feat(@angular-devkit/build-angular): option to build and test only specified spec files

packages/angular_devkit/build_angular/src/angular-cli-files/plugins/single-test-transform.ts

@@ -0,0 +1,58 @@
+/**
+ * @license
+ * Copyright Google Inc. 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 { logging } from '@angular-devkit/core';
+import { getOptions } from 'loader-utils';
+import { extname, join } from 'path';
+import { loader } from 'webpack';
+
+export interface SingleTestTransformLoaderOptions {
+  files: string[]; // list of paths relative to main
+  logger: logging.Logger;
+}
+
+export const SingleTestTransformLoader = require.resolve(join(__dirname, 'single-test-transform'));
+
+/**
+ * This loader transforms the default test file to only run tests
+ * for some specs instead of all specs.
+ * It works by replacing the known content of the auto-generated test file:
+ *   const context = require.context('./', true, /\.spec\.ts$/);
+ *   context.keys().map(context);
+ * with:
+ *   const context = { keys: () => ({ map: (_a) => { } }) };
+ *   context.keys().map(context);
+ * So that it does nothing.
+ * Then it adds import statements for each file in the files options
+ * array to import them directly, and thus run the tests there.
+ */
+export default function loader(this: loader.LoaderContext, source: string) {
+  const options = getOptions(this) as SingleTestTransformLoaderOptions;
+  const lineSeparator = process.platform === 'win32' ? '\r\n' : '\n';
+
+  const targettedImports = options.files
+    .map(path => `require('./${path.replace('.' + extname(path), '')}');`)
+    .join(lineSeparator);
+
+  // TODO: maybe a documented 'marker/comment' inside test.ts would be nicer?
+  const regex = /require\.context\(.*/;
+
+  // signal the user that expected content is not present
+  if (!regex.test(source)) {
+    const message = [
+      `The 'include' option requires that the 'main' file for tests include the line below:`,
+      `const context = require.context('./', true, /\.spec\.ts$/);`,
+      `Arguments passed to require.context are not strict and can be changed`,
+    ];
+    options.logger.error(message.join(lineSeparator));
+  }
+
+  const mockedRequireContext = '{ keys: () => ({ map: (_a) => { } }) };' + lineSeparator;
+  source = source.replace(regex, mockedRequireContext + targettedImports);
+
+  return source;
+}

packages/angular_devkit/build_angular/src/angular-cli-files/utilities/find-tests.ts

@@ -0,0 +1,62 @@
+/**
+ * @license
+ * Copyright Google Inc. 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 { existsSync } from 'fs';
+import * as glob from 'glob';
+import { basename, dirname, extname, join } from 'path';
+import { isDirectory } from './is-directory';
+
+// go through all patterns and find unique list of files
+export function findTests(patterns: string[], cwd: string, workspaceRoot: string): string[] {
+  return patterns.reduce(
+    (files, pattern) => {
+      const relativePathToMain = cwd.replace(workspaceRoot, '').substr(1); // remove leading slash
+      const tests = findMatchingTests(pattern, cwd, relativePathToMain);
+      tests.forEach(file => {
+        if (!files.includes(file)) {
+          files.push(file);
+        }
+      });
+
+      return files;
+    },
+    [] as string[],
+  );
+}
+
+function findMatchingTests(pattern: string, cwd: string, relativePathToMain: string): string[] {
+  // normalize pattern, glob lib only accepts forward slashes
+  pattern = pattern.replace(/\\/g, '/');
+  relativePathToMain = relativePathToMain.replace(/\\/g, '/');
+
+  // remove relativePathToMain to support relative paths from root
+  // such paths are easy to get when running scripts via IDEs
+  if (pattern.startsWith(relativePathToMain + '/')) {
+    pattern = pattern.substr(relativePathToMain.length + 1); // +1 to include slash
+  }
+
+  // special logic when pattern does not look like a glob
+  if (!glob.hasMagic(pattern)) {
+    if (isDirectory(join(cwd, pattern))) {
+      pattern = `${pattern}/**/*.spec.@(ts|tsx)`;
+    } else {
+      // see if matching spec file exists
+      const extension = extname(pattern);
+      const matchingSpec = `${basename(pattern, extension)}.spec${extension}`;
+
+      if (existsSync(join(cwd, dirname(pattern), matchingSpec))) {
+        pattern = join(dirname(pattern), matchingSpec).replace(/\\/g, '/');
+      }
+    }
+  }
+
+  const files = glob.sync(pattern, {
+    cwd,
+  });
+
+  return files;
+}

