; Path=/; HttpOnly;");
+headers.append("Set-Cookie", "cookie2=value_for_cookie_2; Path=/; HttpOnly;");
+
+console.log(headers.getAll("Set-Cookie"));
+// Array(2) [ cookie1=value_for_cookie_1; Path=/; HttpOnly;, cookie2=value_for_cookie_2; Path=/; HttpOnly; ]
+```
+
+- In Cloudflare Workers, the `Headers.get` method returns a [`USVString`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) instead of a [`ByteString`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String), which is specified by the spec. For most scenarios, this should have no noticeable effect. To compare the differences between these two string classes, refer to this [Playground example](https://workers.cloudflare.com/playground#LYVwNgLglgDghgJwgegGYHsHALQBM4RwDcABAEbogB2+CAngLzbMutvvsCMALAJx-cAzAHZeANkG8AHAAZOU7t2EBWAEy9eqsXNWdOALg5HjbHv34jxk2fMUr1m7Z12cAsACgAwuioQApr7YACJQAM4w6KFQ0D76JBhYeATEJFRwwH4MAERQNH4AHgB0AFahWaSoUGAB6Zk5eUWlWR7evgEQ2AAqdDB+cXAwMGBQAMYEUD7IxXAAbnChIwiwEADUwOi44H4eHgURSCS4fqhw4BAkAN7uAJDzdFQj8X4QIwAWABQIfgCOIH6hEAAlJcbtdqucxucGCQsoBeDcAXHtZUHgkggCCoKSeAgkaFUPwAdxInQKEAAog8Nn4EO9AYUAiNKe9IYDkc8SPTKbgsVCSABlCBLKgAc0KqAQ6GAnleiG8R3ehQVaIx3JZoIZVFC6GqhTA6CF7yynVeYRIJrgJAAqryAGr8wVCkj46KvEjmyH6LIAGhIzLVPk12t1+sNxtCprD5oAQnR-Hbcg6nRAXW7sT5LZ0AGLYKQe70co5cgiq67XZDIEgACT8cCOCAjXxIoRAg0iflwJAg6EdmAA1iQfGA6I7nSRo7GBfHQt6yGj+yAEKCy6bgEM-BlfOM0yBQv9LTa48LQoUiaHUiSSMM8cOwGASDBBec4Ivy-jEFR466KLOk2FCqzzq81a1mGuIEpWQFUqE7wXDC+ZttgkJZHEcGFucAC+xbXF8EDzlQZ6EgASv8EQan4BpSn4Ix9pQ5xJn4JAAAatAGfgMa6NAdoBJBEeE-r0YBNaQR2XY7vRdFzhAMCzgyK6IGE-qFF6lwkAJwEkBhNxoe4aEeCYelGGYAiWBI0hyAoShqBoWg6HoLQ+P4gQhLxUQxFQcQJDg+CEKQaQZNkGSEF5cDlPEVQ1H5WRkLqZDNF49ntF0PR9K6gzDJCExUFMmpUDs7gXFkwBwLkAD66ybNUSH1EcjRlDp7j6Q1rCGRYogmTY5n2FZTguMwHhAA).
+
+## Cloudflare headers
+
+Cloudflare sets a number of its own custom headers on incoming requests and outgoing responses. While some may be used for its own tracking and bookkeeping, many of these can be useful to your own applications – or Workers – too.
+
+For a list of documented Cloudflare request headers, refer to [HTTP request headers](/fundamentals/reference/http-request-headers/).
+
+## Related resources
+
+* [Logging headers to console](/workers/examples/logging-headers/) - Review how to log headers in the console.
+* [HTTP request headers](/fundamentals/reference/http-request-headers/) - A list of specific headers Cloudflare adds.
diff --git a/test_files/source/cloudflare workers runtime api request.md b/test_files/source/cloudflare workers runtime api request.md
new file mode 100644
index 0000000..9d71626
--- /dev/null
+++ b/test_files/source/cloudflare workers runtime api request.md	
@@ -0,0 +1,417 @@
+---
+pcx_content_type: configuration
+title: Request
+meta:
+  description: Interface that represents an HTTP request.
+---
+
+# Request
+
+The [`Request`](https://developer.mozilla.org/en-US/docs/Web/API/Request/Request) interface represents an HTTP request and is part of the [Fetch API](/workers/runtime-apis/fetch/).
+
+## Background
+
+The most common way you will encounter a `Request` object is as a property of an incoming request:
+
+```js
+---
+highlight: [2]
+---
+export default {
+	async fetch(request, env, ctx) { 
+		return new Response('Hello World!');
+	},
+};
+```
+
+You may also want to construct a `Request` yourself when you need to modify a request object, because the incoming request parameter is immutable.
+
+```js
+export default {
+	async fetch(request, env, ctx) { 
+        const url = "https://example.com";
+        const modifiedRequest = new Request(url, request);
+		// ...
+	},
+};
+```
+
+The [`fetch() handler`](/workers/runtime-apis/handlers/fetch/) invokes the `Request` constructor. The [`RequestInit`](#options) and [`RequestInitCfProperties`](#the-cf-property-requestinitcfproperties) types defined below also describe the valid parameters that can be passed to the [`fetch() handler`](/workers/runtime-apis/handlers/fetch/).
+
+---
+
+## Constructor
+
+```js
+let request = new Request(input, options)
+```
+
+### Parameters
+
+{{<definitions>}}
+
+*   `input` {{<type>}}string | Request{{</type>}}
+
+    *   Either a string that contains a URL, or an existing `Request` object.
+
+*   `options` {{<type-link href="#options">}}options{{</type-link>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Optional options object that contains settings to apply to the `Request`.
+
+{{</definitions>}}
+
+#### `options`
+
+An object containing properties that you want to apply to the request.
+
+{{<definitions>}}
+
+*   `cf` {{<type-link href="#the-cf-property-requestinitcfproperties">}}RequestInitCfProperties{{</type-link>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Cloudflare-specific properties that can be set on the `Request` that control how Cloudflare’s global network handles the request.
+
+*   `method` {{<type>}}string{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   The HTTP request method. The default is `GET`. In Workers, all [HTTP request methods](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods) are supported, except for [`CONNECT`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/CONNECT).
+
+*   `headers` {{<type>}}Headers{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   A [`Headers` object](https://developer.mozilla.org/en-US/docs/Web/API/Headers).
+
+*   `body` {{<type>}}string | ReadableStream | FormData | URLSearchParams{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   The request body, if any.
+    *   Note that a request using the GET or HEAD method cannot have a body.
+
+*   `redirect` {{<type>}}string{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   The redirect mode to use: `follow`, `error`, or `manual`. The default  for a new `Request` object is `follow`. Note, however, that the incoming `Request` property of a `FetchEvent` will have redirect mode `manual`.
+
+{{</definitions>}}
+
+#### The `cf` property (`RequestInitCfProperties`)
+
+An object containing Cloudflare-specific properties that can be set on the `Request` object. For example:
+
+```js
+// Disable ScrapeShield for this request.
+fetch(event.request, { cf: { scrapeShield: false } })
+```
+
+Invalid or incorrectly-named keys in the `cf` object will be silently ignored. Consider using TypeScript and [`@cloudflare/workers-types`](https://github.com/cloudflare/workers-types) to ensure proper use of the `cf` object.
+
+{{<definitions>}}
+
+*   `apps` {{<type>}}boolean{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Whether [Cloudflare Apps](https://www.cloudflare.com/apps/) should be enabled for this request. Defaults to `true`.
+
+*   `cacheEverything` {{<type>}}boolean{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *    Treats all content as static and caches all [file types](/cache/concepts/default-cache-behavior#default-cached-file-extensions) beyond the Cloudflare default cached content. Respects cache headers from the origin web server. This is equivalent to setting the Page Rule [**Cache Level** (to **Cache Everything**)](/rules/page-rules/reference/settings/). Defaults to `false`.
+        This option applies to `GET` and `HEAD` request methods only.
+
+*   `cacheKey` {{<type>}}string{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   A request’s cache key is what determines if two requests are the same for caching purposes. If a request has the same cache key as some previous request, then Cloudflare can serve the same cached response for both.
+
+*   `cacheTags` {{<type>}}Array\<string\>{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   This option appends additional [**Cache-Tag**](/cache/how-to/purge-cache/purge-by-tags/) headers to the response from the origin server. This allows for purges of cached content based on tags provided by the Worker, without modifications to the origin server. This is performed using the [**Purge by Tag**](/cache/how-to/purge-cache/purge-by-tags/#purge-using-cache-tags) feature, which is currently only available to Enterprise zones. If this option is used in a non-Enterprise zone, the additional headers will not be appended.
+
+*   `cacheTtl` {{<type>}}number{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   This option forces Cloudflare to cache the response for this request, regardless of what headers are seen on the response. This is equivalent to setting two Page Rules: [**Edge Cache TTL**](/cache/how-to/edge-browser-cache-ttl/) and [**Cache Level** (to **Cache Everything**)](/rules/page-rules/reference/settings/). The value must be zero or a positive number. A value of `0` indicates that the cache asset expires immediately. This option applies to `GET` and `HEAD` request methods only.
+
+*   `cacheTtlByStatus` {{<type>}}{ \[key: string]: number }{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   This option is a version of the `cacheTtl` feature which chooses a TTL based on the response’s status code. If the response to this request has a status code that matches, Cloudflare will cache for the instructed time and override cache instructives sent by the origin. For example: `{ "200-299": 86400, "404": 1, "500-599": 0 }`. The value can be any integer, including zero and negative integers. A value of `0` indicates that the cache asset expires immediately. Any negative value instructs Cloudflare not to cache at all. This option applies to `GET` and `HEAD` request methods only.
+
+*   `image` {{<type>}}Object | null{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Enables [Image Resizing](/images/transform-images/) for this request. The possible values are described in [Transform images via Workers](/images/transform-images/transform-via-workers/) documentation.
+
+*   `minify` {{<type>}}{ javascript?: boolean; css?: boolean; html?: boolean; }{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Enables or disables [AutoMinify](https://www.cloudflare.com/website-optimization/) for various file types. For example: `{ javascript: true, css: true, html: false }`.
+
+*   `mirage` {{<type>}}boolean{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Whether [Mirage](https://www.cloudflare.com/website-optimization/mirage/) should be enabled for this request, if otherwise configured for this zone. Defaults to `true`.
+
+*   `polish` {{<type>}}string{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Sets [Polish](https://blog.cloudflare.com/introducing-polish-automatic-image-optimizati/) mode. The possible values are `lossy`, `lossless` or `off`.
+
+*   `resolveOverride` {{<type>}}string{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Directs the request to an alternate origin server by overriding the DNS lookup. The value of `resolveOverride` specifies an alternate hostname which will be used when determining the origin IP address, instead of using the hostname specified in the URL. The `Host` header of the request will still match what is in the URL. Thus, `resolveOverride` allows a request to be sent to a different server than the URL / `Host` header specifies. However, `resolveOverride` will only take effect if both the URL host and the host specified by `resolveOverride` are within your zone. If either specifies a host from a different zone / domain, then the option will be ignored for security reasons. If you need to direct a request to a host outside your zone (while keeping the `Host` header pointing within your zone), first create a CNAME record within your zone pointing to the outside host, and then set `resolveOverride` to point at the CNAME record. Note that, for security reasons, it is not possible to set the `Host` header to specify a host outside of your zone unless the request is actually being sent to that host.
+
+*   `scrapeShield` {{<type>}}boolean{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Whether [ScrapeShield](https://blog.cloudflare.com/introducing-scrapeshield-discover-defend-dete/) should be enabled for this request, if otherwise configured for this zone. Defaults to `true`.
+
+*   `webp` {{<type>}}boolean{{</type>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+    *   Enables or disables [WebP](https://blog.cloudflare.com/a-very-webp-new-year-from-cloudflare/) image format in [Polish](/images/polish/).
+
+{{</definitions>}}
+
+---
+
+## Properties
+
+All properties of an incoming `Request` object (that is, `event.request`) are read only. To modify a request, create a new `Request` object and pass the options to modify to its [constructor](#constructor).
+
+{{<definitions>}}
+
+*   `body` {{<type>}}ReadableStream{{</type>}} {{<prop-meta>}}read-only{{</prop-meta>}}
+
+    *   Stream of the body contents.
+
+*   `bodyUsed` {{<type>}}Boolean{{</type>}} {{<prop-meta>}}read-only{{</prop-meta>}}
+
+    *   Declares whether the body has been used in a response yet.
+
+*   `cf` {{<type-link href="#incomingrequestcfproperties">}}IncomingRequestCfProperties{{</type-link>}} {{<prop-meta>}}read-only{{</prop-meta>}}
+
+    *   An object containing properties about the incoming request provided by Cloudflare’s global network.
+
+*   `headers` {{<type>}}Headers{{</type>}} {{<prop-meta>}}read-only{{</prop-meta>}}
