feat(@angular/build): add application builder karma testing to package

An `application` only variant of the `karma` builder found within the
`@angular-devkit/build-angular` package is now available within the
`@angular/build` package as `@angular/build:karma`. This builder will
only use the `application` builder found within `@angular/build` and
does not provide the `builderMode` option as `application` would be the
only valid value. Testing behavior is otherwise equivalent to using the
`@angular-devkit/build-angular:karma` builder with the `builderMode`
option set to `application`.

Author: clydin

.aspect/rules/external_repository_action_cache/npm_translate_lock_MzA5NzUwNzMx

@@ -4,7 +4,7 @@
 .npmrc=-1406867100
 modules/testing/builder/package.json=973445093
 package.json=551629798
-packages/angular/build/package.json=1444505662
+packages/angular/build/package.json=-450547974
 packages/angular/cli/package.json=-803141029
 packages/angular/pwa/package.json=1108903917
 packages/angular/ssr/package.json=1856194341

packages/angular/build/BUILD.bazel

@@ -24,6 +24,11 @@ ts_json_schema(
     src = "src/builders/extract-i18n/schema.json",
 )
 
+ts_json_schema(
+    name = "ng_karma_schema",
+    src = "src/builders/karma/schema.json",
+)
+
 ts_json_schema(
     name = "ng_packagr_schema",
     src = "src/builders/ng-packagr/schema.json",
@@ -63,6 +68,7 @@ ts_project(
         "//packages/angular/build:src/builders/application/schema.ts",
         "//packages/angular/build:src/builders/dev-server/schema.ts",
         "//packages/angular/build:src/builders/extract-i18n/schema.ts",
+        "//packages/angular/build:src/builders/karma/schema.ts",
         "//packages/angular/build:src/builders/ng-packagr/schema.ts",
     ],
     data = RUNTIME_ASSETS,
@@ -85,6 +91,7 @@ ts_project(
         "//:node_modules/@babel/plugin-syntax-import-attributes",
         "//:node_modules/@inquirer/confirm",
         "//:node_modules/@types/babel__core",
+        "//:node_modules/@types/karma",
         "//:node_modules/@types/less",
         "//:node_modules/@types/node",
         "//:node_modules/@types/picomatch",
@@ -99,6 +106,7 @@ ts_project(
         "//:node_modules/https-proxy-agent",
         "//:node_modules/istanbul-lib-instrument",
         "//:node_modules/jsonc-parser",
+        "//:node_modules/karma",
         "//:node_modules/less",
         "//:node_modules/listr2",
         "//:node_modules/lmdb",
@@ -200,6 +208,39 @@ ts_project(
     ],
 )
 
+ts_project(
+    name = "karma_integration_test_lib",
+    testonly = True,
+    srcs = glob(include = ["src/builders/karma/tests/**/*.ts"]),
+    deps = [
+        ":build_rjs",
+        "//packages/angular/build/private:private_rjs",
+        "//modules/testing/builder:builder_rjs",
+        ":node_modules/@angular-devkit/architect",
+
+        # karma specific test deps
+        "//:node_modules/karma-chrome-launcher",
+        "//:node_modules/karma-coverage",
+        "//:node_modules/karma-jasmine",
+        "//:node_modules/karma-jasmine-html-reporter",
+        "//:node_modules/puppeteer",
+
+        # Base dependencies for the karma in hello-world-app.
+        "//:node_modules/@angular/common",
+        "//:node_modules/@angular/compiler",
+        "//:node_modules/@angular/compiler-cli",
+        "//:node_modules/@angular/core",
+        "//:node_modules/@angular/platform-browser",
+        "//:node_modules/@angular/platform-browser-dynamic",
+        "//:node_modules/@angular/router",
+        "//:node_modules/rxjs",
+        "//:node_modules/tslib",
+        "//:node_modules/typescript",
+        "//:node_modules/zone.js",
+        "//:node_modules/buffer",
+    ],
+)
+
 jasmine_test(
     name = "application_integration_tests",
     size = "large",
@@ -216,6 +257,19 @@ jasmine_test(
     shard_count = 10,
 )
 
