From d60608aad1576efe2526decd6046540842612ffb Mon Sep 17 00:00:00 2001
From: Jason Morse <35609178+JasonVMo@users.noreply.github.com>
Date: Thu, 23 Jan 2025 01:42:08 -0800
Subject: [PATCH] feat(typescript-service): pick up the writeFile override from
 the LanguageServiceHost when it is overridden (#3491)

---
 .changeset/serious-olives-relate.md        | 6 ++++++
 packages/typescript-service/src/project.ts | 5 ++++-
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/serious-olives-relate.md

diff --git a/.changeset/serious-olives-relate.md b/.changeset/serious-olives-relate.md
new file mode 100644
index 000000000..ee59ae819
--- /dev/null
+++ b/.changeset/serious-olives-relate.md
@@ -0,0 +1,6 @@
+---
+"@rnx-kit/typescript-service": patch
+---
+
+Projects should use the writeFile set in the LanguageServiceHost to write files
+if it is overridden.
diff --git a/packages/typescript-service/src/project.ts b/packages/typescript-service/src/project.ts
index c296fe1d6..dbcd4c811 100644
--- a/packages/typescript-service/src/project.ts
+++ b/packages/typescript-service/src/project.ts
@@ -10,6 +10,7 @@ export class Project {
   private externalFiles: ExternalFileCache;
 
   private languageService: ts.LanguageService;
+  private writeFile: (fileName: string, content: string) => void;
 
   constructor(
     documentRegistry: ts.DocumentRegistry,
@@ -93,6 +94,8 @@ export class Project {
     if (enhanceLanguageServiceHost) {
       enhanceLanguageServiceHost(languageServiceHost);
     }
+    // if someone replaces writeFile when they enhance the language service host, use that for writing
+    this.writeFile = languageServiceHost.writeFile || ts.sys.writeFile;
 
     this.languageService = ts.createLanguageService(
       languageServiceHost,
@@ -157,7 +160,7 @@ export class Project {
       return false;
     }
     output.outputFiles.forEach((o) => {
-      ts.sys.writeFile(o.name, o.text);
+      this.writeFile(o.name, o.text);
     });
     return true;
   }