+
+    *   A [`Headers` object](https://developer.mozilla.org/en-US/docs/Web/API/Headers).
+
+    {{<Aside type="note">}}
+Note that, compared to browsers, Cloudflare Workers imposes very few restrictions on what headers you are allowed to send. For example, a browser will not allow you to set the `Cookie` header, since the browser is responsible for handling cookies itself. Workers, however, has no special understanding of cookies, and treats the `Cookie` header like any other header.
+    {{</Aside>}}
+
+    {{<Aside type="warning">}}
+If the response is a redirect and the redirect mode is set to `follow` (see below), then all headers will be forwarded to the redirect destination, even if the destination is a different hostname or domain. This includes sensitive headers like `Cookie`, `Authorization`, or any application-specific headers. If this is not the behavior you want, you should set redirect mode to `manual` and implement your own redirect policy. Note that redirect mode defaults to `manual` for requests that originated from the Worker's client, so this warning only applies to `fetch()`es made by a Worker that are not proxying the original request.
+    {{</Aside>}}
+
+*   `method` {{<type>}}string{{</type>}} {{<prop-meta>}}read-only{{</prop-meta>}}
+
+    *   Contains the request’s method, for example, `GET`, `POST`, etc.
+
+*   `redirect` {{<type>}}string{{</type>}} {{<prop-meta>}}read-only{{</prop-meta>}}
+
+    *   The redirect mode to use: `follow`, `error`, or `manual`. The `fetch` method will automatically follow redirects if the redirect mode is set to `follow`. If set to `manual`, the `3xx` redirect response will be returned to the caller as-is. The default for a new `Request` object is `follow`. Note, however, that the incoming `Request` property of a `FetchEvent` will have redirect mode `manual`.
+
+*   `url` {{<type>}}string{{</type>}} {{<prop-meta>}}read-only{{</prop-meta>}}
+
+    *   Contains the URL of the request.
+
+{{</definitions>}}
+
+### `IncomingRequestCfProperties`
+
+In addition to the properties on the standard [`Request`](https://developer.mozilla.org/en-US/docs/Web/API/Request) object, the `request.cf` object on an inbound `Request` contains information about the request provided by Cloudflare’s global network.
+
+All plans have access to:
+
+{{<definitions>}}
+
+*   `asn` {{<type>}}Number{{</type>}}
+
+    *   ASN of the incoming request, for example, `395747`.
+
+*   `asOrganization` {{<type>}}string{{</type>}}
+
+    *   The organization which owns the ASN of the incoming request, for example, `Google Cloud`.
+
+*   `botManagement` {{<type>}}Object | null{{</type>}}
+
+    *   Only set when using Cloudflare Bot Management. Object with the following properties: `score`, `verifiedBot`, `staticResource`, `ja3Hash`, and `detectionIds`. Refer to [Bot Management Variables](/bots/reference/bot-management-variables/) for more details.
+
+*   `clientAcceptEncoding` {{<type>}}string | null{{</type>}}
+
+    *   If Cloudflare replaces the value of the `Accept-Encoding` header, the original value is stored in the `clientAcceptEncoding` property, for example, `"gzip, deflate, br"`.
+
+*   `colo` {{<type>}}string{{</type>}}
+
+    *   The three-letter [`IATA`](https://en.wikipedia.org/wiki/IATA_airport_code) airport code of the data center that the request hit, for example, `"DFW"`.
+
+*   `country` {{<type>}}string | null{{</type>}}
+
+    *   Country of the incoming request. The two-letter country code in the request. This is the same value as that provided in the `CF-IPCountry` header, for example, `"US"`.
+
+*   `isEUCountry` {{<type>}}string | null{{</type>}}
+
+    *   If the country of the incoming request is in the EU, this will return `"1"`. Otherwise, this property will be omitted.
+
+*   `httpProtocol` {{<type>}}string{{</type>}}
+
+    *   HTTP Protocol, for example, `"HTTP/2"`.
+
+*   `requestPriority` {{<type>}}string | null{{</type>}}
+
+    *   The browser-requested prioritization information in the request object, for example, `"weight=192;exclusive=0;group=3;group-weight=127"`.
+
+*   `tlsCipher` {{<type>}}string{{</type>}}
+
+    *   The cipher for the connection to Cloudflare, for example, `"AEAD-AES128-GCM-SHA256"`.
+
+*   `tlsClientAuth` {{<type>}}Object | null{{</type>}}
+
+    *   Only set when using Cloudflare Access or API Shield (mTLS). Object with the following properties: `certFingerprintSHA1`, `certFingerprintSHA256`, `certIssuerDN`, `certIssuerDNLegacy`, `certIssuerDNRFC2253`, `certIssuerSKI`, `certIssuerSerial`, `certNotAfter`, `certNotBefore`, `certPresented`, `certRevoked`, `certSKI`, `certSerial`, `certSubjectDN`, `certSubjectDNLegacy`, `certSubjectDNRFC2253`, `certVerified`.
+
+*   `tlsClientHelloLength` {{<type>}}string{{</type>}}
+
+    *   The length of the client hello message sent in a [TLS handshake](https://www.cloudflare.com/learning/ssl/what-happens-in-a-tls-handshake/). For example, `"508"`. Specifically, the length of the bytestring of the client hello, after the hexidecimal bytes have been decoded.
+
+*   `tlsClientRandom` {{<type>}}string{{</type>}}
+
+    *   The value of the 32-byte random value provided by the client in a [TLS handshake](https://www.cloudflare.com/learning/ssl/what-happens-in-a-tls-handshake/). Refer to [RFC 8446](https://datatracker.ietf.org/doc/html/rfc8446#section-4.1.2) for more details.
+
+*   `tlsVersion` {{<type>}}string{{</type>}}
+
+    *   The TLS version of the connection to Cloudflare, for example, `TLSv1.3`.
+
+*   `city` {{<type>}}string | null{{</type>}}
+
+    *   City of the incoming request, for example, `"Austin"`.
+
+*   `continent` {{<type>}}string | null{{</type>}}
+
+    *   Continent of the incoming request, for example, `"NA"`.
+
+*   `latitude` {{<type>}}string | null{{</type>}}
+
+    *   Latitude of the incoming request, for example, `"30.27130"`.
+
+*   `longitude` {{<type>}}string | null{{</type>}}
+
+    *   Longitude of the incoming request, for example, `"-97.74260"`.
+
+*   `postalCode` {{<type>}}string | null{{</type>}}
+
+    *   Postal code of the incoming request, for example, `"78701"`.
+
+*   `metroCode` {{<type>}}string | null{{</type>}}
+
+    *   Metro code (DMA) of the incoming request, for example, `"635"`.
+
+*   `region` {{<type>}}string | null{{</type>}}
+
+    *   If known, the [ISO 3166-2](https://en.wikipedia.org/wiki/ISO_3166-2) name for the first level region associated with the IP address of the incoming request, for example, `"Texas"`.
+
+*   `regionCode` {{<type>}}string | null{{</type>}}
+
+    *   If known, the [ISO 3166-2](https://en.wikipedia.org/wiki/ISO_3166-2) code for the first-level region associated with the IP address of the incoming request, for example, `"TX"`.
+
+*   `timezone` {{<type>}}string{{</type>}}
+
+    *   Timezone of the incoming request, for example, `"America/Chicago"`.
+
+{{</definitions>}}
+
+{{<Aside type="warning">}}
+
+The `request.cf` object is not available in the Cloudflare Workers dashboard or Playground preview editor.
+
+{{</Aside>}}
+
+---
+
+## Methods
+
+### Instance methods
+
+These methods are only available on an instance of a `Request` object or through its prototype.
+
+{{<definitions>}}
+
+*   `clone()` : {{<type>}}Promise\<Request>{{</type>}}
+
+    *   Creates a copy of the `Request` object.
+
+*   `arrayBuffer()` : {{<type>}}Promise\<ArrayBuffer>{{</type>}}
+
+    *   Returns a promise that resolves with an [`ArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer) representation of the request body.
+
+*   `formData()` : {{<type>}}Promise\<FormData>{{</type>}}
+
+    *   Returns a promise that resolves with a [`FormData`](https://developer.mozilla.org/en-US/docs/Web/API/FormData) representation of the request body.
+
+*   `json()` : {{<type>}}Promise\<Object>{{</type>}}
+
+    *   Returns a promise that resolves with a JSON representation of the request body.
+
+*   `text()` : {{<type>}}Promise\<string>{{</type>}}
+
+    *   Returns a promise that resolves with a string (text) representation of the request body.
+
+{{</definitions>}}
+
+---
+
+## The `Request` context
+
+Each time a Worker is invoked by an incoming HTTP request, the [`fetch()` handler](/workers/runtime-apis/handlers/fetch) is called on your Worker. The `Request` context starts when the `fetch()` handler is called, and asynchronous tasks (such as making a subrequest using the [`fetch() API`](/workers/runtime-apis/fetch/)) can only be run inside the `Request` context:
+
+```js
+export default {
+	async fetch(request, env, ctx) {
+        // Request context starts here
+		return new Response('Hello World!');
+	},
+};
+```
+
+### When passing a promise to fetch event `.respondWith()`
+
+If you pass a Response promise to the fetch event `.respondWith()` method, the request context is active during any asynchronous tasks which run before the Response promise has settled. You can pass the event to an async handler, for example:
+
+```js
+addEventListener("fetch", event => {
+  event.respondWith(eventHandler(event))
+})
+
+// No request context available here
+
+async function eventHandler(event){
+  // Request context available here
+  return new Response("Hello, Workers!")
+}
+```
+
+### Errors when attempting to access an inactive `Request` context
+
+Any attempt to use APIs such as `fetch()` or access the `Request` context during script startup will throw an exception:
+
+```js
+const promise = fetch("https://example.com/") // Error
+async function eventHandler(event){..}
+```
+
+This code snippet will throw during script startup, and the `"fetch"` event listener will never be registered.
+
+***
+
+### Set the `Content-Length` header
+
+The `Content-Length` header will be automatically set by the runtime based on whatever the data source for the `Request` is. Any value manually set by user code in the `Headers` will be ignored. To have a `Content-Length` header with a specific value specified, the `body` of the `Request` must be either a `FixedLengthStream` or a fixed-length value just as a string or `TypedArray`.
+
+A `FixedLengthStream` is an identity `TransformStream` that permits only a fixed number of bytes to be written to it.
+
+```js
+  const { writable, readable } = new FixedLengthStream(11);
+
+  const enc = new TextEncoder();
+  const writer = writable.getWriter();
+  writer.write(enc.encode("hello world"));
+  writer.end();
+
+  const req = new Request('https://example.org', { method: 'POST', body: readable });
+```
+
+Using any other type of `ReadableStream` as the body of a request will result in Chunked-Encoding being used.
+
+---
+
+## Related resources
+
+* [Examples: Modify request property](/workers/examples/modify-request-property/)
+* [Examples: Accessing the `cf` object](/workers/examples/accessing-the-cloudflare-object/)
+* [Reference: `Response`](/workers/runtime-apis/response/)
+* Write your Worker code in [ES modules syntax](/workers/reference/migrate-to-module-workers/) for an optimized experience.
diff --git a/test_files/source/cloudflare workers runtime api response.md b/test_files/source/cloudflare workers runtime api response.md
new file mode 100644
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--- /dev/null
+++ b/test_files/source/cloudflare workers runtime api response.md	
@@ -0,0 +1,155 @@
+---
+pcx_content_type: configuration
+title: Response
+meta:
+  description: Interface that represents an HTTP response.
+---
+
+# Response
+
+The `Response` interface represents an HTTP response and is part of the Fetch API.
+
+---
+
+## Constructor
+
+```js
+let response = new Response(body, init);
+```
+
+### Parameters
+
+{{<definitions>}}
+
+- `body` {{<prop-meta>}}optional{{</prop-meta>}}
+
+  - An object that defines the body text for the response. Can be `null` or any one of the following types:
+
+    - {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/BufferSource">}}BufferSource{{</type-link>}}
+    - {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/FormData">}}FormData{{</type-link>}}
+    - {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream">}}ReadableStream{{</type-link>}}
+    - {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams">}}URLSearchParams{{</type-link>}}
+    - {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String">}}USVString{{</type-link>}}
+
+- `init` {{<prop-meta>}}optional{{</prop-meta>}}
+
+  - An `options` object that contains custom settings to apply to the response.
+
+{{</definitions>}}
+
+Valid options for the `options` object include: {{<definitions>}}
+
+- `status` {{<type>}}int{{</type>}}
+
+  - The status code for the response, such as `200`.
+
+- `statusText` {{<type>}}string{{</type>}}
+
+  - The status message associated with the status code, such as, `OK`.
+
+- `headers` {{<type-link href="/runtime-apis/request#parameters">}}Headers{{</type-link>}} | {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String">}}ByteString{{</type-link>}}
+  - Any headers to add to your response that are contained within a [`Headers`](/workers/runtime-apis/request/#parameters) object or object literal of [`ByteString`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) key-value pairs.
