fix(@angular-devkit/build-angular): generate different content hashes for scripts which are changed during the optimization phase

Instead of generating the content hash based on the content of scripts BEFORE the optimization phase,
the content hash is generated AFTER the optimization phase.

Prevents caching issues where browsers block execution of scripts due to the integrity hash not matching
with the cached script in case of a script being optimized differently than in a previous build,
where it would previously result in the same content hash.

Fixes #22906

Author: martinfrancois

packages/angular_devkit/build_angular/src/webpack/plugins/scripts-webpack-plugin.ts

@@ -12,6 +12,11 @@ import { Chunk, Compilation, Compiler, sources as webpackSources } from 'webpack
 
 const Entrypoint = require('webpack/lib/Entrypoint');
 
+/**
+ * The name of the plugin provided to Webpack when tapping Webpack compiler hooks.
+ */
+const PLUGIN_NAME = 'scripts-webpack-plugin';
+
 export interface ScriptsWebpackPluginOptions {
   name: string;
   sourceMap?: boolean;
@@ -97,8 +102,8 @@ export class ScriptsWebpackPlugin {
       .filter((script) => !!script)
       .map((script) => path.resolve(this.options.basePath || '', script));
 
-    compiler.hooks.thisCompilation.tap('scripts-webpack-plugin', (compilation) => {
-      compilation.hooks.additionalAssets.tapPromise('scripts-webpack-plugin', async () => {
+    compiler.hooks.thisCompilation.tap(PLUGIN_NAME, (compilation) => {
+      compilation.hooks.additionalAssets.tapPromise(PLUGIN_NAME, async () => {
         if (await this.shouldSkip(compilation, scripts)) {
           if (this._cachedOutput) {
             this._insertOutput(compilation, this._cachedOutput, true);
@@ -149,19 +154,36 @@ export class ScriptsWebpackPlugin {
         });
 
         const combinedSource = new webpackSources.CachedSource(concatSource);
-        const filename = interpolateName(
-          { resourcePath: 'scripts.js' },
-          this.options.filename as string,
-          {
-            content: combinedSource.source(),
-          },
-        );
-
-        const output = { filename, source: combinedSource };
+
+        const output = { filename: this.options.filename, source: combinedSource };
         this._insertOutput(compilation, output);
         this._cachedOutput = output;
         addDependencies(compilation, scripts);
       });
+      compilation.hooks.processAssets.tapPromise(
+        {
+          name: PLUGIN_NAME,
+          stage: compiler.webpack.Compilation.PROCESS_ASSETS_STAGE_OPTIMIZE_HASH,
+          additionalAssets: true,
+        },
+        async (compilationAssets) => {
+          for (const assetName in compilationAssets) {
+            if (Object.prototype.hasOwnProperty.call(compilationAssets, assetName)) {
+              const asset = compilation.getAsset(assetName);
+              if (asset) {
+                const interpolatedFilename = interpolateName(
+                  { resourcePath: 'scripts.js' },
+                  assetName,
+                  { content: asset.source.source() },
+                );
+                if (assetName !== interpolatedFilename) {
+                  compilation.renameAsset(assetName, interpolatedFilename);
+                }
+              }
+            }
+          }
+        },
+      );
     });
   }
 }

tests/legacy-cli/e2e/tests/build/output-hashing.ts

@@ -1,12 +1,17 @@
 import { copyProjectAsset } from '../../utils/assets';
 import { expectFileMatchToExist, expectFileToMatch, writeMultipleFiles } from '../../utils/fs';
 import { ng } from '../../utils/process';
+import { updateJsonFile, updateTsConfig } from '../../utils/project';
 
 async function verifyMedia(fileNameRe: RegExp, content: RegExp) {
   const fileName = await expectFileMatchToExist('dist/test-project/', fileNameRe);
   await expectFileToMatch(`dist/test-project/${fileName}`, content);
 }
 
+async function getScriptsFilename(): Promise<string> {
+  return await expectFileMatchToExist('dist/test-project/', /external-module\.[0-9a-f]{16}\.js/);
+}
+
 export default async function () {
   await writeMultipleFiles({
     'src/styles.css': 'body { background-image: url("./assets/image.png"); }',
@@ -36,4 +41,40 @@ export default async function () {
   await expectFileToMatch('dist/test-project/index.html', /main\.[0-9a-f]{16}\.js/);
   await expectFileToMatch('dist/test-project/index.html', /styles\.[0-9a-f]{16}\.(css|js)/);
   await verifyMedia(/styles\.[0-9a-f]{16}\.(css|js)/, /image\.png/);
+
+  // verify content hash is based on code after optimizations
+  await writeMultipleFiles({
+    'src/script.js': 'try { console.log(); } catch {}',
+  });
+  await updateJsonFile('angular.json', (configJson) => {
+    const build = configJson.projects['test-project'].architect.build;
+    build.options['scripts'] = [
+      {
+        input: 'src/script.js',
+        inject: true,
+        bundleName: 'external-module',
+      },
+    ];
+    build.configurations['production'].outputHashing = 'all';
+    configJson['cli'] = { cache: { enabled: 'false' } };
+  });
+  await updateTsConfig((json) => {
+    json['compilerOptions']['target'] = 'es2017';
+    json['compilerOptions']['module'] = 'es2020';
+  });
+  await ng('build', '--configuration=production');
+  const filenameBuild1 = await getScriptsFilename();
+  await expectFileToMatch(`dist/test-project/${filenameBuild1}`, 'try{console.log()}catch(c){}');
+
+  await updateTsConfig((json) => {
+    json['compilerOptions']['target'] = 'es2019';
+  });
+  await ng('build', '--configuration=production');
+  const filenameBuild2 = await getScriptsFilename();
+  await expectFileToMatch(`dist/test-project/${filenameBuild2}`, 'try{console.log()}catch{}');
+  if (filenameBuild1 === filenameBuild2) {
+    throw new Error(
+      'Contents of the built file changed between builds, but the content hash stayed the same!',
+    );
+  }
 }