fix(@angular/build): include source map hashes in optimized chunk hashes

When `sourceMap.scripts` is enabled, `injectDebugIds` appends a
`//# debugId=<uuid>` comment derived from the chunk's source map content
to each emitted browser JS file after chunk optimization.

While esbuild includes source map content when computing output chunk
hashes, `optimizeChunks` strips the esbuild hash and relies on Rolldown
to compute `[hash]` for optimized chunks. Because Rolldown only hashed
the JS code and not the input source maps, a source change that only
altered the source map (such as adding or removing type definitions or
comments that shifted line numbers) changed the `debugId` bytes in the
emitted JS file and its SRI hash in `index.html` without changing the
chunk's filename.

Implement `augmentChunkHash` in the chunk optimizer's `angular-bundle`
plugin to include the input source map hashes when source maps are
enabled, and invalidate cached `BuildOutputFile` hashes when `contents`
are mutated.

Closes #34574

Author: alan-agius4

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

@@ -278,6 +278,21 @@ export async function optimizeChunks(
 
           return result;
         },
+        augmentChunkHash(chunk: { moduleIds: string[] }) {
+          if (!sourcemap) {
+            return;
+          }
+
+          let hash = '';
+          for (const id of chunk.moduleIds) {
+            const mapHash = maps[id]?.hash;
+            if (mapHash) {
+              hash += mapHash;
+            }
+          }
+
+          return hash || undefined;
+        },
       },
     ];
 

packages/angular/build/src/builders/application/tests/options/subresource-integrity_spec.ts

@@ -11,6 +11,7 @@ import { createHash } from 'node:crypto';
 import { readdirSync, readFileSync } from 'node:fs';
 import { join } from 'node:path';
 import { buildApplication } from '../../index';
+import { OutputHashing } from '../../schema';
 import {
   APPLICATION_BUILDER_INFO,
   BASE_OPTIONS,
@@ -254,5 +255,82 @@ describeBuilder(buildApplication, APPLICATION_BUILDER_INFO, (harness) => {
         /const scripts = \[\[(?:'[^']+', "module", false, false, "sha384-[^"]+", "anonymous"(?:, )?)+\]\];/,
       );
     });
+
+    it(`updates optimized chunk filename when source map changes cause debugId to change`, async () => {
+      await harness.writeFiles({
+        'src/app/shared-label.ts': `
+          export interface LabelInput {
+            text: string;
+          }
+          export function formatLabel(input: LabelInput): string {
+            return 'SHARED_LABEL:' + input.text;
+          }
+        `,
+        'src/app/lazy-a.ts': `
+          import { formatLabel } from './shared-label';
+          export const a = formatLabel({ text: 'a' });
+        `,
+        'src/app/lazy-b.ts': `
+          import { formatLabel } from './shared-label';
+          export const b = formatLabel({ text: 'b' });
+        `,
+        'src/app/lazy-c.ts': `
+          export const c = 'c';
+        `,
+        'src/main.ts': `
+          console.log(
+            import('./app/lazy-a'),
+            import('./app/lazy-b'),
+            import('./app/lazy-c'),
+          );
+        `,
+      });
+
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+        optimization: true,
+        outputHashing: OutputHashing.All,
+        sourceMap: { scripts: true },
+        subresourceIntegrity: true,
+      });
+
+      const firstBuild = await harness.executeOnce();
+      expect(firstBuild.result?.success).toBeTrue();
+
+      const distDir = workspacePath('dist/browser');
+      const findSharedChunk = () => {
+        const files = readdirSync(distDir).filter((f) => f.endsWith('.js'));
+        for (const file of files) {
+          const content = readFileSync(join(distDir, file), 'utf-8');
+          if (content.includes('SHARED_LABEL:')) {
+            return { file, content };
+          }
+        }
+        throw new Error('Shared label chunk not found');
+      };
+
+      const chunk1 = findSharedChunk();
+
+      // Make a type-only change that shifts line numbers in the source map without changing emitted JS code.
+      await harness.writeFile(
+        'src/app/shared-label.ts',
+        `
+          export interface LabelInput {
+            text: string;
+            extra?: number;
+          }
+          export function formatLabel(input: LabelInput): string {
+            return 'SHARED_LABEL:' + input.text;
+          }
+        `,
+      );
+
+      const secondBuild = await harness.executeOnce();
+      expect(secondBuild.result?.success).toBeTrue();
+
+      const chunk2 = findSharedChunk();
+      expect(chunk2.content).not.toBe(chunk1.content);
+      expect(chunk2.file).not.toBe(chunk1.file);
+    });
   });
 });

packages/angular/build/src/tools/esbuild/bundler-files.ts

@@ -104,6 +104,7 @@ export function createOutputFile(
       set contents(value: Uint8Array) {
         cachedContents = value;
         cachedText = null;
+        cachedHash = null;
       },
       get text(): string {
         cachedText ??= new TextDecoder('utf-8').decode(this.contents);
@@ -134,6 +135,7 @@ export function createOutputFile(
       set contents(value: Uint8Array) {
         cachedContents = value;
         cachedText = null;
+        cachedHash = null;
       },
       path,
       type,
@@ -160,6 +162,7 @@ export function createOutputFile(
 export function convertOutputFile(file: OutputFile, type: BuildOutputFileType): BuildOutputFile {
   let { contents: cachedContents } = file;
   let cachedText: string | null = null;
+  let cachedHash: string | null = file.hash;
 
   return {
     get contents(): Uint8Array {
@@ -168,8 +171,13 @@ export function convertOutputFile(file: OutputFile, type: BuildOutputFileType):
     set contents(value: Uint8Array) {
       cachedContents = value;
       cachedText = null;
+      cachedHash = null;
+    },
+    get hash(): string {
+      cachedHash ??= calculateHash(cachedContents);
+
+      return cachedHash;
     },
-    hash: file.hash,
     path: file.path,
     type,
     get size(): number {