+
+{{</definitions>}}
+
+## Properties
+
+{{<definitions>}}
+
+- `response.body` {{<type-link href="/runtime-apis/streams">}}Readable Stream{{</type-link>}}
+  - A getter to get the body contents.
+- `response.bodyUsed` {{<type>}}boolean{{</type>}}
+  - A boolean indicating if the body was used in the response.
+- `response.encodeBody` {{<type>}}string{{</type>}}
+  - Workers have to compress data according to the `content-encoding` header when transmitting, to serve data that is already compressed, this property has to be set to `"manual"`, otherwise the default is `"automatic"`.
+- `response.headers` {{<type-link href="/runtime-apis/request#parameters">}}Headers{{</type-link>}}
+  - The headers for the response.
+- `response.ok` {{<type>}}boolean{{</type>}}
+  - A boolean indicating if the response was successful (status in the range `200`-`299`).
+- `response.redirected` {{<type>}}boolean{{</type>}}
+  - A boolean indicating if the response is the result of a redirect. If so, its URL list has more than one entry.
+- `response.status` {{<type>}}int{{</type>}}
+  - The status code of the response (for example, `200` to indicate success).
+- `response.statusText` {{<type>}}string{{</type>}}
+  - The status message corresponding to the status code (for example, `OK` for `200`).
+- `response.url` {{<type>}}string{{</type>}}
+  - The URL of the response. The value is the final URL obtained after any redirects.
+
+<!-- What type is this? WebSocket? -->
+
+- `response.webSocket`
+  - This is present in successful WebSocket handshake responses. For example, if a client sends a WebSocket upgrade request to an origin and a Worker intercepts the request and then forwards it to the origin and the origin replies with a successful WebSocket upgrade response, the Worker sees `response.webSocket`. This establishes a WebSocket connection proxied through a Worker. Note that you cannot intercept data flowing over a WebSocket connection.
+
+{{</definitions>}}
+
+## Methods
+
+### Instance methods
+
+{{<definitions>}}
+
+- `clone()` : {{<type-link href="#response">}}Response{{</type-link>}}
+
+  - Creates a clone of a [`Response`](#response) object.
+
+- `json()` : {{<type-link href="#response">}}Response{{</type-link>}}
+
+  - Creates a new response with a JSON-serialized payload.
+
+- `redirect()` : {{<type-link href="#response">}}Response{{</type-link>}}
+
+  - Creates a new response with a different URL.
+
+{{</definitions>}}
+
+### Additional instance methods
+
+`Response` implements the [`Body`](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#body) mixin of the [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API), and therefore `Response` instances additionally have the following methods available:
+
+{{<definitions>}}
+
+- {{<code>}}arrayBuffer(){{</code>}} : {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer">}}Promise\<ArrayBuffer>{{</type-link>}}
+
+  - Takes a [`Response`](#response) stream, reads it to completion, and returns a promise that resolves with an [`ArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer).
+
+- {{<code>}}formData(){{</code>}} : {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/FormData">}}Promise\<FormData>{{</type-link>}}
+
+  - Takes a [`Response`](#response) stream, reads it to completion, and returns a promise that resolves with a [`FormData`](https://developer.mozilla.org/en-US/docs/Web/API/FormData) object.
+
+- {{<code>}}json(){{</code>}} : {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/">}}Promise\<JSON>{{</type-link>}}
+
+  - Takes a [`Response`](#response) stream, reads it to completion, and returns a promise that resolves with the result of parsing the body text as [`JSON`](https://developer.mozilla.org/en-US/docs/Web/).
+
+- {{<code>}}text(){{</code>}} : {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String">}}Promise\<USVString>{{</type-link>}}
+
+  - Takes a [`Response`](#response) stream, reads it to completion, and returns a promise that resolves with a [`USVString`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) (text).
+
+{{</definitions>}}
+
+### Set the `Content-Length` header
+
+The `Content-Length` header will be automatically set by the runtime based on whatever the data source for the `Response` is. Any value manually set by user code in the `Headers` will be ignored. To have a `Content-Length` header with a specific value specified, the `body` of the `Response` must be either a `FixedLengthStream` or a fixed-length value just as a string or `TypedArray`.
+
+A `FixedLengthStream` is an identity `TransformStream` that permits only a fixed number of bytes to be written to it.
+
+```js
+  const { writable, readable } = new FixedLengthStream(11);
+
+  const enc = new TextEncoder();
+  const writer = writable.getWriter();
+  writer.write(enc.encode("hello world"));
+  writer.end();
+
+  return new Response(readable);
+```
+
+Using any other type of `ReadableStream` as the body of a response will result in chunked encoding being used.
+
+---
+
+## Related resources
+
+- [Examples: Modify response](/workers/examples/modify-response/)
+- [Examples: Conditional response](/workers/examples/conditional-response/)
+- [Reference: `Request`](/workers/runtime-apis/request/)
+- Write your Worker code in [ES modules syntax](/workers/reference/migrate-to-module-workers/) for an optimized experience.
diff --git a/test_files/source/cloudflare workers runtime api web-standards.md b/test_files/source/cloudflare workers runtime api web-standards.md
new file mode 100644
index 0000000..785d5a5
--- /dev/null
+++ b/test_files/source/cloudflare workers runtime api web-standards.md	
@@ -0,0 +1,201 @@
+---
+title: Web standards
+pcx_content_type: configuration
+meta:
+  title: JavaScript and web standards
+  description: Standardized APIs for use by Workers running on Cloudflare's global network.
+---
+
+# JavaScript and web standards
+
+The Workers runtime provides the following standardized APIs for use by Workers running on Cloudflare's global network.
+
+---
+
+## JavaScript standards
+
+Cloudflare Workers uses the V8 JavaScript engine from Google Chrome. The Workers runtime is updated at least once a week, to at least the version that is currently used by Chrome's stable release. This means you can safely use the latest JavaScript features, with no need for transpilers.
+
+All of the [standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference) supported by the current Google Chrome stable release are supported, with a few notable exceptions:
+
+- `eval()` is not allowed for security reasons.
+- `new Function` is not allowed for security reasons.
+- `Date.now()` returns the time of the last I/O; it does not advance during code execution.
+
+---
+
+## Web global APIs
+
+The following methods are available per the [Worker Global Scope](https://developer.mozilla.org/en-US/docs/Web/API/WorkerGlobalScope):
+
+### Base64 utility methods
+
+{{<definitions>}}
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/atob">}}atob(){{</type-link>}}
+
+  - Decodes a string of data which has been encoded using base-64 encoding.
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/btoa">}}btoa(){{</type-link>}}
+
+  - Creates a base-64 encoded ASCII string from a string of binary data.
+
+{{</definitions>}}
+
+### Timers
+
+{{<definitions>}}
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/setInterval">}}setInterval(){{</type-link>}}
+
+  - Schedules a function to execute every time a given number of milliseconds elapses.
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/clearInterval">}}clearInterval(){{</type-link>}}
+
+  - Cancels the repeated execution set using [`setInterval()`](https://developer.mozilla.org/en-US/docs/Web/API/setInterval).
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/setTimeout">}}setTimeout(){{</type-link>}}
+
+  - Schedules a function to execute in a given amount of time.
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/clearTimeout">}}clearTimeout(){{</type-link>}}
+
+  - Cancels the delayed execution set using [`setTimeout()`](https://developer.mozilla.org/en-US/docs/Web/API/setTimeout).
+
+{{</definitions>}}
+
+{{<Aside type="note">}}
+
+Timers are only available inside of [the Request Context](/workers/runtime-apis/request/#the-request-context).
+
+{{</Aside>}}
+
+### `performance.timeOrigin` and `performance.now()`
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/Performance/timeOrigin">}}performance.timeOrigin{{</type-link>}}
+
+  - Returns the high resolution time origin. Workers uses the UNIX epoch as the time origin, meaning that `performance.timeOrigin` will always return `0`.
+
+- {{<type-link href="">}}performance.now(){{</type-link>}}
+
+  - Returns a `DOMHighResTimeStamp` representing the number of milliseconds elapsed since `performance.timeOrigin`. Note that Workers intentionally reduces the precision of `performance.now()` such that it returns the time of the last I/O and does not advance during code execution. Effectively, because of this, and because `performance.timeOrigin` is always, `0`, `performance.now()` will always equal `Date.now()`, yielding a consistent view of the passage of time within a Worker.
+
+### `EventTarget` and `Event`
+
+The [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget) and [`Event`](https://developer.mozilla.org/en-US/docs/Web/API/Event) API allow objects to publish and subscribe to events.
+
+### `AbortController` and `AbortSignal`
+
+The [`AbortController`](https://developer.mozilla.org/en-US/docs/Web/API/AbortController) and [`AbortSignal`](https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal) APIs provide a common model for canceling asynchronous operations.
+
+### Fetch global
+
+{{<definitions>}}
+
+- {{<type-link href="https://developer.mozilla.org/en-US/docs/Web/API/fetch">}}fetch(){{</type-link>}}
+
+  - Starts the process of fetching a resource from the network. Refer to [Fetch API](/workers/runtime-apis/fetch/).
+
+{{</definitions>}}
+
+{{<Aside type="note">}}
+
+The Fetch API is only available inside of [the Request Context](/workers/runtime-apis/request/#the-request-context).
+
+{{</Aside>}}
+
+---
+
+## Encoding API
+
+Both `TextEncoder` and `TextDecoder` support UTF-8 encoding/decoding.
+
+[Refer to the MDN documentation for more information](https://developer.mozilla.org/en-US/docs/Web/API/Encoding_API).
+
+The [`TextEncoderStream`](https://developer.mozilla.org/en-US/docs/Web/API/TextEncoderStream) and [`TextDecoderStream`](https://developer.mozilla.org/en-US/docs/Web/API/TextDecoderStream) classes are also available.
+
+---
+
+## URL API
+
+The URL API supports URLs conforming to HTTP and HTTPS schemes.
+
+[Refer to the MDN documentation for more information](https://developer.mozilla.org/en-US/docs/Web/API/URL)
+
+{{<Aside type="note">}}
+
+The default URL class behavior differs from the URL Spec documented above.
+
+A new spec-compliant implementation of the URL class can be enabled using the `url_standard` [compatibility flag](/workers/configuration/compatibility-dates/#compatibility-flags).
+
+{{</Aside>}}
+
+---
+
+## Compression Streams
+
+The `CompressionStream` and `DecompressionStream` classes support the deflate, deflate-raw and gzip compression methods.
+
+[Refer to the MDN documentation for more information](https://developer.mozilla.org/en-US/docs/Web/API/Compression_Streams_API)
+
+---
+
+## URLPattern API
+
+The `URLPattern` API provides a mechanism for matching URLs based on a convenient pattern syntax.
+
+[Refer to the MDN documentation for more information](https://developer.mozilla.org/en-US/docs/Web/API/URLPattern).
+
+---
+
+## `Intl`
+
+The `Intl` API allows you to format dates, times, numbers, and more to the format that is used by a provided locale (language and region).
+
+[Refer to the MDN documentation for more information](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl).
+
+---
+
+## `navigator.userAgent`
+
+When the [`global_navigator`](/workers/configuration/compatibility-dates/#global-navigator) compatibility flag is set, the [`navigator.userAgent`](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/userAgent) property is available with the value `'Cloudflare-Workers'`. This can be used, for example, to reliably determine that code is running within the Workers environment.
+
+## Unhandled promise rejections
+
+The [`unhandledrejection`](https://developer.mozilla.org/en-US/docs/Web/API/Window/unhandledrejection_event) event is emitted by the global scope when a JavaScript promise is rejected without a rejection handler attached.
+
+The [`rejectionhandled`](https://developer.mozilla.org/en-US/docs/Web/API/Window/rejectionhandled_event) event is emitted by the global scope when a JavaScript promise rejection is handled late (after a rejection handler is attached to the promise after an `unhandledrejection` event has already been emitted).
+
+```js
+---
+header: worker.js
+---
+addEventListener('unhandledrejection', (event) => {
+  console.log(event.promise);  // The promise that was rejected.