+jasmine_test(
+    name = "karma_integration_tests",
+    size = "large",
+    data = [":karma_integration_test_lib_rjs"],
+    env = {
+        # TODO: Replace Puppeteer downloaded browsers with Bazel-managed browsers,
+        # or standardize to avoid complex configuration like this!
+        "PUPPETEER_DOWNLOAD_PATH": "../../../node_modules/puppeteer/downloads",
+    },
+    flaky = True,
+    shard_count = 10,
+)
+
 genrule(
     name = "license",
     srcs = ["//:LICENSE"],

packages/angular/build/builders.json

@@ -15,6 +15,11 @@
       "schema": "./src/builders/extract-i18n/schema.json",
       "description": "Extract i18n messages from an application."
     },
+    "karma": {
+      "implementation": "./src/builders/karma",
+      "schema": "./src/builders/karma/schema.json",
+      "description": "Run Karma unit tests."
+    },
     "ng-packagr": {
       "implementation": "./src/builders/ng-packagr/index",
       "schema": "./src/builders/ng-packagr/schema.json",

packages/angular/build/package.json

@@ -58,6 +58,7 @@
     "@angular/platform-server": "0.0.0-ANGULAR-FW-PEER-DEP",
     "@angular/service-worker": "0.0.0-ANGULAR-FW-PEER-DEP",
     "@angular/ssr": "^0.0.0-PLACEHOLDER",
+    "karma": "^6.4.0",
     "less": "^4.2.0",
     "ng-packagr": "0.0.0-NG-PACKAGR-PEER-DEP",
     "postcss": "^8.4.0",
@@ -77,6 +78,9 @@
     "@angular/ssr": {
       "optional": true
     },
+    "karma": {
+      "optional": true
+    },
     "less": {
       "optional": true
     },

packages/angular_devkit/build_angular/src/builders/karma/application_builder.ts renamed to packages/angular/build/src/builders/karma/application_builder.ts

@@ -6,7 +6,6 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { BuildOutputFileType } from '@angular/build';
 import {
   ApplicationBuilderInternalOptions,
   Result,
@@ -15,20 +14,22 @@ import {
   buildApplicationInternal,
   emitFilesToDisk,
 } from '@angular/build/private';
-import { BuilderContext, BuilderOutput } from '@angular-devkit/architect';
-import { randomUUID } from 'crypto';
+import type { BuilderContext, BuilderOutput } from '@angular-devkit/architect';
 import glob from 'fast-glob';
-import * as fs from 'fs/promises';
-import { IncomingMessage, ServerResponse } from 'http';
-import type { Config, ConfigOptions, FilePattern, InlinePluginDef } from 'karma';
-import * as path from 'path';
-import { Observable, Subscriber, catchError, defaultIfEmpty, from, of, switchMap } from 'rxjs';
-import { Configuration } from 'webpack';
-import { ExecutionTransformer } from '../../transforms';
-import { OutputHashing } from '../browser-esbuild/schema';
+import type { Config, ConfigOptions, FilePattern, InlinePluginDef, Server } from 'karma';
+import { randomUUID } from 'node:crypto';
+import * as fs from 'node:fs/promises';
+import type { IncomingMessage, ServerResponse } from 'node:http';
+import { createRequire } from 'node:module';
+import * as path from 'node:path';
+import { ReadableStreamController } from 'node:stream/web';
+import { BuildOutputFileType } from '../../tools/esbuild/bundler-context';
+import { OutputHashing } from '../application/schema';
 import { findTests, getTestEntrypoints } from './find-tests';
 import { Schema as KarmaBuilderOptions } from './schema';
 
+const localResolve = createRequire(__filename).resolve;
+
 interface BuildOptions extends ApplicationBuilderInternalOptions {
   // We know that it's always a string since we set it.
   outputPath: string;
@@ -170,7 +171,7 @@ function injectKarmaReporter(
   buildOptions: BuildOptions,
   buildIterator: AsyncIterator<Result>,
   karmaConfig: Config & ConfigOptions,
-  subscriber: Subscriber<BuilderOutput>,
+  controller: ReadableStreamController<BuilderOutput>,
 ) {
   const reporterName = 'angular-progress-notifier';
 
@@ -204,7 +205,7 @@ function injectKarmaReporter(
           }
 
           if (buildOutput.kind === ResultKind.Failure) {
-            subscriber.next({ success: false, message: 'Build failed' });
+            controller.enqueue({ success: false, message: 'Build failed' });
           } else if (
             buildOutput.kind === ResultKind.Incremental ||
             buildOutput.kind === ResultKind.Full
@@ -226,9 +227,9 @@ function injectKarmaReporter(
 
