[api-extractor] Upgrade bundled TypeScript to 5.9

Author: jahanford

apps/api-extractor/package.json

@@ -75,7 +75,7 @@
     "resolve": "~1.22.1",
     "semver": "~7.5.4",
     "source-map": "~0.6.1",
-    "typescript": "5.8.2"
+    "typescript": "5.9.3"
   },
   "devDependencies": {
     "@rushstack/heft": "1.2.7",

apps/api-extractor/src/analyzer/TypeScriptInternals.ts

@@ -17,7 +17,7 @@ export interface IGlobalVariableAnalyzer {
 export class TypeScriptInternals {
   public static getImmediateAliasedSymbol(symbol: ts.Symbol, typeChecker: ts.TypeChecker): ts.Symbol {
     // Compiler internal:
-    // https://github.com/microsoft/TypeScript/blob/v3.2.2/src/compiler/checker.ts
+    // https://github.com/microsoft/TypeScript/blob/v5.9.3/src/compiler/checker.ts
     return (typeChecker as any).getImmediateAliasedSymbol(symbol);
   }
 
@@ -61,7 +61,7 @@ export class TypeScriptInternals {
    */
   public static getJSDocCommentRanges(node: ts.Node, text: string): ts.CommentRange[] | undefined {
     // Compiler internal:
-    // https://github.com/microsoft/TypeScript/blob/v2.4.2/src/compiler/utilities.ts#L616
+    // https://github.com/microsoft/TypeScript/blob/v5.9.3/src/compiler/utilities.ts#L2710
 
     return (ts as any).getJSDocCommentRanges.apply(this, arguments);
   }
@@ -73,7 +73,7 @@ export class TypeScriptInternals {
     node: ts.Identifier | ts.StringLiteralLike | ts.NumericLiteral
   ): string {
     // Compiler internal:
-    // https://github.com/microsoft/TypeScript/blob/v3.2.2/src/compiler/utilities.ts#L2721
+    // https://github.com/microsoft/TypeScript/blob/v5.9.3/src/compiler/utilities.ts#L5368
 
     return (ts as any).getTextOfIdentifierOrLiteral(node);
   }
@@ -89,7 +89,7 @@ export class TypeScriptInternals {
     mode: ts.ModuleKind.CommonJS | ts.ModuleKind.ESNext | undefined
   ): ts.ResolvedModuleFull | undefined {
     // Compiler internal:
-    // https://github.com/microsoft/TypeScript/blob/v5.3.3/src/compiler/types.ts#L4698
+    // https://github.com/microsoft/TypeScript/blob/v5.9.3/src/compiler/types.ts#L5064
     const result: ts.ResolvedModuleWithFailedLookupLocations | undefined = (program as any).getResolvedModule(
       sourceFile,
       moduleNameText,
@@ -107,7 +107,7 @@ export class TypeScriptInternals {
     compilerOptions: ts.CompilerOptions
   ): ts.ModuleKind.CommonJS | ts.ModuleKind.ESNext | undefined {
     // Compiler internal:
-    // https://github.com/microsoft/TypeScript/blob/v5.8.2/src/compiler/program.ts#L931
+    // https://github.com/microsoft/TypeScript/blob/v5.9.3/src/compiler/program.ts#L932
 
     return ts.getModeForUsageLocation?.(file, usage, compilerOptions);
   }

common/changes/@microsoft/api-extractor/jahanford-ts-59_2026-03-26-15-05.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/api-extractor",
+      "comment": "Upgrade the bundled compiler engine to TypeScript 5.9.3",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@microsoft/api-extractor"
+}

common/config/subspaces/build-tests-subspace/pnpm-lock.yaml

@@ -1,6 +1,6 @@
 // DO NOT MODIFY THIS FILE MANUALLY BUT DO COMMIT IT. It is generated and used by Rush.
 {
-  "pnpmShrinkwrapHash": "ae06e3ff5f65c89fd6b5c88cb4bce597f4a5aa18",
+  "pnpmShrinkwrapHash": "306357c78efe97f545fc0681fdb84d17f79bbbb2",
   "preferredVersionsHash": "550b4cee0bef4e97db6c6aad726df5149d20e7d9",
-  "packageJsonInjectedDependenciesHash": "fa90a0a032a0046e646e8751bbc6d0be86a4dda1"
+  "packageJsonInjectedDependenciesHash": "0750dcefdccb64160667c86a2af1ba7854f159e2"
 }

common/config/subspaces/build-tests-subspace/repo-state.json

@@ -106,8 +106,9 @@
       // For testing Heft with TS V4
       "~4.9.5",
 
+      "5.8.2",
       // API Extractor bundles a specific TypeScript version because it calls internal APIs
-      "5.8.2"
+      "5.9.3"
     ],
     "source-map": [
       "~0.6.1" // API Extractor is using an older version of source-map because newer versions are async

common/config/subspaces/default/common-versions.json

@@ -1,5 +1,5 @@
 // DO NOT MODIFY THIS FILE MANUALLY BUT DO COMMIT IT. It is generated and used by Rush.
 {
-  "pnpmShrinkwrapHash": "c482c23c40b202ed750549c796c24b3550d0ba6e",
+  "pnpmShrinkwrapHash": "8821e1e50d94962f6d01f6b347c1a79a584bc961",
   "preferredVersionsHash": "029c99bd6e65c5e1f25e2848340509811ff9753c"
 }