+  console.log(event.reason);  // The value or Error with which the promise was rejected.
+});
+
+addEventListener('rejectionhandled', (event) => {
+  console.log(event.promise);  // The promise that was rejected.
+  console.log(event.reason);  // The value or Error with which the promise was rejected.
+});
+```
+
+---
+
+## `navigator.sendBeacon(url[, data])`
+
+When the [`global_navigator`](/workers/configuration/compatibility-dates/#global-navigator) compatibility flag is set, the [`navigator.sendBeacon(...)`](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/sendBeacon) API is available to send an HTTP `POST` request containing a small amount of data to a web server. This API is intended as a means of transmitting analytics or diagnostics information asynchronously on a best-effort basis.
+
+For example, you can replace:
+
+```js
+const promise = fetch('https://example.com', { method: 'POST', body: 'hello world' });
+ctx.waitUntil(promise);
+```
+
+with `navigator.sendBeacon(...)`:
+
+```js
+navigator.sendBeacon('https://example.com', 'hello world');
+```
diff --git a/test_files/source/cloudflare workers runtime api websockets.md b/test_files/source/cloudflare workers runtime api websockets.md
new file mode 100644
index 0000000..acc18cb
--- /dev/null
+++ b/test_files/source/cloudflare workers runtime api websockets.md	
@@ -0,0 +1,148 @@
+---
+pcx_content_type: configuration
+title: WebSockets
+meta:
+  description: Communicate in real time with your Cloudflare Workers.
+---
+
+# WebSockets
+
+## Background
+
+WebSockets allow you to communicate in real time with your Cloudflare Workers serverless functions. For a complete example, refer to [Using the WebSockets API](/workers/examples/websockets/).
+
+{{<Aside type="note">}}
+
+If your application needs to coordinate among multiple WebSocket connections, such as a chat room or game match, you will need clients to send messages to a single-point-of-coordination. Durable Objects provide a single-point-of-coordination for Cloudflare Workers, and are often used in parallel with WebSockets to persist state over multiple clients and connections. In this case, refer to [Durable Objects](/durable-objects/) to get started, and prefer using the Durable Objects' extended [WebSockets API](/durable-objects/api/websockets/).
+
+{{</Aside>}}
+
+## Constructor
+
+```js
+// { 0: <WebSocket>, 1: <WebSocket> }
+let websocketPair = new WebSocketPair();
+```
+
+The WebSocketPair returned from this constructor is an Object, with two WebSockets at keys `0` and `1`.
+
+These WebSockets are commonly referred to as `client` and `server`. The below example combines `Object.values` and ES6 destructuring to retrieve the WebSockets as `client` and `server`:
+
+```js
+let [client, server] = Object.values(new WebSocketPair());
+```
+
+## Methods
+
+### accept
+
+{{<definitions>}}
+
+- {{<code>}}accept(){{</code>}}
+
+  - Accepts the WebSocket connection and begins terminating requests for the WebSocket on Cloudflare's global network. This effectively enables the Workers runtime to begin responding to and handling WebSocket requests.
+
+{{</definitions>}}
+
+### addEventListener
+
+{{<definitions>}}
+
+- {{<code>}}addEventListener(event{{<param-type>}}WebSocketEvent{{</param-type>}}, callbackFunction{{<param-type>}}Function{{</param-type>}}){{</code>}}
+
+  - Add callback functions to be executed when an event has occurred on the WebSocket.
+
+{{</definitions>}}
+
+#### Parameters
+
+{{<definitions>}}
+
+- `event` {{<type-link href="#events">}}WebSocketEvent{{</type-link>}}
+
+  - The WebSocket event (refer to [Events](/workers/runtime-apis/websockets/#events)) to listen to.
+
+- {{<code>}}callbackFunction(message{{<type-link href="#message">}}Message{{</type-link>}}){{</code>}} {{<type>}}Function{{</type>}}
+
+  - A function to be called when the WebSocket responds to a specific event.
+
+{{</definitions>}}
+
+### close
+
+{{<definitions>}}
+
+- {{<code>}}close(code{{<param-type>}}number{{</param-type>}}, reason{{<param-type>}}string{{</param-type>}}){{</code>}}
+
+  - Close the WebSocket connection.
+
+{{</definitions>}}
+
+#### Parameters
+
+{{<definitions>}}
+
+- {{<code>}}code{{<param-type>}}integer{{</param-type>}}{{</code>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+  - An integer indicating the close code sent by the server. This should match an option from the [list of status codes](https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent#status_codes) provided by the WebSocket spec.
+
+- {{<code>}}reason{{<param-type>}}string{{</param-type>}}{{</code>}} {{<prop-meta>}}optional{{</prop-meta>}}
+
+  - A human-readable string indicating why the WebSocket connection was closed.
+
+{{</definitions>}}
+
+### send
+
+{{<definitions>}}
+
+- {{<code>}}send(message{{<param-type>}}string{{</param-type>}} | {{<param-type>}}ArrayBuffer{{</param-type>}} | {{<param-type>}}ArrayBufferView{{</param-type>}}){{</code>}}
+
+  - Send a message to the other WebSocket in this WebSocket pair.
+
+{{</definitions>}}
+
+#### Parameters
+
+{{<definitions>}}
+
+- {{<code>}}message{{<param-type>}}string{{</param-type>}}{{</code>}}
+
+  - The message to send down the WebSocket connection to the corresponding client. This should be a string or something coercible into a string; for example, strings and numbers will be simply cast into strings, but objects and arrays should be cast to JSON strings using <code>JSON.stringify</code>, and parsed in the client.
+
+{{</definitions>}}
+
+---
+
+## Events
+
+{{<definitions>}}
+
+- {{<code>}}close{{</code>}}
+  - An event indicating the WebSocket has closed.
+
+- {{<code>}}error{{</code>}}
+  - An event indicating there was an error with the WebSocket.
+
+- {{<code>}}message{{</code>}}
+  - An event indicating a new message received from the client, including the data passed by the client.
+
+{{</definitions>}}
+
+## Types
+
+### Message
+
+{{<definitions>}}
+
+- `data` {{<type>}}any{{</type>}} - The data passed back from the other WebSocket in your pair.
+- `type` {{<type>}}string{{</type>}} - Defaults to `message`.
+
+{{</definitions>}}
+
+---
+
+## Related resources
+
+- [Mozilla Developer Network's (MDN) documentation on the WebSocket class](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket)
+- [Our WebSocket template for building applications on Workers using WebSockets](https://github.com/cloudflare/websocket-template)
diff --git a/test_files/source/dart-3-migration.md b/test_files/source/dart-3-migration.md
new file mode 100644
index 0000000..650e227
--- /dev/null
+++ b/test_files/source/dart-3-migration.md
@@ -0,0 +1,627 @@
+---
+title: Dart 3 migration guide
+description: How to migrate existing Dart code to be compatible with Dart 3.
+---
+
+Dart 3 is a major release that introduces new core capabilities to Dart: 
+[records][], [patterns][], and [class modifiers][].
+
+Alongside these new capabilities, Dart 3 contains a number of changes
+that may break existing code. 
+
+This guide will help you resolve any migration issues you might encounter
+after [upgrading to Dart 3](/get-dart).
+
+## Introduction
+
+### Unversioned vs versioned changes
+
+The potentially breaking changes listed below fall into one of two categories:
+
+* **Unversioned changes**: These changes affect any Dart code
+  after upgrading to a Dart 3.0 SDK or later. 
+  There is no way to "turn off" these changes.
+
+* **Versioned changes**: These changes only apply when the package or app's
+  language version is set to >= Dart 3.0. 
+  The [language version](/guides/language/evolution#language-version-numbers)
+  is derived from the `sdk` lower-constraint in the
+  [`pubspec.yaml` file](/guides/packages#creating-a-pubspec). 
+  An SDK constraint like this does *not* apply the Dart 3 versioned changes:
+
+  ```yaml
+  environment:
+    sdk: '>=2.14.0 <3.0.0'
+  ```
+  
+  But an SDK constraint like this does:
+
+  ```yaml
+  environment:
+    sdk: '>=3.0.0 <4.0.0'
+  ```
+
+To use the new Dart 3 features you have to
+update the language version to 3.0. 
+This gets you the Dart 3 versioned changes at the same time.
+
+### Dart 3 backwards compatibility
+
+Many packages and apps that used null safety with Dart 2.12 or
+later are likely backwards compatible with Dart 3. 
+This is possible for any package where 
+the lower bound of the SDK constraint is 2.12.0 or higher. 
+
+[Dart's pub tool](/guides/packages) allows resolution even when
+the upper bound is limited to versions below 3.0.0. 
+For example, a package with the following constraint
+will be allowed to resolve with a Dart 3.x SDK, 
+as pub will re-interpret the upper-constraint `<3.0.0` as `<4.0.0`
+when the lower constraint is `2.12` or higher:
+
+```yaml
+environment:
+  sdk: '>=2.14.0 <3.0.0'           # This is interpreted as '>=2.14.0 <4.0.0'
+```
+
+This allows developers to use Dart 3 sound null safety with packages
+that already support 2.12 null safety
+without needing a second migration, unless 
+the code is affected by any other Dart 3 changes.
+
+### Testing for impact
+
+To understand if your source code is impacted by any Dart 3 changes, 
+use these steps:
+
+```console
+$ dart --version    # Make sure this reports 3.0.0 or higher.
+$ dart pub get      # This should resolve without issues.
+$ dart analyze      # This should pass without errors.
+```
+
+If the `pub get` step fails, try to upgrade your dependencies
+to see if more recent versions might support Dart 3:
+
+```console
+$ dart pub upgrade
+$ dart analyze      # This should pass without errors.
+```
+
+Or, if needed, also include [major versions][] upgrades:
+
+```console
+$ dart pub upgrade --major-versions
+$ dart analyze      # This should pass without errors.
+```
+
+[major versions]: /tools/pub/cmd/pub-upgrade#major-versions
+
+## Dart 3 language changes
+
+### 100% sound null safety
+
+Dart 2.12 introduced null safety more than two years ago. 
+In Dart 2.12, users needed to enable null safety [with a pubspec setting][].
+In Dart 3, null safety is built in; you cannot turn it off.
+
+[with a pubspec setting]: /null-safety#enable-null-safety
+
+#### Scope
+
+This is an [*unversioned* change](#unversioned-vs-versioned-changes), 
+that applies to all Dart 3 code.
+
+#### Symptom
+
+Packages developed without null safety support will cause issues
+when resolving dependencies with `pub get`:
+
+```console
+$ dart pub get
+
+Because pkg1 doesn't support null safety, version solving failed.
+The lower bound of "sdk: '>=2.9.0 <3.0.0'" must be 2.12.0 or higher to enable null safety.
+```
+
+Libraries that opt out of null safety with [language version comments][]
+that select any language version below `2.12` will
+cause analysis or compilation errors:
+
+```console
+$ dart analyze .
+Analyzing ....                         0.6s
+
+  error • lib/pkg1.dart:1:1 • The language version must be >=2.12.0. 
+  Try removing the language version override and migrating the code.
+  • illegal_language_version_override
+```
+
+```console
+$ dart run bin/my_app.dart
+../pkg1/lib/pkg1.dart:1:1: Error: Library doesn't support null safety.
+// @dart=2.9
+^^^^^^^^^^^^
+```
+
+[language version comments]: /guides/language/evolution#per-library-language-version-selection
+
+#### Migration
+
+Before beginning any migration to Dart 3, 
+ensure your app or package has been 100% migrated to enable null safety. 
+This requires a Dart `2.19` SDK, not a Dart 3 SDK. 
+To learn how to first migrate your app or package to support null safety,
+check out the [null safety migration guide][].
+
+[null safety migration guide]: /null-safety/migration-guide
+
+### Colon-syntax for default values
+
+For historical reasons, named optional parameters could
+specify their default value using either `:` or `=`. 
+In Dart 3, only the `=` syntax is allowed.
+
+#### Scope
+
+This is a [*versioned* change](#unversioned-vs-versioned-changes), 
+that only applies to language version 3.0 or later.
+
+#### Symptom
+
+Dart analysis produces errors like:
+
+```plaintext
+line 2 • Using a colon as a separator before a default value is no longer supported.
+```
+
+#### Migration
+
+Change from using colons:
+
+```dart
+int someInt({int x: 0}) => x;
+```
+
+To using equals:
+
+```dart
+int someInt({int x = 0}) => x;
+```
+
+This migration can be made manually, or automated with `dart fix`:
+
+```console
+$ dart fix --apply --code=obsolete_colon_for_default_value
+```
+
+### `mixin`
+
+Pre-Dart 3, any `class` could be used as a `mixin`, as long as
+it had no declared constructors and no superclass other than `Object`.
+
+In Dart 3, classes declared in libraries at language version 3.0 or later
+can't be used as mixins unless marked `mixin`.
+This restriction applies to code in any library
+attempting to use the class as a mixin, 
+regardless of the latter library's language version.
+
+#### Scope
+
+This is a [*versioned* change](#unversioned-vs-versioned-changes), 
+that only applies to language version 3.0 or later.
+
+#### Symptom
+
+An analysis error like:
+
+```plaintext
+Mixin can only be applied to class.
+```
+
