refactor(@angular/build): remove automatic addition of @angular/localize/init polyfill and related warnings

packages/angular/build/src/tools/esbuild/application-code-bundle.ts

@@ -444,14 +444,12 @@ function getEsBuildCommonPolyfillsOptions(
       namespace,
       cache: sourceFileCache?.loadResultCache,
       loadContent: async (_, build) => {
-        let hasLocalizePolyfill = false;
         let polyfillPaths = polyfills;
         let warnings: PartialMessage[] | undefined;
 
         if (tryToResolvePolyfillsAsRelative) {
           polyfillPaths = await Promise.all(
             polyfills.map(async (path) => {
-              hasLocalizePolyfill ||= path.startsWith('@angular/localize');
               if (path.startsWith('zone.js') || !extname(path)) {
                 return path;
               }
@@ -465,32 +463,6 @@ function getEsBuildCommonPolyfillsOptions(
               return result.path ? potentialPathRelative : path;
             }),
           );
-        } else {
-          hasLocalizePolyfill = polyfills.some((p) => p.startsWith('@angular/localize'));
-        }
-
-        // Add localize polyfill if needed.
-        // TODO: remove in version 19 or later.
-        if (!i18nOptions.shouldInline && !hasLocalizePolyfill) {
-          const result = await build.resolve('@angular/localize', {
-            kind: 'import-statement',
-            resolveDir: workspaceRoot,
-          });
-
-          if (result.path) {
-            polyfillPaths.push('@angular/localize/init');
-
-            (warnings ??= []).push({
-              text: 'Polyfill for "@angular/localize/init" was added automatically.',
-              notes: [
-                {
-                  text:
-                    'In the future, this functionality will be removed. ' +
-                    'Please add this polyfill in the "polyfills" section of your "angular.json" instead.',
-                },
-              ],
-            });
-          }
         }
 
         // Generate module contents with an import statement per defined polyfill

packages/schematics/angular/migrations/migration-collection.json

@@ -1,11 +1,16 @@
 {
   "schematics": {
     "use-application-builder": {
-      "version": "18.0.0",
+      "version": "19.0.0",
       "factory": "./use-application-builder/migration",
       "description": "Migrate application projects to the new build system. Application projects that are using the '@angular-devkit/build-angular' package's 'browser' and/or 'browser-esbuild' builders will be migrated to use the new 'application' builder. You can read more about this, including known issues and limitations, here: https://angular.dev/tools/cli/build-system-migration",
       "optional": true,
       "documentation": "tools/cli/build-system-migration"
+    },
+    "update-workspace-config": {
+      "version": "19.0.0",
+      "factory": "./update-workspace-config/migration",
+      "description": "Update the workspace configuration by replacing deprecated options in 'angular.json' for compatibility with the latest Angular CLI changes."
     }
   }
 }

packages/schematics/angular/migrations/update-workspace-config/migration.ts

@@ -0,0 +1,61 @@
+/**
+ * @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.dev/license
+ */
+
+import { Rule } from '@angular-devkit/schematics';
+import { allTargetOptions, updateWorkspace } from '../../utility/workspace';
+import { Builders, ProjectType } from '../../utility/workspace-models';
+
+/**
+ * Main entry point for the migration rule.
+ *
+ * This migration performs the following tasks:
+ * - Loops through all application projects in the workspace.
+ * - Identifies the build target for each application.
+ * - If the `localize` option is enabled but the polyfill `@angular/localize/init` is not present,
+ *   it adds the polyfill to the `polyfills` option of the build target.
+ *
+ * This migration is specifically for application projects that use either the `application` or `browser-esbuild` builders.
+ */
+export default function (): Rule {
+  return updateWorkspace((workspace) => {
+    for (const project of workspace.projects.values()) {
+      if (project.extensions.projectType !== ProjectType.Application) {
+        continue;
+      }
+
+      const buildTarget = project.targets.get('build');
+      if (
+        !buildTarget ||
+        (buildTarget.builder !== Builders.BuildApplication &&
+          buildTarget.builder !== Builders.Application &&
+          buildTarget.builder !== Builders.BrowserEsbuild)
+      ) {
+        continue;
+      }
+
+      const polyfills = buildTarget.options?.['polyfills'];
+      if (
+        Array.isArray(polyfills) &&
+        polyfills.some(
+          (polyfill) => typeof polyfill === 'string' && polyfill.startsWith('@angular/localize'),
+        )
+      ) {
+        // Skip the polyfill is already added
+        continue;
+      }
+
+      for (const [, options] of allTargetOptions(buildTarget, false)) {
+        if (options['localize']) {
+          buildTarget.options ??= {};
+          ((buildTarget.options['polyfills'] ??= []) as string[]).push('@angular/localize/init');
+          break;
+        }
+      }
+    }
+  });
+}

