fix(@angular/build): added JavaScriptTransformer close to dispose method

This change allows for awaiting the disposed plugin and added the
missing close method of the JavaScript transformer to the onDispose.
When the plugin is run multiple times on different projects/bundles
without proper closing it will result in a node heap corruption. This
allows us to cleanup the build before we start a new one.

Closes #31973

Author: Aukevanoost

packages/angular/build/src/private.ts

@@ -59,6 +59,7 @@ export function createCompilerPlugin(
     ),
   );
 }
+export { getSharedCompilationStateCleanup } from './tools/esbuild/angular/compilation-state';
 
 export type { AngularCompilation } from './tools/angular/compilation';
 export { DiagnosticModes } from './tools/angular/compilation';

packages/angular/build/src/tools/esbuild/angular/compilation-state.ts

@@ -10,6 +10,17 @@ export class SharedTSCompilationState {
   #pendingCompilation = true;
   #resolveCompilationReady: ((value: boolean) => void) | undefined;
   #compilationReadyPromise: Promise<boolean> | undefined;
+
+  /**
+   * ESbuild doesnt allow for awaiting the cleanup of plugins, therefore this
+   * allows consumers of the compiler-plugin to await the disposal of the plugin
+   * after ESbuild dispose function was called.
+   */
+  #disposeCompilation: (() => void) | undefined;
+  awaitCompilationDisposed: Promise<void> = new Promise((resolve) => {
+    this.#disposeCompilation = resolve;
+  });
+
   #hasErrors = true;
 
   get waitUntilReady(): Promise<boolean> {
@@ -37,6 +48,7 @@ export class SharedTSCompilationState {
 
   dispose(): void {
     this.markAsReady(true);
+    this.#disposeCompilation?.();
     globalSharedCompilationState = undefined;
   }
 }
@@ -46,3 +58,7 @@ let globalSharedCompilationState: SharedTSCompilationState | undefined;
 export function getSharedCompilationState(): SharedTSCompilationState {
   return (globalSharedCompilationState ??= new SharedTSCompilationState());
 }
+
+export function getSharedCompilationStateCleanup() {
+  return globalSharedCompilationState?.awaitCompilationDisposed ?? Promise.resolve();
+}

packages/angular/build/src/tools/esbuild/angular/compiler-plugin.ts

@@ -588,11 +588,14 @@ export function createCompilerPlugin(
         logCumulativeDurations();
       });
 
-      build.onDispose(() => {
-        sharedTSCompilationState?.dispose();
-        void compilation.close?.();
-        void cacheStore?.close();
-      });
+      build.onDispose(
+        () =>
+          void Promise.all(
+            [compilation?.close?.(), cacheStore?.close(), javascriptTransformer.close()].filter(
+              Boolean,
+            ),
+          ).then(() => sharedTSCompilationState?.dispose()),
+      );
 
       /**
        * Checks if the file has side-effects when `advancedOptimizations` is enabled.