[heft-typescript@next] Add "useTranspilerWorker" option

.vscode/launch.json

@@ -39,6 +39,24 @@
 			"console": "integratedTerminal",
 			"internalConsoleOptions": "neverOpen"
 		},
+		{
+			"type": "node",
+			"request": "launch",
+			"name": "Debug Build in Selected Project (Heft)",
+			"cwd": "${fileDirname}",
+			"runtimeArgs": [
+				"--nolazy",
+				"--inspect-brk",
+				"${workspaceFolder}/apps/heft/lib/start.js",
+				"--debug",
+				"build"
+			],
+			"skipFiles": ["<node_internals>/**"],
+			"outFiles": [],
+			"sourceMaps": true,
+			"console": "integratedTerminal",
+			"internalConsoleOptions": "neverOpen"
+		},
 		{
 			"name": "Attach",
 			"type": "node",

build-tests/heft-typescript-composite-test/src/indexA.ts

@@ -8,3 +8,5 @@ import(/* webpackChunkName: 'chunk' */ './chunks/ChunkClass')
   .catch((e) => {
     console.log('Error: ' + e.message);
   });
+
+export {};

build-tests/heft-typescript-composite-test/src/indexB.ts

@@ -1 +1,3 @@
 console.log('dostuff');
+
+export {};

build-tests/heft-typescript-composite-test/tsconfig-base.json

@@ -16,6 +16,9 @@
     "noUnusedLocals": true,
     "types": ["heft-jest", "webpack-env"],
 
+    "isolatedModules": true,
+    "importsNotUsedAsValues": "error",
+
     "module": "esnext",
     "moduleResolution": "node",
     "target": "es5",

build-tests/heft-webpack4-everything-test/config/typescript.json

@@ -55,5 +55,7 @@
     // "excludeGlobs": [
     //   "some/path/*.css"
     // ]
-  }
+  },
+
+  "useTranspilerWorker": true
 }

build-tests/heft-webpack4-everything-test/package.json

@@ -5,7 +5,7 @@
   "private": true,
   "scripts": {
     "build": "heft build --clean",
-    "start": "heft start",
+    "start": "heft build-watch --serve",
     "_phase:build": "heft run --only build -- --clean",
     "_phase:test": "heft run --only test -- --clean"
   },

build-tests/heft-webpack4-everything-test/src/indexA.ts

@@ -8,3 +8,5 @@ import(/* webpackChunkName: 'chunk' */ './chunks/ChunkClass')
   .catch((e) => {
     console.log('Error: ' + e.message);
   });
+
+export {};

build-tests/heft-webpack4-everything-test/src/indexB.ts

@@ -1 +1,3 @@
 console.log('dostuff');
+
+export {};

build-tests/heft-webpack4-everything-test/tsconfig.json

@@ -16,6 +16,7 @@
     "noUnusedLocals": true,
     "types": ["heft-jest", "webpack-env"],
     "incremental": true,
+    "isolatedModules": true,
 
     "module": "esnext",
     "moduleResolution": "node",

common/reviews/api/heft-typescript-plugin.api.md

@@ -59,6 +59,7 @@ export interface ITypeScriptConfigurationJson {
     // (undocumented)
     project?: string;
     staticAssetsToCopy?: IStaticAssetsCopyConfiguration;
+    useTranspilerWorker?: boolean;
 }
 
 // @beta (undocumented)

heft-plugins/heft-typescript-plugin/src/TranspilerWorker.ts

@@ -0,0 +1,104 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
+// See LICENSE in the project root for license information.
+import { parentPort, workerData } from 'node:worker_threads';
+
+import type * as TTypescript from 'typescript';
+import type {
+  ITranspilationErrorMessage,
+  ITranspilationRequestMessage,
+  ITranspilationSuccessMessage,
+  ITypescriptWorkerData
+} from './types';
+import type { ExtendedTypeScript } from './internalTypings/TypeScriptInternals';
+import { configureProgramForMultiEmit } from './configureProgramForMultiEmit';
+
+const typedWorkerData: ITypescriptWorkerData = workerData;
+
+const ts: ExtendedTypeScript = require(typedWorkerData.typeScriptToolPath);
+
+function handleMessage(message: ITranspilationRequestMessage | false): void {
+  if (!message) {
+    process.exit(0);
+  }
+
+  try {
+    const response: ITranspilationSuccessMessage = runTranspiler(message);
+    parentPort!.postMessage(response);
+  } catch (err) {
+    const errorResponse: ITranspilationErrorMessage = {
+      requestId: message.requestId,
+      type: 'error',
+      result: {
+        message: err.message,
+        ...Object.fromEntries(Object.entries(err))
+      }
+    };
+    parentPort!.postMessage(errorResponse);
+  }
+}
+
+function runTranspiler(message: ITranspilationRequestMessage): ITranspilationSuccessMessage {
+  const { requestId, compilerOptions, moduleKindsToEmit, fileNames } = message;
+
+  const fullySkipTypeCheck: boolean =
+    compilerOptions.importsNotUsedAsValues === ts.ImportsNotUsedAsValues.Error;
+
+  for (const [option, value] of Object.entries(ts.getDefaultCompilerOptions())) {
+    if (compilerOptions[option] === undefined) {
+      compilerOptions[option] = value;
+    }
+  }
+
+  const { target: rawTarget } = compilerOptions;
+
+  for (const option of ts.transpileOptionValueCompilerOptions) {
+    compilerOptions[option.name] = option.transpileOptionValue;
+  }
+
+  compilerOptions.suppressOutputPathCheck = true;
+  compilerOptions.skipDefaultLibCheck = true;
+  compilerOptions.preserveValueImports = true;
+
+  const sourceFileByPath: Map<string, TTypescript.SourceFile> = new Map();
+
+  for (const fileName of fileNames) {
+    const sourceText: string | undefined = ts.sys.readFile(fileName);
+    if (sourceText) {
+      const sourceFile: TTypescript.SourceFile = ts.createSourceFile(fileName, sourceText, rawTarget!);
+      sourceFile.hasNoDefaultLib = fullySkipTypeCheck;
+      sourceFileByPath.set(fileName, sourceFile);
+    }
+  }
+
+  const newLine: string = ts.getNewLineCharacter(compilerOptions);
+
+  const compilerHost: TTypescript.CompilerHost = {
+    getSourceFile: (fileName: string) => sourceFileByPath.get(fileName),
+    writeFile: ts.sys.writeFile,
+    getDefaultLibFileName: () => 'lib.d.ts',
+    useCaseSensitiveFileNames: () => true,
+    getCanonicalFileName: (fileName: string) => fileName,
+    getCurrentDirectory: () => '',
+    getNewLine: () => newLine,
+    fileExists: (fileName: string) => sourceFileByPath.has(fileName),
+    readFile: () => '',
+    directoryExists: () => true,
+    getDirectories: () => []
+  };
+
+  const program: TTypescript.Program = ts.createProgram(fileNames, compilerOptions, compilerHost);
+
+  configureProgramForMultiEmit(program, ts, moduleKindsToEmit, 'transpile');
+
+  const result: TTypescript.EmitResult = program.emit(undefined, undefined, undefined, undefined, undefined);
+
+  const response: ITranspilationSuccessMessage = {
+    requestId,
+    type: 'success',
+    result
+  };
+
+  return response;
+}
+
+parentPort!.on('message', handleMessage);