fix(@schematics/angular): support using default browser option when not present

The Angular schematics that require knowledge of the main entry point of
an application will now use the default value for the `application` builder.
The default value as per the `application` build system is `<project_source_root>/main.ts`.

Author: clydin

packages/schematics/angular/environments/index_spec.ts

@@ -50,7 +50,7 @@ describe('Environments Schematic', () => {
     build.builder = Builders.Browser;
     build.options = {
       ...build.options,
-      main: build.options.browser,
+      main: 'projects/foo/src/main.ts',
       browser: undefined,
     };
 

packages/schematics/angular/server/index_spec.ts

@@ -269,7 +269,7 @@ describe('Server Schematic', () => {
       build.builder = Builders.Browser;
       build.options = {
         ...build.options,
-        main: build.options.browser,
+        main: 'projects/bar/src/main.ts',
         browser: undefined,
       };
 

packages/schematics/angular/service-worker/index.ts

@@ -28,7 +28,7 @@ import { getAppModulePath, isStandaloneApp } from '../utility/ng-ast-utils';
 import { relativePathToWorkspaceRoot } from '../utility/paths';
 import { targetBuildNotFoundError } from '../utility/project-targets';
 import { findAppConfig } from '../utility/standalone/app_config';
-import { findBootstrapApplicationCall } from '../utility/standalone/util';
+import { findBootstrapApplicationCall, getMainFilePath } from '../utility/standalone/util';
 import { Builders } from '../utility/workspace-models';
 import { Schema as ServiceWorkerOptions } from './schema';
 
@@ -119,20 +119,18 @@ export default function (options: ServiceWorkerOptions): Rule {
     }
 
     const buildOptions = buildTarget.options as Record<string, string | boolean>;
-    let browserEntryPoint: string | undefined;
+    const browserEntryPoint = await getMainFilePath(host, options.project);
     const ngswConfigPath = join(normalize(project.root), 'ngsw-config.json');
 
     if (
       buildTarget.builder === Builders.Application ||
       buildTarget.builder === Builders.BuildApplication
     ) {
-      browserEntryPoint = buildOptions.browser as string;
       const productionConf = buildTarget.configurations?.production;
       if (productionConf) {
         productionConf.serviceWorker = ngswConfigPath;
       }
     } else {
-      browserEntryPoint = buildOptions.main as string;
       buildOptions.serviceWorker = true;
       buildOptions.ngswConfigPath = ngswConfigPath;
     }

packages/schematics/angular/service-worker/index_spec.ts

@@ -203,7 +203,7 @@ describe('Service Worker Schematic', () => {
       build.builder = Builders.Browser;
       build.options = {
         ...build.options,
-        main: build.options.browser,
+        main: 'projects/bar/src/main.ts',
         browser: undefined,
       };
 

packages/schematics/angular/ssr/index_spec.ts

@@ -182,7 +182,7 @@ describe('SSR Schematic', () => {
       build.builder = '@angular-devkit/build-angular:browser';
       build.options = {
         ...build.options,
-        main: build.options.browser,
+        main: 'projects/test-app/src/main.ts',
         browser: undefined,
       };
 

packages/schematics/angular/utility/standalone/util.ts

@@ -7,6 +7,7 @@
  */
 
 import { SchematicsException, Tree } from '@angular-devkit/schematics';
+import { join } from 'node:path/posix';
 import ts from '../../third_party/github.com/Microsoft/TypeScript/lib/typescript';
 import { Change, applyToUpdateRecorder } from '../change';
 import { targetBuildNotFoundError } from '../project-targets';
@@ -23,16 +24,23 @@ export async function getMainFilePath(tree: Tree, projectName: string): Promise<
   const project = workspace.projects.get(projectName);
   const buildTarget = project?.targets.get('build');
 
-  if (!buildTarget) {
+  if (!project || !buildTarget) {
     throw targetBuildNotFoundError();
   }
 
   const options = buildTarget.options as Record<string, string>;
 
-  return buildTarget.builder === Builders.Application ||
+  if (
+    buildTarget.builder === Builders.Application ||
     buildTarget.builder === Builders.BuildApplication
-    ? options.browser
-    : options.main;
+  ) {
+    // These builders support a default of `<project_source_root>/main.ts`
+    const projectSourceRoot = project.sourceRoot ?? join(project.root, 'src');
+
+    return options.browser ?? join(projectSourceRoot, 'main.ts');
+  }
+
+  return options.main;
 }
 
 /**