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

@@ -6,7 +6,8 @@
  * found in the LICENSE file at https://angular.io/license
  */
 import { BuilderContext, BuilderOutput, createBuilder } from '@angular-devkit/architect';
-import { resolve } from 'path';
+import { experimental, getSystemPath, join } from '@angular-devkit/core';
+import { dirname, resolve } from 'path';
 import { Observable, from } from 'rxjs';
 import { defaultIfEmpty, switchMap } from 'rxjs/operators';
 import * as webpack from 'webpack';
@@ -17,14 +18,19 @@ import {
   getTestConfig,
   getWorkerConfig,
 } from '../angular-cli-files/models/webpack-configs';
+import {
+  SingleTestTransformLoader,
+  SingleTestTransformLoaderOptions,
+} from '../angular-cli-files/plugins/single-test-transform';
+import { findTests } from '../angular-cli-files/utilities/find-tests';
 import { Schema as BrowserBuilderOptions } from '../browser/schema';
 import { ExecutionTransformer } from '../transforms';
 import { assertCompatibleAngularVersion } from '../utils/version';
 import { generateBrowserWebpackConfigFromContext } from '../utils/webpack-browser-config';
 import { Schema as KarmaBuilderOptions } from './schema';
 
 // tslint:disable-next-line:no-implicit-dependencies
-export type KarmaConfigOptions = import ('karma').ConfigOptions & {
+export type KarmaConfigOptions = import('karma').ConfigOptions & {
   buildWebpack?: unknown;
   configFile?: string;
 };
@@ -34,12 +40,12 @@ async function initialize(
   context: BuilderContext,
   webpackConfigurationTransformer?: ExecutionTransformer<webpack.Configuration>,
   // tslint:disable-next-line:no-implicit-dependencies
-): Promise<[typeof import ('karma'), webpack.Configuration]> {
-  const { config } = await generateBrowserWebpackConfigFromContext(
+): Promise<[experimental.workspace.Workspace, typeof import('karma'), webpack.Configuration]> {
+  const { config, workspace } = await generateBrowserWebpackConfigFromContext(
     // only two properties are missing:
     // * `outputPath` which is fixed for tests
     // * `budgets` which might be incorrect due to extra dev libs
-    { ...options as unknown as BrowserBuilderOptions, outputPath: '', budgets: undefined },
+    { ...((options as unknown) as BrowserBuilderOptions), outputPath: '', budgets: undefined },
     context,
     wco => [
       getCommonConfig(wco),
@@ -54,6 +60,7 @@ async function initialize(
   const karma = await import('karma');
 
   return [
+    workspace,
     karma,
     webpackConfigurationTransformer ? await webpackConfigurationTransformer(config[0]) : config[0],
   ];
@@ -63,71 +70,110 @@ export function execute(
   options: KarmaBuilderOptions,
   context: BuilderContext,
   transforms: {
-    webpackConfiguration?: ExecutionTransformer<webpack.Configuration>,
+    webpackConfiguration?: ExecutionTransformer<webpack.Configuration>;
     // The karma options transform cannot be async without a refactor of the builder implementation
-    karmaOptions?: (options: KarmaConfigOptions) => KarmaConfigOptions,
+    karmaOptions?: (options: KarmaConfigOptions) => KarmaConfigOptions;
   } = {},
 ): Observable<BuilderOutput> {
   // Check Angular version.
   assertCompatibleAngularVersion(context.workspaceRoot, context.logger);
 