+The analyzer produces this diagnostic when a class that is neither a
+`mixin class` nor a `mixin` is used in a `with` clause.
+
+#### Migration
+
+Determine if the class is intended to be used as a mixin.
+
+If the class defines an interface, consider using `implements`.
+
+### `switch`
+
+Dart 3.0 interprets [switch](/language/branches#switch) cases
+as [patterns][] instead of constant expressions. 
+
+#### Scope
+
+This is a [*versioned* change](#unversioned-vs-versioned-changes), 
+that only applies to language version 3.0 or later.
+
+#### Symptom
+
+Most constant expressions found in switch cases are valid patterns
+with the same meaning (named constants, literals, etc.).
+These will behave the same and no symptoms will arise.
+
+The few constant expressions that aren't valid patterns
+will trigger the [`invalid_case_patterns` lint][].
+
+[`invalid_case_patterns` lint]: /tools/linter-rules/invalid_case_patterns
+
+#### Migration
+
+You can revert back to the original behavior by prefixing
+the case pattern with `const`, so it's no longer interpreted as a pattern:
+
+```dart
+case const [1, 2]:
+case const {'k': 'v'}:
+case const {1, 2}:
+case const Point(1, 2):
+```
+
+You can run a quick fix for this breaking change, 
+by using `dart fix` or from your IDE.
+
+### `continue`
+
+Dart 3 reports a compile-time error if a continue statement targets a label
+that is not a loop (`for`, `do`, and `while` statements) or a switch member.
+
+#### Scope
+
+This is a [*versioned* change](#unversioned-vs-versioned-changes), 
+that only applies to language version 3.0 or later.
+
+#### Symptom
+
+You will see an error like:
+
+```plaintext
+The label used in a 'continue' statement must be defined on either a loop or a switch member.
+```
+
+#### Migration
+
+If changing behavior is acceptable, 
+change the `continue` to target a valid labeled statement,
+which must be attached to a `for`, `do` or `while` statement.
+
+If you want to preserve behavior, change the
+`continue` statement to a `break` statement.
+In previous versions of Dart, a `continue` statement 
+that wasn't targeted at a loop or a switch member 
+behaved like `break`.
+
+## Dart 3 core library changes
+
+### APIs removed
+
+**Breaking change [#49529][]**: The core libraries have been cleaned up
+to remove APIs that have been deprecated for several years. 
+The following APIs no longer exist in the Dart core libraries.
+
+[#49529]: https://github.com/dart-lang/sdk/issues/49529
+
+#### Scope
+
+This is an [*unversioned* change](#unversioned-vs-versioned-changes), 
+that applies to all Dart 3 code.
+
+#### `dart:core`
+
+- Removed the deprecated `List` constructor, as it wasn't null safe.
+  Use list literals (e.g. `[]` for an empty list or `<int>[]` for an empty
+  typed list) or [`List.filled`][]. This only impacts non-null safe code,
+  as null safe code already couldn't use this constructor.
+- Removed the deprecated `onError` argument on [`int.parse`][], [`double.parse`][],
+  and [`num.parse`][]. Use the [`tryParse`][] method instead.
+- Removed the deprecated [`proxy`][] and [`Provisional`][] annotations.
+  The original `proxy` annotation has no effect in Dart 2,
+  and the `Provisional` type and [`provisional`][] constant
+  were only used internally during the Dart 2.0 development process.
+- Removed the deprecated [`Deprecated.expires`][] getter.
+  Use [`Deprecated.message`][] instead.
+- Removed the deprecated [`CastError`][] error.
+  Use [`TypeError`][] instead.
+- Removed the deprecated [`FallThroughError`][] error. The kind of
+  fall-through previously throwing this error was made a compile-time
+  error in Dart 2.0.
+- Removed the deprecated [`NullThrownError`][] error. This error is never
+  thrown from null safe code.
+- Removed the deprecated [`AbstractClassInstantiationError`][] error. It was made
+  a compile-time error to call the constructor of an abstract class in Dart 2.0.
+- Removed the deprecated [`CyclicInitializationError`]. Cyclic dependencies are
+  no longer detected at runtime in null safe code. Such code will fail in other
+  ways instead, possibly with a StackOverflowError.
+- Removed the deprecated [`NoSuchMethodError`][] default constructor.
+  Use the [`NoSuchMethodError.withInvocation`][] named constructor instead.
+- Removed the deprecated [`BidirectionalIterator`][] class.
+  Existing bidirectional iterators can still work, they just don't have
+  a shared supertype locking them to a specific name for moving backwards.
+
+[`List.filled`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/List/List.filled.html
+[`int.parse`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/int/parse.html
+[`double.parse`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/double/parse.html
+[`num.parse`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/num/parse.html
+[`tryParse`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/num/tryParse.html
+[`Deprecated.expires`]: {{site.dart-api}}/stable/2.19.6/dart-core/Deprecated/expires.html
+[`Deprecated.message`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/Deprecated/message.html
+[`AbstractClassInstantiationError`]: {{site.dart-api}}/stable/2.19.6/dart-core/AbstractClassInstantiationError-class.html
+[`CastError`]: {{site.dart-api}}/stable/2.19.6/dart-core/CastError-class.html
+[`FallThroughError`]: {{site.dart-api}}/stable/2.19.6/dart-core/FallThroughError-class.html
+[`NoSuchMethodError`]: {{site.dart-api}}/stable/2.19.6/dart-core/NoSuchMethodError/NoSuchMethodError.html
+[`NoSuchMethodError.withInvocation`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/NoSuchMethodError/NoSuchMethodError.withInvocation.html
+[`CyclicInitializationError`]: {{site.dart-api}}/stable/2.19.6/dart-core/CyclicInitializationError-class.html
+[`Provisional`]: {{site.dart-api}}/stable/2.19.6/dart-core/Provisional-class.html
+[`provisional`]: {{site.dart-api}}/stable/2.19.6/dart-core/provisional-constant.html
+[`proxy`]: {{site.dart-api}}/stable/2.19.6/dart-core/proxy-constant.html
+[`CastError`]: {{site.dart-api}}/stable/2.19.6/dart-core/CastError-class.html
+[`TypeError`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-core/TypeError-class.html
+[`FallThroughError`]: {{site.dart-api}}/stable/2.19.6/dart-core/FallThroughError-class.html
+[`NullThrownError`]: {{site.dart-api}}/stable/2.19.6/dart-core/NullThrownError-class.html
+[`AbstractClassInstantiationError`]: {{site.dart-api}}/stable/2.19.6/dart-core/AbstractClassInstantiationError-class.html
+[`CyclicInitializationError`]: {{site.dart-api}}/stable/2.19.6/dart-core/CyclicInitializationError-class.html
+[`BidirectionalIterator`]: {{site.dart-api}}/stable/2.19.6/dart-core/BidirectionalIterator-class.html
+
+#### `dart:async`
+
+- Removed the deprecated [`DeferredLibrary`][] class.
+  Use the [`deferred as`][] import syntax instead.
+
+[`DeferredLibrary`]: {{site.dart-api}}/stable/2.19.6/dart-async/DeferredLibrary-class.html
+[`deferred as`]: /language/libraries#lazily-loading-a-library
+
+#### `dart:developer`
+
+- Removed the deprecated [`MAX_USER_TAGS`][] constant.
+  Use [`maxUserTags`][] instead.
+- Removed the deprecated [`Metrics`][], [`Metric`][], [`Counter`][],
+  and [`Gauge`][] classes as they have been broken since Dart 2.0.
+
+[`MAX_USER_TAGS`]: {{site.dart-api}}/stable/2.19.6/dart-developer/UserTag/MAX_USER_TAGS-constant.html
+[`maxUserTags`]: {{site.dart-api}}/{{site.sdkInfo.channel}}/dart-developer/UserTag/maxUserTags-constant.html
+[`Metrics`]: {{site.dart-api}}/stable/2.19.6/dart-developer/Metrics-class.html
+[`Metric`]: {{site.dart-api}}/stable/2.19.6/dart-developer/Metric-class.html
+[`Counter`]: {{site.dart-api}}/stable/2.19.6/dart-developer/Counter-class.html
+[`Gauge`]: {{site.dart-api}}/stable/2.19.6/dart-developer/Gauge-class.html
+
+#### `dart:html`
+
+- As previously announced, the deprecated `registerElement`
+  and `registerElement2` methods in `Document` and `HtmlDocument` have been
+  removed.  See [#49536](https://github.com/dart-lang/sdk/issues/49536) for
+  details.
+
+#### `dart:math`
+
+- The `Random` interface can only be implemented, not extended.
+
+#### `dart:io`
+
+- Update `NetworkProfiling` to accommodate new `String` ids
+  that are introduced in vm_service:11.0.0
+
+#### Symptom
+
+Dart analysis (e.g. in your IDE, or in `dart analyze`/`flutter analyze`)
+will fail with errors like:
+
+```plaintext
+error line 2 • Undefined class 'CyclicInitializationError'.
+```
+
+#### Migration
+
+Manually migrate away from using these APIs.
+
+### Extends & implements
+
+Dart 3 supports new [class modifiers][] that
+can restrict the capabilities of a class.
+They have been applied to a number of classes in the core libraries.
+
+#### Scope
+
+This is a [*versioned* change](#unversioned-vs-versioned-changes), 
+that only applies to language version 3.0 or later.
+
+#### `dart:async`
+
+* The following declarations can only be implemented, not extended:
+
+  - `StreamConsumer`
+  - `StreamIterator`
+  - `StreamTransformer`
+  - `MultiStreamController`
+
+  None of these declarations contained any implementation to inherit.
+  They are marked as `interface` to signify that
+  they are only intended as interfaces.
+
+#### `dart:core`
+
+* The `Function` type can no longer be implemented, extended or mixed in.
+  Since Dart 2.0, writing `implements Function` has been allowed
+  for backwards compatibility, but it has not had any effect.
+  In Dart 3.0, the `Function` type is final and cannot be subtyped,
+  preventing code from mistakenly assuming it works.
+
+* The following declarations can only be implemented, not extended:
+
+  - `Comparable`
+  - `Exception`
+  - `Iterator`
+  - `Pattern`
+  - `Match`
+  - `RegExp`
+  - `RegExpMatch`
+  - `StackTrace`
+  - `StringSink`
+
+  None of these declarations contained any implementation to inherit.
+  They are marked as `interface` to signify that
+  they are only intended as interfaces.
+
+* The following declarations can no longer be implemented or extended:
+
+  - `MapEntry`
+  - `OutOfMemoryError`
+  - `StackOverflowError`
+  - `Expando`
+  - `WeakReference`
+  - `Finalizer`
+
+  The `MapEntry` value class is restricted to enable later optimizations.
+  The remaining classes are tightly coupled to the platform and not
+  intended to be subclassed or implemented.
+
+#### `dart:collection`
+
+* The following interface can no longer be extended, only implemented:
+
+  - `Queue`
+
+* The following implementation classes can no longer be implemented:
+
+  - `LinkedList`
+  - `LinkedListEntry`
+
+* The following implementation classes can no longer be implemented
+  or extended:
+
+  - `HasNextIterator` (Also deprecated.)
+  - `HashMap`
+  - `LinkedHashMap`
+  - `HashSet`
+  - `LinkedHashSet`
+  - `DoubleLinkedQueue`
+  - `ListQueue`
+  - `SplayTreeMap`
+  - `SplayTreeSet`
+
+## Dart 3 tools changes
+
+### Removed tools
+
+Historically the Dart team has offered a number of smaller developer tools for
+things like formatting code (`dartfmt`), analyzing code (`dartanalyzer`), etc.
+In Dart 2.10 (October 2020) we introduced a new unified Dart developer tool, the
+[`dart` tool](/tools/dart-tool).
+
+#### Scope
+
+This is an [*unversioned* change](#unversioned-vs-versioned-changes), 
+that applies to all Dart 3 code.
+
+#### Symptom
+
+In Dart 3 these smaller tools do not exist, and
+have been replaced by the new combined `dart` tool.
+
+#### Migration
+
+Use new sub-commands available in the `dart` tool:
+
+| Historical tool | `dart` replacement                            | Deprecation | Discontinuation |
+|-----------------|-----------------------------------------------|-------------|-----------------|
+| `stagehand`     | [`dart create`](/tools/dart-create)           | [2.14](https://github.com/dart-lang/stagehand/issues/671)        | 2.14*  |
+| `dartfmt`       | [`dart format`](/tools/dart-format)           | [2.14](https://github.com/dart-lang/dart_style/issues/986)        | [2.15](https://github.com/dart-lang/dart_style/issues/986)            |
+| `dart2native`   | [`dart compile exe`](/tools/dart-compile#exe) | [2.14](https://github.com/dart-lang/sdk/commit/cac00e9d956a6f7ef28628989912d971f6b908d4)        | [2.15](https://github.com/dart-lang/sdk/commit/6c5fb84716b1f257b170351efe8096fe2af2809b)            |
+| `dart2js`       | [`dart compile js`](/tools/dart-compile)      | [2.17](https://github.com/dart-lang/sdk/commit/8415b70e75b1d5bbe8251fa6a9eab2d970cf9eec)         | [2.18](https://github.com/dart-lang/sdk/commit/69249df50bcc7a0489176efd3fd79fff018f1b91)             |
+| `dartdevc`      | [`webdev`](/tools/webdev)                     | [2.17](https://github.com/dart-lang/sdk/commit/5173fd2d224f669fd8d0a1d21adbfd6187d10f53)         | [2.18](https://github.com/dart-lang/sdk/commit/69249df50bcc7a0489176efd3fd79fff018f1b91)             |
+| `dartanalyzer`  | [`dart analyze`](/tools/dart-analyze)         | [2.16](https://github.com/dart-lang/sdk/commit/f7af5c5256ee6f3a167f380722b96e8af4360b46)         | [2.18](https://github.com/dart-lang/sdk/issues/48457)             |
