fix(@angular/build): remove every output of a deleted asset in watch mode

packages/angular/build/src/builders/application/build-action.ts

@@ -314,11 +314,11 @@ function* emitOutputResults(
   }
 
   // Initially assume all previous assets files have been removed
-  const removedAssetFiles = new Map(previousAssetsInfo);
+  const removedAssetFiles = new Set(previousAssetsInfo);
   for (const { source, destination } of assetFiles) {
-    removedAssetFiles.delete(source);
+    removedAssetFiles.delete(destination);
 
-    if (!previousAssetsInfo.has(source)) {
+    if (!previousAssetsInfo.has(destination)) {
       incrementalResult.added.push(destination);
       incrementalResult.background = false;
     } else if (changes.modified.has(source)) {
@@ -353,7 +353,7 @@ function* emitOutputResults(
       path,
       type,
     })),
-    ...Array.from(removedAssetFiles.values(), (path) => ({
+    ...Array.from(removedAssetFiles, (path) => ({
       path,
       type: BuildOutputFileType.Browser,
     })),

packages/angular/build/src/builders/application/tests/behavior/rebuild-assets_spec.ts

@@ -76,5 +76,39 @@ describeBuilder(buildApplication, APPLICATION_BUILDER_INFO, (harness) => {
         },
       ]);
     });
+
+    it('remove all outputs of a deleted asset copied to multiple destinations', async () => {
+      harness.useTarget('build', {
+        ...BASE_OPTIONS,
+        assets: [
+          {
+            glob: '**/*',
+            input: 'public',
+          },
+          {
+            glob: '**/*',
+            input: 'public',
+            output: 'static',
+          },
+        ],
+        watch: true,
+      });
+
+      await harness.executeWithCases([
+        async ({ result }) => {
+          expect(result?.success).toBeTrue();
+          harness.expectFile('dist/browser/asset.txt').toExist();
+          harness.expectFile('dist/browser/static/asset.txt').toExist();
+
+          await harness.removeFile('public/asset.txt');
+        },
+
+        ({ result }) => {
+          expect(result?.success).toBeTrue();
+          harness.expectFile('dist/browser/asset.txt').toNotExist();
+          harness.expectFile('dist/browser/static/asset.txt').toNotExist();
+        },
+      ]);
+    });
   });
 });

packages/angular/build/src/tools/esbuild/bundler-execution-result.ts

@@ -31,7 +31,7 @@ export interface RebuildState {
     string,
     { hash: string; type: BuildOutputFileType; path: string }
   >;
-  previousAssetsInfo: ReadonlyMap<string, string>;
+  previousAssetsInfo: ReadonlySet<string>;
   templateUpdates?: Map<string, string>;
 }
 
@@ -176,9 +176,8 @@ export class ExecutionResult {
       previousOutputInfo: new Map(
         this.outputFiles.map(({ path, hash, type }) => [`${type}:${path}`, { hash, type, path }]),
       ),
-      previousAssetsInfo: new Map(
-        this.assetFiles.map(({ source, destination }) => [source, destination]),
-      ),
+      // Tracked by destination since one source can be copied to several outputs (e.g. per locale).
+      previousAssetsInfo: new Set(this.assetFiles.map(({ destination }) => destination)),
       templateUpdates: this.templateUpdates,
     };
   }