fix(@angular-devkit/build-angular): explicitly send options to JS transformer workers

When using the experimental esbuild-based browser application builder, the JavaScript
transformation workers will now only receive the explicit options expected. Previously,
additional Angular compiler plugin options could have been serialized and sent as well.
While these would be unused, there was no need to serialize/deserialize these option values.

Author: clydin

packages/angular_devkit/build_angular/src/builders/browser-esbuild/javascript-transformer.ts

@@ -26,12 +26,21 @@ export interface JavaScriptTransformerOptions {
  */
 export class JavaScriptTransformer {
   #workerPool: Piscina;
+  #commonOptions: Required<JavaScriptTransformerOptions>;
 
-  constructor(private options: JavaScriptTransformerOptions, maxThreads?: number) {
+  constructor(options: JavaScriptTransformerOptions, maxThreads?: number) {
     this.#workerPool = new Piscina({
       filename: require.resolve('./javascript-transformer-worker'),
       maxThreads,
     });
+
+    // Extract options to ensure only the named options are serialized and sent to the worker
+    const { sourcemap, thirdPartySourcemaps = false, advancedOptimizations = false } = options;
+    this.#commonOptions = {
+      sourcemap,
+      thirdPartySourcemaps,
+      advancedOptimizations,
+    };
   }
 
   /**
@@ -45,7 +54,7 @@ export class JavaScriptTransformer {
     // they may need linking. The data is also not yet available to perform most transformation checks.
     return this.#workerPool.run({
       filename,
-      ...this.options,
+      ...this.#commonOptions,
     });
   }
 
@@ -61,7 +70,7 @@ export class JavaScriptTransformer {
     // Perform a quick test to determine if the data needs any transformations.
     // This allows directly returning the data without the worker communication overhead.
     let forceAsyncTransformation;
-    if (skipLinker && !this.options.advancedOptimizations) {
+    if (skipLinker && !this.#commonOptions.advancedOptimizations) {
       // If the linker is being skipped and no optimizations are needed, only async transformation is left.
       // This checks for async generator functions. All other async transformation is handled by esbuild.
       forceAsyncTransformation = data.includes('async') && /async\s+function\s*\*/.test(data);
@@ -77,7 +86,7 @@ export class JavaScriptTransformer {
       // Send the async check result if present to avoid rechecking in the worker
       forceAsyncTransformation,
       skipLinker,
-      ...this.options,
+      ...this.#commonOptions,
     });
   }