     onRunComplete = function (_browsers: unknown, results: RunCompleteInfo) {
       if (results.exitCode === 0) {
-        subscriber.next({ success: true });
+        controller.enqueue({ success: true });
       } else {
-        subscriber.next({ success: false });
+        controller.enqueue({ success: false });
       }
     };
   }
@@ -254,44 +255,48 @@ export function execute(
   context: BuilderContext,
   karmaOptions: ConfigOptions,
   transforms: {
-    webpackConfiguration?: ExecutionTransformer<Configuration>;
     // The karma options transform cannot be async without a refactor of the builder implementation
     karmaOptions?: (options: ConfigOptions) => ConfigOptions;
   } = {},
-): Observable<BuilderOutput> {
-  return from(initializeApplication(options, context, karmaOptions, transforms)).pipe(
-    switchMap(
-      ([karma, karmaConfig, buildOptions, buildIterator]) =>
-        new Observable<BuilderOutput>((subscriber) => {
-          // If `--watch` is explicitly enabled or if we are keeping the Karma
-          // process running, we should hook Karma into the build.
-          if (buildIterator) {
-            injectKarmaReporter(buildOptions, buildIterator, karmaConfig, subscriber);
-          }
+): AsyncIterable<BuilderOutput> {
+  let karmaServer: Server;
+
+  return new ReadableStream({
+    async start(controller) {
+      let init;
+      try {
+        init = await initializeApplication(options, context, karmaOptions, transforms);
+      } catch (err) {
+        if (err instanceof ApplicationBuildError) {
+          controller.enqueue({ success: false, message: err.message });
+          controller.close();
+
+          return;
+        }
 
-          // Complete the observable once the Karma server returns.
-          const karmaServer = new karma.Server(karmaConfig as Config, (exitCode) => {
-            subscriber.next({ success: exitCode === 0 });
-            subscriber.complete();
-          });
+        throw err;
+      }
+
+      const [karma, karmaConfig, buildOptions, buildIterator] = init;
 
-          const karmaStart = karmaServer.start();
-
-          // Cleanup, signal Karma to exit.
-          return () => {
-            void karmaStart.then(() => karmaServer.stop());
-          };
-        }),
-    ),
-    catchError((err) => {
-      if (err instanceof ApplicationBuildError) {
-        return of({ success: false, message: err.message });
+      // If `--watch` is explicitly enabled or if we are keeping the Karma
+      // process running, we should hook Karma into the build.
+      if (buildIterator) {
+        injectKarmaReporter(buildOptions, buildIterator, karmaConfig, controller);
       }
 
-      throw err;
-    }),
-    defaultIfEmpty({ success: false }),
-  );
+      // Close the stream once the Karma server returns.
+      karmaServer = new karma.Server(karmaConfig as Config, (exitCode) => {
+        controller.enqueue({ success: exitCode === 0 });
+        controller.close();
+      });
+
+      await karmaServer.start();
+    },
+    async cancel() {
+      await karmaServer?.stop();
+    },
+  });
 }
 
 async function getProjectSourceRoot(context: BuilderContext): Promise<string> {
@@ -314,10 +319,8 @@ function normalizePolyfills(polyfills: string | string[] | undefined): [string[]
     polyfills = [];
   }
 
-  const jasmineGlobalEntryPoint =
-    '@angular-devkit/build-angular/src/builders/karma/jasmine_global.js';
-  const jasmineGlobalCleanupEntrypoint =
-    '@angular-devkit/build-angular/src/builders/karma/jasmine_global_cleanup.js';
+  const jasmineGlobalEntryPoint = localResolve('./polyfills/jasmine_global.js');
+  const jasmineGlobalCleanupEntrypoint = localResolve('./polyfills/jasmine_global_cleanup.js');
 
   const zoneTestingEntryPoint = 'zone.js/testing';
   const polyfillsExludingZoneTesting = polyfills.filter((p) => p !== zoneTestingEntryPoint);
@@ -351,18 +354,11 @@ async function initializeApplication(
   context: BuilderContext,
   karmaOptions: ConfigOptions,
   transforms: {
-    webpackConfiguration?: ExecutionTransformer<Configuration>;
     karmaOptions?: (options: ConfigOptions) => ConfigOptions;
   } = {},
 ): Promise<
   [typeof import('karma'), Config & ConfigOptions, BuildOptions, AsyncIterator<Result> | null]
 > {
-  if (transforms.webpackConfiguration) {
-    context.logger.warn(
-      `This build is using the application builder but transforms.webpackConfiguration was provided. The transform will be ignored.`,
-    );
-  }
-
   const outputPath = path.join(context.workspaceRoot, 'dist/test-out', randomUUID());
   const projectSourceRoot = await getProjectSourceRoot(context);
 
@@ -376,7 +372,7 @@ async function initializeApplication(
   if (options.main) {
     entryPoints.set(mainName, options.main);
   } else {
-    entryPoints.set(mainName, '@angular-devkit/build-angular/src/builders/karma/init_test_bed.js');
+    entryPoints.set(mainName, localResolve('./polyfills/init_test_bed.js'));
   }
 
   const instrumentForCoverage = options.codeCoverage