packages/schematics/angular/migrations/update-workspace-config/migration_spec.ts

@@ -0,0 +1,92 @@
+/**
+ * @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.dev/license
+ */
+
+import { EmptyTree } from '@angular-devkit/schematics';
+import { SchematicTestRunner, UnitTestTree } from '@angular-devkit/schematics/testing';
+import { ProjectType } from '../../utility/workspace-models';
+
+function createWorkSpaceConfig(tree: UnitTestTree) {
+  const angularConfig = {
+    version: 1,
+    projects: {
+      app: {
+        root: '/project/app',
+        sourceRoot: '/project/app/src',
+        projectType: ProjectType.Application,
+        prefix: 'app',
+        architect: {
+          build: {
+            builder: '@angular/build:application',
+            options: {
+              localize: true,
+              polyfills: [],
+            },
+          },
+        },
+      },
+    },
+  };
+
+  tree.create('/angular.json', JSON.stringify(angularConfig, undefined, 2));
+}
+
+describe(`Migration to update the workspace configuration`, () => {
+  const schematicName = 'update-workspace-config';
+  const schematicRunner = new SchematicTestRunner(
+    'migrations',
+    require.resolve('../migration-collection.json'),
+  );
+
+  let tree: UnitTestTree;
+  beforeEach(() => {
+    tree = new UnitTestTree(new EmptyTree());
+    createWorkSpaceConfig(tree);
+  });
+
+  it(`should add '@angular/localize/init' to polyfills if localize is enabled`, async () => {
+    const newTree = await schematicRunner.runSchematic(schematicName, {}, tree);
+    const {
+      projects: { app },
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    } = newTree.readJson('/angular.json') as any;
+
+    expect(app.architect.build.options.polyfills).toContain('@angular/localize/init');
+  });
+
+  it(`should not add '@angular/localize/init' to polyfills if it already exists`, async () => {
+    // Add '@angular/localize/init' manually
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const config = tree.readJson('/angular.json') as any;
+    config.projects.app.architect.build.options.polyfills.push('@angular/localize/init');
+    tree.overwrite('/angular.json', JSON.stringify(config, undefined, 2));
+
+    const newTree = await schematicRunner.runSchematic(schematicName, {}, tree);
+    const {
+      projects: { app },
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    } = newTree.readJson('/angular.json') as any;
+
+    const polyfills = app.architect.build.options.polyfills;
+    expect(polyfills.filter((p: string) => p === '@angular/localize/init').length).toBe(1);
+  });
+
+  it(`should not add polyfills if localize is not enabled`, async () => {
+    // Disable 'localize'
+    const config = JSON.parse(tree.readContent('/angular.json'));
+    config.projects.app.architect.build.options.localize = false;
+    tree.overwrite('/angular.json', JSON.stringify(config, undefined, 2));
+
+    const newTree = await schematicRunner.runSchematic(schematicName, {}, tree);
+    const {
+      projects: { app },
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    } = newTree.readJson('/angular.json') as any;
+
+    expect(app.architect.build.options.polyfills).not.toContain('@angular/localize/init');
+  });
+});