fix(@angular-devkit/build-angular): provide an option to exclude specs in Karma builder

With this change we add an `exclude` option to the Karma builder to provide a way to exclude certain specs from the compilation.

This is useful, when having integration, e2e and unit tests with the same suffix.

Closes #24472

Author: alan-agius4

goldens/public-api/angular_devkit/build_angular/index.md

@@ -176,6 +176,7 @@ export interface KarmaBuilderOptions {
     browsers?: string;
     codeCoverage?: boolean;
     codeCoverageExclude?: string[];
+    exclude?: string[];
     fileReplacements?: FileReplacement_2[];
     include?: string[];
     inlineStyleLanguage?: InlineStyleLanguage_2;

packages/angular_devkit/build_angular/src/builders/karma/find-tests-plugin.ts

@@ -23,6 +23,7 @@ const PLUGIN_NAME = 'angular-find-tests-plugin';
 
 export interface FindTestsPluginOptions {
   include?: string[];
+  exclude?: string[];
   workspaceRoot: string;
   projectSourceRoot: string;
 }
@@ -33,7 +34,12 @@ export class FindTestsPlugin {
   constructor(private options: FindTestsPluginOptions) {}
 
   apply(compiler: Compiler): void {
-    const { include = ['**/*.spec.ts'], projectSourceRoot, workspaceRoot } = this.options;
+    const {
+      include = ['**/*.spec.ts'],
+      exclude = [],
+      projectSourceRoot,
+      workspaceRoot,
+    } = this.options;
     const webpackOptions = compiler.options;
     const entry =
       typeof webpackOptions.entry === 'function' ? webpackOptions.entry() : webpackOptions.entry;
@@ -42,7 +48,7 @@ export class FindTestsPlugin {
 
     // Add tests files are part of the entry-point.
     webpackOptions.entry = async () => {
-      const specFiles = await findTests(include, workspaceRoot, projectSourceRoot);
+      const specFiles = await findTests(include, exclude, workspaceRoot, projectSourceRoot);
 
       if (!specFiles.length) {
         assert(this.compilation, 'Compilation cannot be undefined.');
@@ -73,12 +79,13 @@ export class FindTestsPlugin {
 
 // go through all patterns and find unique list of files
 async function findTests(
-  patterns: string[],
+  include: string[],
+  exclude: string[],
   workspaceRoot: string,
   projectSourceRoot: string,
 ): Promise<string[]> {
-  const matchingTestsPromises = patterns.map((pattern) =>
-    findMatchingTests(pattern, workspaceRoot, projectSourceRoot),
+  const matchingTestsPromises = include.map((pattern) =>
+    findMatchingTests(pattern, exclude, workspaceRoot, projectSourceRoot),
   );
   const files = await Promise.all(matchingTestsPromises);
 
@@ -90,6 +97,7 @@ const normalizePath = (path: string): string => path.replace(/\\/g, '/');
 
 async function findMatchingTests(
   pattern: string,
+  ignore: string[],
   workspaceRoot: string,
   projectSourceRoot: string,
 ): Promise<string[]> {
@@ -132,7 +140,7 @@ async function findMatchingTests(
     root: projectSourceRoot,
     nomount: true,
     absolute: true,
-    ignore: ['**/node_modules/**'],
+    ignore: ['**/node_modules/**', ...ignore],
   });
 }
 

packages/angular_devkit/build_angular/src/builders/karma/index.ts

@@ -134,6 +134,7 @@ export function execute(
       webpackConfig.plugins.push(
         new FindTestsPlugin({
           include: options.include,
+          exclude: options.exclude,
           workspaceRoot: context.workspaceRoot,
           projectSourceRoot: path.join(context.workspaceRoot, sourceRoot),
         }),

packages/angular_devkit/build_angular/src/builders/karma/schema.json

@@ -141,7 +141,15 @@
         "type": "string"
       },
       "default": ["**/*.spec.ts"],
-      "description": "Globs of files to include, relative to workspace or project root. \nThere are 2 special cases:\n - when a path to directory is provided, all spec files ending \".spec.@(ts|tsx)\" will be included\n - when a path to a file is provided, and a matching spec file exists it will be included instead."
+      "description": "Globs of files to include, relative to project root. \nThere are 2 special cases:\n - when a path to directory is provided, all spec files ending \".spec.@(ts|tsx)\" will be included\n - when a path to a file is provided, and a matching spec file exists it will be included instead."
+    },
+    "exclude": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "default": [],
+      "description": "Globs of files to exclude, relative to the project root."
     },
     "sourceMap": {
       "description": "Output source maps for scripts and styles. For more information, see https://angular.io/guide/workspace-config#source-map-configuration.",

packages/angular_devkit/build_angular/src/builders/karma/tests/options/exclude_spec.ts

@@ -0,0 +1,44 @@
+/**
+ * @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.io/license
+ */
+
+import { execute } from '../../index';
+import { BASE_OPTIONS, KARMA_BUILDER_INFO, describeBuilder } from '../setup';
+
+describeBuilder(execute, KARMA_BUILDER_INFO, (harness) => {
+  describe('Option: "exclude"', () => {
+    beforeEach(async () => {
+      await harness.writeFiles({
+        'src/app/error.spec.ts': `
+        describe('Error spec', () => {
+          it('should error', () => {
+            expect(false).toBe(true);
+          });
+        });`,
+      });
+    });
+
+    it(`should not exclude any spec when exclude is not supplied`, async () => {
+      harness.useTarget('test', {
+        ...BASE_OPTIONS,
+      });
+
+      const { result } = await harness.executeOnce();
+      expect(result?.success).toBeFalse();
+    });
+
+    it(`should exclude spec that matches the 'exclude' pattern`, async () => {
+      harness.useTarget('test', {
+        ...BASE_OPTIONS,
+        exclude: ['**/error.spec.ts'],
+      });
+
+      const { result } = await harness.executeOnce();
+      expect(result?.success).toBeTrue();
+    });
+  });
+});