+| `dartdoc`       | [`dart doc`](/tools/dart-doc)                 | [2.16](https://github.com/dart-lang/sdk/issues/44610)         | [2.17](https://dart-review.googlesource.com/c/sdk/+/228647)             |
+| `pub`           | [`dart pub`](/tools/dart-pub)                 | [2.15](https://github.com/dart-lang/pub/issues/2736)         | [2.17](https://dart-review.googlesource.com/c/sdk/+/234283)             |
+
+{:.table .table-striped .nowrap}
+
+### Null safety migration tools
+
+The following null safety migration commands have been removed,
+as Dart 3 [doesn't support code without null safety](#100-sound-null-safety):
+
+- `dart migrate`
+- `dart pub upgrade --null-safety`
+- `dart pub outdated --mode=null-safety`
+
+#### Scope
+
+This is an [*unversioned* change](#unversioned-vs-versioned-changes), 
+that applies to all Dart 3 code.
+
+#### Symptom
+
+These commands will fail.
+
+#### Migration
+
+Use Dart 2.19 to [migrate to null safety](/null-safety/migration-guide).
+
+### Analyzer config
+
+The [analyzer configuration options][] for 
+enabling stricter checking have changed.
+
+[analyzer configuration options]: /tools/analysis#enabling-additional-type-checks
+
+#### Scope
+
+This is an [*unversioned* change](#unversioned-vs-versioned-changes), 
+that applies to all Dart 3 code.
+
+#### Symptom
+
+The former configuration options will fail with a warning like:
+
+```plaintext
+The option 'implicit-casts' is no longer supported.
+Try using the new 'strict-casts' option.
+```
+
+#### Migration
+
+Replace this part of the analyzer config:
+
+```yaml
+analyzer:
+  strong-mode:
+    implicit-casts: false
+    implicit-dynamic: false
+```
+
+with:
+
+```yaml
+analyzer:
+  language:
+    strict-casts: true
+    strict-raw-types: true
+```
+
+### Other tools changes
+
+* The deprecated Observatory has been hidden by default. 
+  We recommend using [DevTools](/tools/dart-devtools).
+* The command `dart format fix` has been replaced by `dart fix`
+  [#1153](https://github.com/dart-lang/dart_style/issues/1153).
+* The snapshot files bundled in the SDK for the Dart web compiler
+  have been cleaned up [#50700](https://github.com/dart-lang/sdk/issues/50700).
+* The output of `dart format` changed a bit for
+  [some code](https://github.com/dart-lang/sdk/blob/main/CHANGELOG.md#formatter).
+* Ending backwards compatibility for the old location of pub-cache on Windows.
+  Prior to Dart 3 `%APPDATA%\Pub\Cache` was a fallback location for pub-cache.
+  Starting with Dart 3, the default pub-cache is located at
+  `%LOCALAPPDATA%\Pub\Cache`.
+  If you have added globally activated packages to your `PATH`, consider
+  updating `PATH` to contain `%LOCALAPPDATA%\Pub\Cache\bin`.
+
+#### Scope
+
+This is an [*unversioned* change](#unversioned-vs-versioned-changes), 
+that applies to all Dart 3 code.
+
+[records]: /language/records
+[patterns]: /language/patterns
+[class modifiers]: /language/class-modifiers
diff --git a/test_files/source/js-types.md b/test_files/source/js-types.md
new file mode 100644
index 0000000..2d89deb
--- /dev/null
+++ b/test_files/source/js-types.md
@@ -0,0 +1,255 @@
+---
+title: JS types
+description: Usage information about the core types in JS interop.
+---
+
+Dart values and JS values belong to separate language domains. When compiling to
+Wasm, they execute in separate *runtimes* as well. As such, you should treat JS
+values as foreign types. To provide Dart types for JS values,
+[`dart:js_interop`] exposes a set of types prefixed with `JS` called "JS types".
+These types are used to distinguish between Dart values and JS values at
+compile-time.
+
+Importantly, these types are reified differently based on whether you compile to
+Wasm or JS. This means that their runtime type will differ, and therefore you
+[can't use `is` checks and `as` casts](#compatibility-type-checks-and-casts).
+In order to interact with and examine these JS values, you should use
+[`external`] interop members or [conversions](#conversions).
+
+## Type hierarchy
+
+JS types form a natural type hierarchy:
+
+- Top type: `JSAny`, which is any non-nullish JS value
+  - Primitives: `JSNumber`, `JSBoolean`, `JSString`
+  - `JSSymbol`
+  - `JSBigInt`
+  - `JSObject`, which is any JS object
+    - `JSFunction`
+      - `JSExportedDartFunction`, which represents a Dart callback that was
+      converted to a JS function
+    - `JSArray`
+    - `JSPromise`
+    - `JSDataView`
+    - `JSTypedArray`
+      - JS typed arrays like `JSUint8Array`
+    - `JSBoxedDartObject`, which allows users to box and pass Dart values
+      opaquely within the same Dart runtime
+
+You can find the definition of each type in the [`dart:js_interop` API docs].
+
+{% comment %}
+TODO (srujzs): Should we add a tree diagram instead for JS types?
+{% endcomment %}
+
+## Conversions
+
+To use a value from one domain to another, you will likely want to *convert* the
+value to the corresponding type of the other domain. For example, you may want
+to convert a Dart `List<JSString>` into a JS array of strings, which is
+represented by the JS type `JSArray<JSString>`, so that you can pass the array
+to a JS interop API.
+
+Dart supplies a number of conversion members on various Dart types and JS types
+to convert the values between the domains for you.
+
+Members that convert values from Dart to JS usually start with `toJS`:
+
+```dart
+String str = 'hello world';
+JSString jsStr = str.toJS;
+```
+
+Members that convert values from JS to Dart usually start with `toDart`:
+
+```dart
+JSNumber jsNum = ...;
+int integer = jsNum.toDartInt;
+```
+
+Not all JS types have a conversion, and not all Dart types have a conversion.
+Generally, the conversion table looks like the following:
+
+<div class="table-wrapper" markdown="1">
+
+| JS type                             | Dart type                                |
+|-------------------------------------|------------------------------------------|
+| `JSNumber`, `JSBoolean`, `JSString` | `num`, `int`, `double`, `bool`, `String` |
+| `JSExportedDartFunction`            | `Function`                               |
+| `JSArray<T extends JSAny?>`         | `List<T extends JSAny?>`                 |
+| `JSPromise<T extends JSAny?>`       | `Future<T extends JSAny?>`               |
+| Typed arrays like `JSUint8Array`    | Typed lists from `dart:typed_data`       |
+| `JSBoxedDartObject`                 | Opaque Dart value                        |
+
+{:.table .table-striped}
+</div>
+
+:::warning
+Compiling to JavaScript vs Wasm can introduce inconsistencies in both
+performance and semantics for conversions. Conversions may have different costs
+depending on the compiler, so prefer to only convert values if you need to.
+
+Conversions also may or may not produce a new value. This doesn’t matter for
+immutable values like numbers, but does matter for types like `List`. Depending
+on the implementation, a conversion to `JSArray` may return a reference, a
+proxy, or a clone of the original list. To avoid this, do not rely on any
+relation between the `List` and `JSArray` and only rely on their contents being
+the same. Typed array conversions have a similar limitation. Look up the
+specific conversion function for more details.
+:::
+
+## Requirements on `external` declarations and `Function.toJS`
+
+In order to ensure type safety and consistency, the compiler places requirements
+on what types can flow into and out of JS. Passing arbitrary Dart values into JS
+is not allowed. Instead, the compiler requires users to use a compatible interop
+type or a primitive, which would then be implicitly converted by the compiler.
+For example, these would be allowed:
+
+```dart tag=good
+@JS()
+external void primitives(String a, int b, double c, num d, bool e);
+```
+
+```dart tag=good
+@JS()
+external JSArray jsTypes(JSObject _, JSString __);
+```
+
+```dart tag=good
+extension type InteropType(JSObject _) implements JSObject {}
+
+@JS()
+external InteropType get interopType;
+```
+
+Whereas these would return an error:
+
+```dart tag=bad
+@JS()
+external Function get function;
+```
+
+```dart tag=bad
+@JS()
+external set list(List _);
+```
+
+These same requirements exist when you use [`Function.toJS`] to make a Dart
+function callable in JS. The values that flow into and out of this callback must
+be a compatible interop type or a primitive.
+
+If you use a Dart primitive like `String`, an implicit conversion happens in the
+compiler to convert that value from a JS value to a Dart value. If performance
+is critical and you don’t need to examine the contents of the string, then using
+`JSString` instead to avoid the conversion cost may make sense like in the
+second example.
+
+## Compatibility, type checks, and casts
+
+The runtime type of JS types may differ based on the compiler. This affects
+runtime type-checking and casts. Therefore, almost always avoid `is` checks
+where the value is an interop type or where the target type is an interop type:
+
+```dart tag=bad
+void f(JSAny a) {
+  if (a is String) { … }
+}
+```
+
+```dart tag=bad
+void f(JSAny a) {
+  if (a is JSObject) { … }
+}
+```
+
+Also, avoid casts between Dart types and interop types:
+
+```dart tag=bad
+void f(JSString s) {
+  s as String;
+}
+```
+
+To type-check a JS value, use an interop member like [`typeofEquals`] or
+[`instanceOfString`] that examines the JS value itself:
+
+```dart tag=good
+void f(JSAny a) {
+  // Here `a` is verified to be a JS function, so the cast is okay.
+  if (a.typeofEquals('function')) {
+    a as JSFunction;
+  }
+}
+```
+
+From Dart 3.4 onwards, you can use the [`isA`] helper function to check whether
+a value is any interop type:
+
+```dart tag=good
+void f(JSAny a) {
+  if (a.isA<JSString>()) {} // `typeofEquals('string')`
+  if (a.isA<JSArray>()) {} // `instanceOfString('Array')`
+  if (a.isA<CustomInteropType>()) {} // `instanceOfString('CustomInteropType')`
+}
+```
+
+Depending on the type parameter, it'll transform the call into the appropriate
+type-check for that type.
+
+{% comment %}
+TODO: Add a link to and an example using `isA` once it's in a dev release. Users
+should prefer that method if it's available.
+{% endcomment %}
+
+Dart may add lints to make runtime checks with JS interop types easier to avoid.
+See issue [#4841] for more details.
+
+## `null` vs `undefined`
+
+JS has both a `null` and an `undefined` value. This is in contrast with Dart,
+which only has `null`. In order to make JS values more ergonomic to use, if an
+interop member were to return either JS `null` or `undefined`, the compiler maps
+these values to Dart `null`. Therefore a member like `value` in the following
+example can be interpreted as returning a JS object, JS `null`, or `undefined`:
+
+```dart
+@JS()
+external JSObject? get value;
+```
+
+If the return type was not declared as nullable, then the program will throw an
+error if the value returned was JS `null` or `undefined` to ensure soundness.
+
+:::warning
+There is a subtle inconsistency with regards to `undefined` between compiling to
+JS and Wasm. While compiling to JS *treats* `undefined` values as if they were
+Dart `null`, it doesn’t actually *change* the value itself. If an interop member
+returns `undefined` and you pass that value back into JS, JS will see
+`undefined`, *not* `null`, when compiling to JS.
+
+However, when compiling to Wasm, this is not the case,
+and the value will be `null` in JS. This is because
+the compiler implicitly *converts* the value to Dart `null` when compiling to
+Wasm, thereby losing information on whether the original value was JS `null` or
+`undefined`. Avoid writing code where this distinction matters by explicitly
+passing Dart `null` instead to an interop member.
+
+Currently, there's no platform-consistent way to provide `undefined`
+to interop members or distinguish between JS `null` and `undefined` values,
+but this will likely change in the future. See [#54025] for more details.
+:::
+
+{% comment %}
+TODO: add links (with stable) when ready:
+{% endcomment %}
+
+[`dart:js_interop`]: https://api.dart.dev/dev/dart-js_interop/dart-js_interop-library.html
+[`external`]: https://dart.dev/language/functions#external
+[`Function.toJS`]: https://api.dart.dev/dev/dart-js_interop/FunctionToJSExportedDartFunction/toJS.html
+[`dart:js_interop` API docs]: https://api.dart.dev/dev/dart-js_interop/dart-js_interop-library.html#extension-types
+[`typeofEquals`]: https://api.dart.dev/dev/dart-js_interop/JSAnyUtilityExtension/typeofEquals.html
+[`instanceOfString`]: https://api.dart.dev/dev/dart-js_interop/JSAnyUtilityExtension/instanceOfString.html
+[`isA`]: https://api.dart.dev/dev/dart-js_interop/JSAnyUtilityExtension/isA.html
+[#4841]: https://github.com/dart-lang/linter/issues/4841
+[#54025]: https://github.com/dart-lang/sdk/issues/54025
\ No newline at end of file
diff --git a/tests/SevenZipTest.php b/tests/SevenZipTest.php
index 072aef6..87e2eb7 100644
--- a/tests/SevenZipTest.php
+++ b/tests/SevenZipTest.php
@@ -15,9 +15,7 @@ public static function compressAndExtractDataProvider(): array
     $defaultCompressFlags = ['zip', '7z', 'bzip2'];
 
