fix(@angular/build): allow a default application browser option

The application build system's `browser` option is now considered optional. If not present, the value will be an `main.ts` file within the configured project source root (`sourceRoot`). This change allows the removal of the `browser` option from any project that uses the default generated value.

Author: clydin

goldens/public-api/angular/build/index.api.md

@@ -25,7 +25,7 @@ export type ApplicationBuilderOptions = {
  appShell?: boolean;
  assets?: AssetPattern[];
  baseHref?: string;
- browser: string;
+ browser?: string;
  budgets?: Budget[];
  clearScreen?: boolean;
  conditions?: string[];

packages/angular/build/src/builders/application/options.ts

@@ -177,7 +177,12 @@ export async function normalizeOptions(
  i18nOptions.flatOutput = true;
  }
 
- const entryPoints = normalizeEntryPoints(workspaceRoot, options.browser, options.entryPoints);
+ const entryPoints = normalizeEntryPoints(
+ workspaceRoot,
+ projectSourceRoot,
+ options.browser,
+ options.entryPoints,
+ );
  const tsconfig = path.join(workspaceRoot, options.tsConfig);
  const optimizationOptions = normalizeOptimization(options.optimization);
  const sourcemapOptions = normalizeSourceMaps(options.sourceMap ?? false);
@@ -545,26 +550,25 @@ async function getTailwindConfig(
  */
 function normalizeEntryPoints(
  workspaceRoot: string,
+ projectSourceRoot: string,
  browser: string | undefined,
- entryPoints: Set<string> | Map<string, string> = new Set(),
+ entryPoints: Set<string> | Map<string, string> | undefined,
 ): Record<string, string> {
  if (browser === '') {
  throw new Error('`browser` option cannot be an empty string.');
  }
 
  // `browser` and `entryPoints` are mutually exclusive.
- if (browser && entryPoints.size > 0) {
+ if (browser && entryPoints) {
  throw new Error('Only one of `browser` or `entryPoints` may be provided.');
  }
- if (!browser && entryPoints.size === 0) {
- // Schema should normally reject this case, but programmatic usages of the builder might make this mistake.
- throw new Error('Either `browser` or at least one `entryPoints` value must be provided.');
- }
 
- // Schema types force `browser` to always be provided, but it may be omitted when the builder is invoked programmatically.
  if (browser) {
  // Use `browser` alone.
  return { 'main': path.join(workspaceRoot, browser) };
+ } else if (!entryPoints) {
+ // Default browser entry if no explicit entry points
+ return { 'main': path.join(projectSourceRoot, 'main.ts') };
  } else if (entryPoints instanceof Map) {
  return Object.fromEntries(
  Array.from(entryPoints.entries(), ([name, entryPoint]) => {

packages/angular/build/src/builders/application/schema.json

@@ -616,7 +616,7 @@
  }
  },
  "additionalProperties": false,
- "required": ["browser", "tsConfig"],
+ "required": ["tsConfig"],
  "definitions": {
  "assetPattern": {
  "oneOf": [

packages/angular/build/src/builders/application/tests/options/browser_spec.ts

@@ -42,6 +42,49 @@ describeBuilder(buildApplication, APPLICATION_BUILDER_INFO, (harness) => {
  harness.expectFile('dist/browser/main.js').content.toContain('console.log("main")');
  });
 
+ it('defaults to use `src/main.ts` if not present', async () => {
+ harness.useTarget('build', {
+ ...BASE_OPTIONS,
+ browser: undefined,
+ });
+
+ const { result } = await harness.executeOnce();
+
+ expect(result?.success).toBe(true);
+
+ harness.expectFile('dist/browser/main.js').toExist();
+ harness.expectFile('dist/browser/index.html').toExist();
+ });
+
+ it('uses project source root in default if `browser` not present', async () => {
+ harness.useProject('test', {
+ root: '.',
+ sourceRoot: 'source',
+ cli: {
+ cache: {
+ enabled: false,
+ },
+ },
+ });
+ harness.useTarget('build', {
+ ...BASE_OPTIONS,
+ browser: undefined,
+ index: false,
+ });
+
+ // Update app for a `source/main.ts` file based on the above changed `sourceRoot`
+ await harness.writeFile('source/main.ts', `console.log('main');`);
+ await harness.modifyFile('src/tsconfig.app.json', (content) =>
+ content.replace('main.ts', '../source/main.ts'),
+ );
+
+ const { result } = await harness.executeOnce();
+
+ expect(result?.success).toBe(true);
+
+ harness.expectFile('dist/browser/main.js').content.toContain('console.log("main")');
+ });
+
  it('fails and shows an error when file does not exist', async () => {
  harness.useTarget('build', {
  ...BASE_OPTIONS,