feat(Jest): support overriding config (#2197)

* Adds support for overriding config in your package.json/jest.config.js and/or react-scripts node_modules.
* Added config setting `jest.configFile` to specify a path to your config file. This file will be loaded using `require`
* The `jest.config` setting now works together with `jest.configFile` to allow you to override the config in your `configFile`

Fixes #2155

.vscode/launch.json

@@ -71,7 +71,10 @@
       "request": "attach",
       "name": "Attach to Port",
       "address": "localhost",
-      "port": 9229
+      "port": 9229,
+      "skipFiles": [
+        "<node_internals>/**"
+      ]
     }
   ]
-}
+}

packages/jest-runner/README.md

@@ -22,25 +22,26 @@ The @stryker-mutator/jest-runner is a plugin for Stryker to enable Jest as a tes
 For the minimum supported versions, see the peerDependencies section in package.json.
 
 ## Configuration
-
-### Configuring Stryker
 Make sure you set the `testRunner` option to "jest" and set `coverageAnalysis` to "off" in your Stryker configuration.
 
 ```javascript
 {
-    testRunner: 'jest'
+    testRunner: 'jest',
     coverageAnalysis: 'off'
 }
 ```
 
-### Configuring Jest
+### Advanced configuration
 The @stryker-mutator/jest-runner also provides a couple of configurable options using the `jest` property in your Stryker config:
 
 ```javascript
 {
     jest: {
         projectType: 'custom',
-        config: require('path/to/your/custom/jestConfig.js'),
+        configFile: 'path/to/your/custom/jestConfig.js',
+        config: {
+            testEnvironment: 'jest-environment-jsdom-sixteen'
+        },
         enableFindRelatedTests: true,
     }
 }
@@ -51,11 +52,12 @@ The @stryker-mutator/jest-runner also provides a couple of configurable options
 | projectType (optional) | The type of project you are working on. | `custom` | `custom` uses the `config` option (see below)|
 | | | | `create-react-app` when you are using [create-react-app](https://github.com/facebook/create-react-app) |
 | | | | `create-react-app-ts` when you are using [create-react-app-typescript](https://github.com/wmonk/create-react-app-typescript) |
-| config (optional) | A custom Jest configuration object. You could also use `require` to load it here. | undefined | |
+| configFile (optional) | The path to your Jest config file. | undefined | |
+| config (optional) | Custom Jest config. This will override file-based config. | undefined | |
 | enableFindRelatedTests (optional) | Whether to run jest with the `--findRelatedTests` flag. When `true`, Jest will only run tests related to the mutated file per test. (See [_--findRelatedTests_](https://jestjs.io/docs/en/cli.html#findrelatedtests-spaceseparatedlistofsourcefiles))  | true | false |
 
-**Note:** When neither of the options are specified it will use the Jest configuration in your "package.json". \
-**Note:** the `projectType` option is ignored when the `config` option is specified.
+**Note:** When the projectType is `custom` and no `configFile` is specified, your `jest.config.js` or `package.json` will be loaded. \
+**Note:** The `configFile` setting is **not** supported for `create-react-app` and `create-react-app-ts`. \
 **Note:** Stryker currently only works for CRA-projects that have not been [_ejected_](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#npm-run-eject).
 
 The following is an example stryker.conf.js file:

packages/jest-runner/schema/jest-runner-options.json

@@ -14,8 +14,12 @@
           "$ref": "#/definitions/jestProjectType",
           "default": "custom"
         },
+        "configFile": {
+          "description": "Path to your Jest config file. Please leave it empty if you want jest configuration to be loaded from package.json or a standard jest configuration file.",
+          "type": "string"
+        },
         "config": {
-          "description": "A custom Jest configuration object. You could also use `require` to load it here. