fix(@angular-devkit/build-angular): disable Worker wait loop for TS/NG parallel compilation in web containers

clydin · alan-agius4 · commit 6f9ef1fbb147 · 2023-11-08T15:04:20.000+01:00
When using the `application` builder, a parallel TS/NG compilation is used that is run inside a Node.js Worker.
This Worker by default uses an Atomics-based wait loop to improve performance while waiting for messages. This
loop relies on the synchronous API `receiveMessageOnPort`. While this works well in Node.js, the web container
execution environment does not currently support passing transferable objects via `receiveMessageOnPort`. Attempting
to do so will cause a serialization error and a failed application build. To avoid this problem, the wait loop
optimization is disabled when the web container execution environment is detected. This change is only needed
for the TS/NG compilation as no other parallel operation within the build system currently uses `receiveMessageOnPort`
with transferable objects.
diff --git a/packages/angular_devkit/build_angular/src/tools/esbuild/angular/compilation/parallel-compilation.ts b/packages/angular_devkit/build_angular/src/tools/esbuild/angular/compilation/parallel-compilation.ts
@@ -36,6 +36,9 @@ export class ParallelCompilation extends AngularCompilation {
       minThreads: 1,
       maxThreads: 1,
       idleTimeout: Infinity,
+      // Web containers do not support transferable objects with receiveOnMessagePort which
+      // is used when the Atomics based wait loop is enable.
+      useAtomics: !process.versions.webcontainer,
       filename: localRequire.resolve('./parallel-worker'),
     });
   }
