feat(@angular-devkit/build-angular): support namedChunks option in application builder

This adds the support of `namedChunks` for the new `application` builder.
It generates output like the following:

```
Initial Chunk Files         | Names         |  Raw Size | Estimated Transfer Size
chunk-ACXUMF56.js           | -             |  94.14 kB |                28.25 kB
main-3WP5KDHR.js            | main          |  71.95 kB |                18.31 kB
polyfills-4UVFGIFL.js       | polyfills     |  32.85 kB |                10.68 kB
chunk-2XJVAMHT.js           | -             | 449 bytes |               449 bytes
styles-5INURTSO.css         | styles        |   0 bytes |                 0 bytes

                            | Initial Total | 199.38 kB |                57.68 kB

Lazy Chunk Files            | Names         |  Raw Size | Estimated Transfer Size
about.component-2PJOS5PM.js | -             | 401 bytes |               401 bytes
home.component-25UHFOEY.js  | -             | 398 bytes |               398 bytes
```

This is really handy to get a glimpse at what a chunk is referring to and be able to analyze it (especially in applications with dozens of chunks).

Author: cexbrayat

packages/angular_devkit/build_angular/src/builders/application/options.ts

@@ -237,6 +237,7 @@ export async function normalizeOptions(
     progress = true,
     externalPackages,
     deleteOutputPath,
+    namedChunks,
   } = options;
 
   // Return all the normalized options
@@ -284,6 +285,7 @@ export async function normalizeOptions(
     indexHtmlOptions,
     tailwindConfiguration,
     i18nOptions,
+    namedChunks,
   };
 }
 

packages/angular_devkit/build_angular/src/builders/application/schema.json

@@ -325,6 +325,11 @@
       "description": "Extract all licenses in a separate file.",
       "default": true
     },
+    "namedChunks": {
+      "type": "boolean",
+      "description": "Use file name for lazy loaded chunks.",
+      "default": false
+    },
     "subresourceIntegrity": {
       "type": "boolean",
       "description": "Enables the use of subresource integrity validation.",

packages/angular_devkit/build_angular/src/builders/application/tests/options/named-chunks_spec.ts

@@ -0,0 +1,70 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import { buildApplication } from '../../index';
+import { APPLICATION_BUILDER_INFO, BASE_OPTIONS, describeBuilder } from '../setup';
+
+const MAIN_OUTPUT = 'dist/main.js';
+const NAMED_LAZY_OUTPUT = 'dist/lazy-module-7QZXF7K7.js';
+const UNNAMED_LAZY_OUTPUT = 'dist/chunk-OW5RYMPM.js';
+
+describeBuilder(buildApplication, APPLICATION_BUILDER_INFO, (harness) => {
+  describe('Option: "namedChunks"', () => {
+    beforeEach(async () => {
+      // Setup a lazy loaded chunk
+      await harness.writeFiles({
+        'src/lazy-module.ts': 'export const value = 42;',
+        'src/main.ts': `import('./lazy-module');`,
+      });
+    });
+
+    it('generates named files in output when true', async () => {
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+        namedChunks: true,
+      });
+
+      const { result } = await harness.executeOnce();
+
+      expect(result?.success).toBe(true);
+
+      harness.expectFile(MAIN_OUTPUT).toExist();
+      harness.expectFile(NAMED_LAZY_OUTPUT).toExist();
+      harness.expectFile(UNNAMED_LAZY_OUTPUT).toNotExist();
+    });
+
+    it('does not generate named files in output when false', async () => {
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+        namedChunks: false,
+      });
+
+      const { result } = await harness.executeOnce();
+
+      expect(result?.success).toBe(true);
+
+      harness.expectFile(MAIN_OUTPUT).toExist();
+      harness.expectFile(NAMED_LAZY_OUTPUT).toNotExist();
+      harness.expectFile(UNNAMED_LAZY_OUTPUT).toExist();
+    });
+
+    it('does not generates named files in output when not present', async () => {
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+      });
+
+      const { result } = await harness.executeOnce();
+
+      expect(result?.success).toBe(true);
+
+      harness.expectFile(MAIN_OUTPUT).toExist();
+      harness.expectFile(NAMED_LAZY_OUTPUT).toNotExist();
+      harness.expectFile(UNNAMED_LAZY_OUTPUT).toExist();
+    });
+  });
+});

packages/angular_devkit/build_angular/src/builders/browser-esbuild/builder-status-warnings.ts

@@ -19,7 +19,6 @@ const UNSUPPORTED_OPTIONS: Array<keyof BrowserBuilderOptions> = [
   // 'commonChunk',
 
   // * Unused by builder and will be removed in a future release
-  'namedChunks',
   'vendorChunk',
   'resourcesOutputPath',
 
@@ -43,7 +42,6 @@ export function logBuilderStatusWarnings(options: BrowserBuilderOptions, context
     }
 
     if (
-      unsupportedOption === 'namedChunks' ||
       unsupportedOption === 'vendorChunk' ||
       unsupportedOption === 'resourcesOutputPath' ||
       unsupportedOption === 'deployUrl'

packages/angular_devkit/build_angular/src/tools/esbuild/application-code-bundle.ts

@@ -327,7 +327,7 @@ function getEsBuildCommonOptions(options: NormalizedApplicationBuildOptions): Bu
     outExtension: outExtension ? { '.js': `.${outExtension}` } : undefined,
     sourcemap: sourcemapOptions.scripts && (sourcemapOptions.hidden ? 'external' : true),
     splitting: true,
-    chunkNames: 'chunk-[hash]',
+    chunkNames: options.namedChunks ? '[name]-[hash]' : 'chunk-[hash]',
     tsconfig,
     external: externalDependencies,
     write: false,