fix(@angular/build): do not reference sourcemaps in web workers and global stylesheet bundles when hidden setting is enabled

This commit addresses an issue where sourcemaps in web workers and global stylesheets were referenced despite the hidden setting being enabled.

Closes: #27833

Author: alan-agius4

packages/angular/build/src/builders/application/tests/options/sourcemap_spec.ts

@@ -124,6 +124,74 @@ describeBuilder(buildApplication, APPLICATION_BUILDER_INFO, (harness) => {
       harness.expectFile('dist/browser/main.js.map').content.toContain('/common/index.ts');
     });
 
+    it(`should not include 'sourceMappingURL' sourcemaps when hidden suboption is true`, async () => {
+      await harness.writeFile('src/styles.css', `div { flex: 1 }`);
+
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+        styles: ['src/styles.css'],
+        sourceMap: { scripts: true, styles: true, hidden: true },
+      });
+
+      const { result } = await harness.executeOnce();
+
+      expect(result?.success).toBeTrue();
+
+      harness.expectFile('dist/browser/main.js.map').toExist();
+      harness
+        .expectFile('dist/browser/main.js')
+        .content.not.toContain('sourceMappingURL=main.js.map');
+
+      harness.expectFile('dist/browser/styles.css.map').toExist();
+      harness
+        .expectFile('dist/browser/styles.css')
+        .content.not.toContain('sourceMappingURL=styles.css.map');
+    });
+
+    it(`should include 'sourceMappingURL' sourcemaps when hidden suboption is false`, async () => {
+      await harness.writeFile('src/styles.css', `div { flex: 1 }`);
+
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+        styles: ['src/styles.css'],
+        sourceMap: { scripts: true, styles: true, hidden: false },
+      });
+
+      const { result } = await harness.executeOnce();
+
+      expect(result?.success).toBeTrue();
+
+      harness.expectFile('dist/browser/main.js.map').toExist();
+      harness.expectFile('dist/browser/main.js').content.toContain('sourceMappingURL=main.js.map');
+
+      harness.expectFile('dist/browser/styles.css.map').toExist();
+      harness
+        .expectFile('dist/browser/styles.css')
+        .content.toContain('sourceMappingURL=styles.css.map');
+    });
+
+    it(`should include 'sourceMappingURL' sourcemaps when hidden suboption is not set`, async () => {
+      await harness.writeFile('src/styles.css', `div { flex: 1 }`);
+
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+        styles: ['src/styles.css'],
+        sourceMap: { scripts: true, styles: true },
+      });
+
+      const { result } = await harness.executeOnce();
+
+      expect(result?.success).toBeTrue();
+
+      harness.expectFile('dist/browser/main.js.map').toExist();
+      harness.expectFile('dist/browser/main.js').content.toContain('sourceMappingURL=main.js.map');
+
+      harness.expectFile('dist/browser/styles.css.map').toExist();
+      harness
+        .expectFile('dist/browser/styles.css')
+        .content.toContain('sourceMappingURL=styles.css.map');
+    });
+
     it('should add "x_google_ignoreList" extension to script sourcemap files when true', async () => {
       harness.useTarget('build', {
         ...BASE_OPTIONS,

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

@@ -36,7 +36,7 @@ import { setupJitPluginCallbacks } from './jit-plugin-callbacks';
 import { SourceFileCache } from './source-file-cache';
 
 export interface CompilerPluginOptions {
-  sourcemap: boolean;
+  sourcemap: boolean | 'external';
   tsconfig: string;
   jit?: boolean;
   /** Skip TypeScript compilation setup. This is useful to re-use the TypeScript compilation from another plugin. */
@@ -71,7 +71,12 @@ export function createCompilerPlugin(
         );
       }
       const javascriptTransformer = new JavaScriptTransformer(
-        pluginOptions,
+        {
+          sourcemap: !!pluginOptions.sourcemap,
+          thirdPartySourcemaps: pluginOptions.thirdPartySourcemaps,
+          advancedOptimizations: pluginOptions.advancedOptimizations,
+          jit: pluginOptions.jit,
+        },
         maxWorkers,
         cacheStore?.createCache('jstransformer'),
       );
@@ -541,8 +546,8 @@ function createCompilerOptionsTransformer(
     return {
       ...compilerOptions,
       noEmitOnError: false,
-      inlineSources: pluginOptions.sourcemap,
-      inlineSourceMap: pluginOptions.sourcemap,
+      inlineSources: !!pluginOptions.sourcemap,
+      inlineSourceMap: !!pluginOptions.sourcemap,
       mapRoot: undefined,
       sourceRoot: undefined,
       preserveSymlinks,

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

@@ -42,7 +42,7 @@ export function createCompilerPluginOptions(
   return {
     // JS/TS options
     pluginOptions: {
-      sourcemap: !!sourcemapOptions.scripts,
+      sourcemap: !!sourcemapOptions.scripts && (sourcemapOptions.hidden ? 'external' : true),
       thirdPartySourcemaps: sourcemapOptions.vendor,
       tsconfig,
       jit,

packages/angular/build/src/tools/esbuild/global-styles.ts

@@ -52,7 +52,7 @@ export function createGlobalStylesBundleOptions(
         workspaceRoot,
         optimization: !!optimizationOptions.styles.minify,
         inlineFonts: !!optimizationOptions.fonts.inline,
-        sourcemap: !!sourcemapOptions.styles,
+        sourcemap: !!sourcemapOptions.styles && (sourcemapOptions.hidden ? 'external' : true),
         preserveSymlinks,
         target,
         externalDependencies,