     $testCases = [];
-    foreach ($defaultCompressFlags as $format) {
-      $testCases[$format] = [$format];
-    }
+    foreach ($defaultCompressFlags as $format) $testCases[$format] = [$format];
 
     return $testCases;
   }
@@ -34,7 +32,8 @@ public static function tearDownAfterClass(): void
   protected function setUp(): void
   {
     $this->sevenZip = new SevenZip();
-    $this->testDir  = realpath(__DIR__ . '/../test_files');
+    $this->sevenZip->mmt(true);
+    $this->testDir = realpath(__DIR__ . '/../test_files');
   }
 
   public static function clearDirectory($directory)
@@ -50,17 +49,178 @@ public static function clearDirectory($directory)
     }
   }
 
+  private static function getPrivateProperty($object, $propertyName)
+  {
+    $reflection = new \ReflectionClass(get_class($object));
+    $property   = $reflection->getProperty($propertyName);
+    $property->setAccessible(true);
+    return $property->getValue($object);
+  }
+
+  public function testGetSevenZipPath(): void
+  {
+    $sevenZipPath = $this->sevenZip->getSevenZipPath();
+    $this->assertIsString($sevenZipPath);
+    $this->assertStringContainsString('7z', $sevenZipPath);
+  }
+
+  public function testSetSevenZipPath(): void
+  {
+    $customPath = '/custom/path/to/7z';
+    $this->sevenZip->setSevenZipPath($customPath);
+    $this->assertEquals($customPath, $this->sevenZip->getSevenZipPath());
+  }
+
+  public function testFlagrize(): void
+  {
+    $flags = [
+      'a' => null,
+      'b' => 'value1',
+      'c' => 123,
+    ];
+
+    $expected = ['-a', '-b=value1', '-c=123'];
+    $result   = $this->sevenZip->flagrize($flags);
+    $this->assertEquals($expected, $result);
+  }
+
+  public function testGetAndSetAlwaysFlags(): void
+  {
+    $getAlwaysFlags = $this->getProtectedMethod($this->sevenZip, 'getAlwaysFlags');
+    $setAlwaysFlags = $this->getProtectedMethod($this->sevenZip, 'setAlwaysFlags');
+
+    $originalFlags = $getAlwaysFlags->invoke($this->sevenZip);
+    $newFlags      = ['foo', 'bar' => 'baz'];
+    $setAlwaysFlags->invoke($this->sevenZip, $newFlags);
+
+    $this->assertEquals($newFlags, $getAlwaysFlags->invoke($this->sevenZip));
+
+    $setAlwaysFlags->invoke($this->sevenZip, $originalFlags);
+  }
+
+  private static function getProtectedMethod($object, $methodName)
+  {
+    $reflection = new \ReflectionClass(get_class($object));
+    $method     = $reflection->getMethod($methodName);
+    $method->setAccessible(true);
+    return $method;
+  }
+
+  public function testReset(): void
+  {
+    $this->sevenZip->addFlag('custom', 'value');
+    $this->sevenZip->setProgressCallback(function () { });
+    $this->sevenZip->setFormat('zip');
+    $this->sevenZip->setTargetPath('/path/to/target');
+    $this->sevenZip->setSourcePath('/path/to/source');
+
+    $this->sevenZip->reset();
+
+    $this->assertEmpty($this->sevenZip->getCustomFlags());
+    $this->assertNull($this->sevenZip->getProgressCallback());
+    $this->assertEquals('7z', $this->sevenZip->getFormat());
+    $this->assertEmpty($this->sevenZip->getTargetPath());
+    $this->assertEmpty($this->sevenZip->getSourcePath());
+  }
+
+  public function testProgress(): void
+  {
+    $callback = function () { };
+    $this->sevenZip->progress($callback);
+    $this->assertEquals($callback, $this->sevenZip->getProgressCallback());
+  }
+
+  public function testFasterAndSlower(): void
+  {
+    $this->sevenZip->format('zstd');
+    $this->sevenZip->faster();
+    $this->assertEquals(['mx' => 0, 'mmt' => 'on'], $this->sevenZip->getCustomFlags());
+
+    $this->sevenZip->slower();
+    $this->assertEquals(['mx' => 22, 'mmt' => 'on'], $this->sevenZip->getCustomFlags());
+
+    $this->sevenZip->format('7z');
+    $this->sevenZip->faster();
+    $this->assertEquals(['mx' => 1, 'mmt' => 'on'], $this->sevenZip->getCustomFlags());
+
+    $this->sevenZip->slower();
+    $this->assertEquals(['mx' => 9, 'mmt' => 'on'], $this->sevenZip->getCustomFlags());
+  }
+
+  public function testUltraZip(): void
+  {
+    $this->sevenZip->format('zip');
+    $this->sevenZip->ultra();
+    $expected = [
+      'mmt'   => 'on',
+      'mx'    => 9,
+      'mm'    => 'Deflate64',
+      'mfb'   => 257,
+      'mpass' => 15,
+      'mmem'  => 28,
+    ];
+    $this->assertEquals($expected, $this->sevenZip->getCustomFlags());
+  }
+
+  public function testUltraZstd(): void
+  {
+
+    $this->sevenZip->format('zstd');
+    $this->sevenZip->ultra();
+    $expected = [
+      'mmt' => 'on',
+      'mx'  => 22,
+    ];
+    $this->assertEquals($expected, $this->sevenZip->getCustomFlags());
+  }
+
+  public function testUltra7z(): void
+  {
+
+
+    $this->sevenZip->format('7z');
+    $this->sevenZip->ultra();
+    $expected = [
+      'mmt' => 'on',
+      'mx'  => 9,
+      'm0'  => 'lzma2',
+      'mfb' => 64,
+      'ms'  => 'on',
+      'md'  => '32m',
+    ];
+    $this->assertEquals($expected, $this->sevenZip->getCustomFlags());
+
+  }
+
+  public function testCopy(): void
+  {
+    $this->sevenZip->copy();
+    $expected = [
+      'mmt' => 'on',
+      'mx'  => 0,
+      'm0'  => 'Copy',
+      'mm'  => 'Copy',
+      'myx' => 0,
+    ];
+    $this->assertEquals($expected, $this->sevenZip->getCustomFlags());
+  }
+
   /**
    * @dataProvider compressAndExtractDataProvider
    */
   public function testCompress(string $format): void
   {
-    $sourcePath  = $this->testDir . '/source';
-    $archivePath = $this->testDir . '/target/archive.' . $format;
+    $directory = $this->testDir . '/source';
+    $archive   = $this->testDir . '/target/archive.' . $format;
 