   return from(initialize(options, context, transforms.webpackConfiguration)).pipe(
-    switchMap(([karma, webpackConfig]) => new Observable<BuilderOutput>(subscriber => {
-      const karmaOptions: KarmaConfigOptions = {};
-
-      if (options.watch !== undefined) {
-        karmaOptions.singleRun = !options.watch;
-      }
-
-      // Convert browsers from a string to an array
-      if (options.browsers) {
-        karmaOptions.browsers = options.browsers.split(',');
-      }
-
-      if (options.reporters) {
-        // Split along commas to make it more natural, and remove empty strings.
-        const reporters = options.reporters
-          .reduce<string[]>((acc, curr) => acc.concat(curr.split(',')), [])
-          .filter(x => !!x);
-
-        if (reporters.length > 0) {
-          karmaOptions.reporters = reporters;
-        }
-      }
-
-      // Assign additional karmaConfig options to the local ngapp config
-      karmaOptions.configFile = resolve(context.workspaceRoot, options.karmaConfig);
-
-      karmaOptions.buildWebpack = {
-        options,
-        webpackConfig,
-        // Pass onto Karma to emit BuildEvents.
-        successCb: () => subscriber.next({ success: true }),
-        failureCb: () => subscriber.next({ success: false }),
-        // Workaround for https://github.com/karma-runner/karma/issues/3154
-        // When this workaround is removed, user projects need to be updated to use a Karma
-        // version that has a fix for this issue.
-        toJSON: () => { },
-        logger: context.logger,
-      };
-
-      // Complete the observable once the Karma server returns.
-      const karmaServer = new karma.Server(
-        transforms.karmaOptions ? transforms.karmaOptions(karmaOptions) : karmaOptions,
-        () => subscriber.complete());
-      // karma typings incorrectly define start's return value as void
-      // tslint:disable-next-line:no-use-of-empty-return-value
-      const karmaStart = karmaServer.start() as unknown as Promise<void>;
-
-      // Cleanup, signal Karma to exit.
-      return () => {
-        // Karma only has the `stop` method start with 3.1.1, so we must defensively check.
-        const karmaServerWithStop = karmaServer as unknown as { stop: () => Promise<void> };
-        if (typeof karmaServerWithStop.stop === 'function') {
-          return karmaStart.then(() => karmaServerWithStop.stop());
-        }
-      };
-    })),
+    switchMap(
+      ([workspace, karma, webpackConfig]) =>
+        new Observable<BuilderOutput>(subscriber => {
+          const karmaOptions: KarmaConfigOptions = {};
+
+          if (options.watch !== undefined) {
+            karmaOptions.singleRun = !options.watch;
+          }
+
+          // Convert browsers from a string to an array
+          if (options.browsers) {
+            karmaOptions.browsers = options.browsers.split(',');
+          }
+
+          if (options.reporters) {
+            // Split along commas to make it more natural, and remove empty strings.
+            const reporters = options.reporters
+              .reduce<string[]>((acc, curr) => acc.concat(curr.split(',')), [])
+              .filter(x => !!x);
+
+            if (reporters.length > 0) {
+              karmaOptions.reporters = reporters;
+            }
+          }
+
+          // prepend special webpack loader that will transform test.ts
+          if (
+            webpackConfig &&
+            webpackConfig.module &&
+            options.include &&
+            options.include.length > 0
+          ) {
+            const mainFilePath = getSystemPath(join(workspace.root, options.main));
+            const files = findTests(
+              options.include,
+              dirname(mainFilePath),
+              getSystemPath(workspace.root),
+            );
+            // early exit, no reason to start karma
+            if (!files.length) {
+              subscriber.error(
+                `Specified patterns: "${options.include.join(', ')}" did not match any spec files`,
+              );
+
+              return;
+            }
+
+            webpackConfig.module.rules.unshift({
+              test: path => path === mainFilePath,
+              use: {
+                // cannot be a simple path as it differs between environments
+                loader: SingleTestTransformLoader,
+                options: {
+                  files,
+                  logger: context.logger,
+                } as SingleTestTransformLoaderOptions,
+              },
+            });
+          }
+
+          // Assign additional karmaConfig options to the local ngapp config
+          karmaOptions.configFile = resolve(context.workspaceRoot, options.karmaConfig);
+
+          karmaOptions.buildWebpack = {
+            options,
+            webpackConfig,
+            // Pass onto Karma to emit BuildEvents.
+            successCb: () => subscriber.next({ success: true }),
+            failureCb: () => subscriber.next({ success: false }),
+            // Workaround for https://github.com/karma-runner/karma/issues/3154
+            // When this workaround is removed, user projects need to be updated to use a Karma
+            // version that has a fix for this issue.
+            toJSON: () => {},
+            logger: context.logger,
+          };
+
+          // Complete the observable once the Karma server returns.
+          const karmaServer = new karma.Server(
+            transforms.karmaOptions ? transforms.karmaOptions(karmaOptions) : karmaOptions,
+            () => subscriber.complete(),
+          );
+          // karma typings incorrectly define start's return value as void
+          // tslint:disable-next-line:no-use-of-empty-return-value
+          const karmaStart = (karmaServer.start() as unknown) as Promise<void>;
+
+          // Cleanup, signal Karma to exit.
+          return () => {
+            // Karma only has the `stop` method start with 3.1.1, so we must defensively check.
+            const karmaServerWithStop = (karmaServer as unknown) as { stop: () => Promise<void> };
+            if (typeof karmaServerWithStop.stop === 'function') {
+              return karmaStart.then(() => karmaServerWithStop.stop());
+            }
+          };
+        }),
+    ),
     defaultIfEmpty({ success: false }),
   );
 }

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

@@ -63,6 +63,13 @@
       "type": "string",
       "description": "Defines the build environment."
     },
+    "include": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "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"
+    },
     "sourceMap": {
       "description": "Output sourcemaps.",
       "default": true,