speced · marcoscaceres · Feb 7, 2019 · Feb 6, 2019 · Feb 6, 2019 · Feb 6, 2019
diff --git a/src/core/defaults.js b/src/core/defaults.js
@@ -2,6 +2,7 @@
  * Sets the core defaults
  */
 export const name = "core/defaults";
+import { rule as checkCharset } from "./linter-rules/check-charset";
 import { rule as checkInternalSlots } from "./linter-rules/check-internal-slots";
 import { rule as checkPunctuation } from "./linter-rules/check-punctuation";
 import linter from "./linter";
@@ -14,7 +15,8 @@ linter.register(
   noHeadinglessSectionsRule,
   checkPunctuation,
   localRefsExist,
-  checkInternalSlots
+  checkInternalSlots,
+  checkCharset
 );
 
 export const coreDefaults = {
@@ -24,6 +26,7 @@ export const coreDefaults = {
     "check-punctuation": false,
     "local-refs-exist": true,
     "check-internal-slots": false,
+    "check-charset": false,
   },
   pluralize: false,
   specStatus: "base",

diff --git a/src/core/linter-rules/check-charset.js b/src/core/linter-rules/check-charset.js
@@ -0,0 +1,52 @@
+/**
+ * Linter rule "check-charset".
+ *
+ * Checks whether the document has `<meta charset="utf-8">` properly.
+ */
+import LinterRule from "../LinterRule";
+import { lang as defaultLang } from "../l10n";
+
+const name = "check-charset";
+const meta = {
+  en: {
+    description: `Document must only contain one \`<meta>\` tag with charset set to 'utf-8'`,
+    howToFix: `Add this line in your document \`<head>\` section - \`<meta charset="utf-8">\` or set charset to "utf-8" if not set already.`,
+  },
+};
+
+// Fall back to english, if language is missing
+const lang = defaultLang in meta ? defaultLang : "en";
+
+/**
+ * Runs linter rule.
+ *
+ * @param {Object} conf The ReSpec config.
+ * @param {Document} doc The document to be checked.
+ */
+function linterFunction(conf, doc) {
+  const metas = doc.querySelectorAll("meta[charset]");
+  const val = [];
+  for (const meta of metas) {
+    val.push(
+      meta
+        .getAttribute("charset")
+        .trim()
+        .toLowerCase()
+    );
+  }
+  const utfExists = val.includes("utf-8");
+
+  //only a single meta[charset] and is set to utf-8, correct case
+  if (utfExists && metas.length === 1) {
+    return [];
+  }
+  //if more than one meta[charset] tag defined along with utf-8
+  //or
+  //no meta[charset] present in the document
+  return {
+    name,
+    occurrences: metas.length,
+    ...meta[lang],
+  };
+}
+export const rule = new LinterRule(name, linterFunction);
diff --git a/tests/spec/core/linter-rules/check-charset-spec.js b/tests/spec/core/linter-rules/check-charset-spec.js
@@ -0,0 +1,72 @@
+describe("Core Linter Rule - 'check-charset'", () => {
+  const ruleName = "check-charset";
+  const config = {
+    lint: { [ruleName]: true },
+  };
+  let rule;
+  beforeAll(async () => {
+    rule = await new Promise(resolve => {
+      require([`core/linter-rules/${ruleName}`], ({ rule }) => resolve(rule));
+    });
+  });
+
+  it("checks if meta[charset] is set to utf-8", async () => {
+    const doc = document.implementation.createHTMLDocument("test doc");
+    doc.head.innerHTML = `
+      <meta charset="utf-8">
+      <meta name="viewport" content="width=device-width">
+      <title>ReSpec</title>
+    `;
+
+    const results = await rule.lint(config, doc);
+    expect(results.length).toBe(0);
+  });
+
+  it("doesn't give an error when written in capitals", async () => {
+    const doc = document.implementation.createHTMLDocument("test doc");
+    doc.head.innerHTML = `
+      <meta charset="UTF-8">
+      <meta name="viewport" content="width=device-width">
+      <title>ReSpec</title>
+    `;
+
+    const results = await rule.lint(config, doc);
+    expect(results.length).toBe(0);
+  });
+
+  it("checks if meta[charset] is present or not", async () => {
+    const doc = document.implementation.createHTMLDocument("test doc");
+    doc.head.innerHTML = `
+      <meta name="viewport" content="width=device-width">
+      <title>ReSpec</title>
+    `;
+
+    const results = await rule.lint(config, doc);
+    expect(results.occurrences).toBe(0);
+  });
+
+  it("returns error when more then one meta[charset] present", async () => {
+    const doc = document.implementation.createHTMLDocument("test doc");
+    doc.head.innerHTML = `
+      <meta charset="utf-8">
+      <meta charset="ascii-128">
+      <meta name="viewport" content="width=device-width">
+      <title>ReSpec</title>
+    `;
+
+    const results = await rule.lint(config, doc);
+    expect(results.occurrences).toBe(2);
+  });
+
+  it("return error when some other charset defined", async () => {
+    const doc = document.implementation.createHTMLDocument("test doc");
+    doc.head.innerHTML = `
+      <meta charset="ascii-128">
+      <meta name="viewport" content="width=device-width">
+      <title>ReSpec</title>
+    `;
+
+    const results = await rule.lint(config, doc);
+    expect(results.occurrences).toBe(1);
+  });
+});
diff --git a/tests/spec/w3c/defaults-spec.js b/tests/spec/w3c/defaults-spec.js
@@ -15,6 +15,7 @@ describe("W3C — Defaults", () => {
       "local-refs-exist": true,
       "check-punctuation": false,
       "check-internal-slots": false,
+      "check-charset": false,
     });
     expect(rsConf.highlightVars).toEqual(true);
     expect(rsConf.license).toEqual("w3c-software-doc");
@@ -51,6 +52,7 @@ describe("W3C — Defaults", () => {
       "check-punctuation": false,
       "fake-linter-rule": "foo",
       "check-internal-slots": true,
+      "check-charset": false,
     });
     expect(rsConf.highlightVars).toEqual(false);
     expect(rsConf.license).toEqual("c0");