test(@angular/build): add e2e test for animations chunk optimization

packages/angular/build/src/builders/application/chunk-optimizer.ts

@@ -312,6 +312,7 @@ export async function optimizeChunks(
       });
 
       const result = await bundle.generate({
+        compact: true,
         sourcemap,
         chunkFileNames: (chunkInfo) =>
           `${chunkInfo.name.replace(/-[a-zA-Z0-9]{8}$/, '')}-[hash].js`,

tests/e2e.bzl

@@ -59,6 +59,7 @@ WEBPACK_IGNORE_TESTS = [
     "tests/build/chunk-optimizer-lazy.js",
     "tests/build/chunk-optimizer-heuristic.js",
     "tests/build/chunk-optimizer-env.js",
+    "tests/build/chunk-optimizer-animations.js",
 ]
 
 def _to_glob(patterns):

tests/e2e/tests/build/chunk-optimizer-animations.ts

@@ -0,0 +1,74 @@
+import assert from 'node:assert/strict';
+import { readdir } from 'node:fs/promises';
+import { readFile, writeFile } from '../../utils/fs';
+import { installPackage } from '../../utils/packages';
+import { execWithEnv } from '../../utils/process';
+
+export default async function () {
+  // Read @angular/core version from test project's package.json
+  const projectJson = JSON.parse(await readFile('package.json'));
+  const ngCoreVersion =
+    projectJson.dependencies?.['@angular/core'] ??
+    projectJson.devDependencies?.['@angular/core'] ??
+    'latest';
+
+  // Install @angular/animations package with matching version
+  await installPackage(`@angular/animations@${ngCoreVersion}`);
+
+  // Configure app.config.ts with provideAnimationsAsync
+  const originalConfig = await readFile('src/app/app.config.ts');
+  await writeFile(
+    'src/app/app.config.ts',
+    `
+    import { provideAnimationsAsync } from '@angular/platform-browser/animations/async';
+    ${originalConfig.replace(/providers:\s*\[/, 'providers: [provideAnimationsAsync(),')}
+  `,
+  );
+
+  const updatedConfig = await readFile('src/app/app.config.ts');
+  assert.ok(
+    updatedConfig.includes('provideAnimationsAsync()'),
+    'Expected src/app/app.config.ts to include provideAnimationsAsync().',
+  );
+
+  // Build with chunk optimization
+  await execWithEnv('ng', ['build', '--output-hashing=none'], {
+    ...process.env,
+    NG_BUILD_OPTIMIZE_CHUNKS: '1',
+  });
+  const optimizedFiles = await readdir('dist/test-project/browser');
+  const optimizedJsFiles = optimizedFiles.filter((f) => f.endsWith('.js'));
+
+  // Read the optimized main.js file
+  const mainCode = await readFile('dist/test-project/browser/main.js');
+
+  // Check that optimized chunks still contain more than 1 javascript file
+  assert.ok(
+    optimizedJsFiles.length > 1,
+    `Expected more than one chunk, but found ${optimizedJsFiles.length}.`,
+  );
+
+  // Check that one of the lazy loaded chunks contains the animations package code
+  let foundAnimationsChunk = false;
+  for (const file of optimizedJsFiles) {
+    if (file === 'main.js') {
+      continue;
+    }
+    const code = await readFile(`dist/test-project/browser/${file}`);
+    if (code.includes('AnimationEngine')) {
+      foundAnimationsChunk = true;
+      break;
+    }
+  }
+
+  assert.ok(
+    foundAnimationsChunk,
+    'Expected to find AnimationEngine in one of the optimized lazy chunks.',
+  );
+
+  // The animations engine should not be bundled in main.js
+  assert.ok(
+    !mainCode.includes('AnimationEngine'),
+    'Expected main.js not to contain AnimationEngine from @angular/animations/browser.',
+  );
+}