     // Compress
-    $this->sevenZip->compress(format: $format, archivePath: $archivePath, sourcePath: $sourcePath);
-    $this->assertFileExists(filename: $archivePath);
+    $this->sevenZip
+      ->format($format)
+      ->source(path: $directory)
+      ->target(path: $archive)
+      ->compress();
+
+    $this->assertFileExists(filename: $archive);
   }
 
   /**
@@ -69,34 +229,63 @@ public function testCompress(string $format): void
    */
   public function testExtract(string $format): void
   {
-    $archivePath = $this->testDir . '/target/archive.' . $format;
-    $extractPath = $this->testDir . '/extract/' . $format;
-    self::clearDirectory($extractPath);
+    $archive = $this->testDir . '/target/archive.' . $format;
+    $target  = $this->testDir . '/extract/' . $format;
+    self::clearDirectory($target);
 
+    $this->sevenZip
+      ->source(path: $archive)
+      ->target(path: $target)
+      ->extract();
+    $this->assertFileExists(filename: $target . '/source/Avatart.svg');
+    $this->assertFileExists(filename: $target . '/source/js_interop.dart');
 
-    // Extract
-    $this->sevenZip->extract(format: $format, archivePath: $archivePath, extractPath: $extractPath);
-    $this->assertFileExists(filename: $extractPath . '/source/Avatart.svg');
-    $this->assertFileExists(filename: $extractPath . '/source/js_interop.dart');
-
-    unlink($archivePath);
+    unlink($archive);
   }
 
   public function testAddAndRemoveFlag(): void
   {
-    $flag = '-mx=9';
-    $this->sevenZip->addCompressFlag($flag);
-    $this->assertContains($flag, self::getPrivateProperty($this->sevenZip, 'customCompressFlags'));
+    $flag  = 'mx';
+    $value = 9;
+    $this->sevenZip->addFlag($flag, $value);
+    $customFlags = $this->sevenZip->getCustomFlags();
+    $this->assertArrayHasKey($flag, $customFlags);
+    $this->assertEquals($value, $customFlags[$flag]);
 
-    $this->sevenZip->removeCompressFlag($flag);
-    $this->assertNotContains($flag, self::getPrivateProperty($this->sevenZip, 'customCompressFlags'));
+    $this->sevenZip->removeFlag($flag);
+    $customFlags = $this->sevenZip->getCustomFlags();
+    $this->assertArrayNotHasKey($flag, $customFlags);
   }
 
-  private static function getPrivateProperty($object, $propertyName)
+  /**
+   * @depends testExtract
+   */
+  public function testSetProgressCallback(): void
   {
-    $reflection = new \ReflectionClass(get_class($object));
-    $property   = $reflection->getProperty($propertyName);
-    $property->setAccessible(true);
-    return $property->getValue($object);
+    $progressHistory = [];
+    $callback        = function ($progress) use (&$progressHistory) {
+      $progressHistory[] = $progress;
+    };
+
+    $directory = $this->testDir . '/source';
+    $archive   = $this->testDir . '/target/archive.7z';
+
+    $this->sevenZip
+      ->setProgressCallback($callback)
+      ->mx(9)
+      ->compress('zstd', $directory, $archive);
+
+    $this->assertNotEmpty($progressHistory);
+    $this->assertEquals(100, last($progressHistory));
+  }
+
+  public function testGetDefaultCompressFlags(): void
+  {
+    $defaultFlags = self::getProtectedMethod($this->sevenZip, 'getDefaultCompressFlags');
+
+    $this->assertEquals(['tzip'], $defaultFlags->invoke($this->sevenZip, 'zip'));
+    $this->assertEquals(['t7z', 'm0' => 'lzma2'], $defaultFlags->invoke($this->sevenZip, '7z'));
+    $this->assertEquals(['t7z', 'm0' => 'bzip2'], $defaultFlags->invoke($this->sevenZip, 'bzip2'));
+    $this->assertEquals(['tmy_format'], $defaultFlags->invoke($this->sevenZip, 'my_format'));
   }
 }
diff --git a/try.php b/try.php
index 4bb5a7f..607fbf6 100644
--- a/try.php
+++ b/try.php
@@ -5,9 +5,9 @@
 
 use Verseles\SevenZip\SevenZip;
 
-$archivePath    = './test_files/target/archive.7z';
-$extractPath    = './test_files/extract';
-$fileToCompress = 'try.php';
+$archivePath    = '/Users/helio/zip-tiny.7z';
+$extractPath    = '/Users/helio/tmp';
+$fileToCompress = '/Users/helio/zip-tiny';
 
 @unlink($archivePath);
 @unlink($extractPath . '/' . $fileToCompress);
@@ -17,13 +17,59 @@
 echo "✅\n";
 
 echo 'Compressing archive... ';
-$sevenZip->compress('7z', $archivePath, $fileToCompress);
+$sevenZip
+  ->setProgressCallback(function ($progress) {
+    echo "\n" . $progress . "%\n";
+  })
+  ->format('7z')
+  ->source($fileToCompress)
+  ->target($archivePath)
+  ->compress();
 echo "✅\n";
 
 echo 'Extracting archive... ';
-$sevenZip->extract('7z', $archivePath, $extractPath);
+$sevenZip
+  ->setProgressCallback(function ($progress) {
+    echo "\n" . $progress . "%\n";
+  })
+  ->source($archivePath)
+  ->target($extractPath)
+  ->extract();
 echo "✅\n";
 
 echo "Deleting archive... ";
 unlink($archivePath);
 echo "✅\n";
+
+echo "Clearing directory... ";
+clearDirectory($extractPath);
+echo "✅\n";
+
+/**
+ * Clears a directory by removing all files and subdirectories within it,
+ * but leaves the directory itself intact.
+ *
+ * @param string $dir The path to the directory to be cleared.
+ * @return bool Returns true on success, false on failure.
+ */
+function clearDirectory($dir)
+{
+  if (!is_dir($dir)) {
+    return false;
+  }
+
+  $files = array_diff(scandir($dir), ['.', '..']);
+
+  foreach ($files as $file) {
+    $filePath = $dir . '/' . $file;
+
+    if (is_dir($filePath)) {
+      clearDirectory($filePath);
+      rmdir($filePath);
+    } else {
+      unlink($filePath);
+    }
+  }
+
+  return true;
+}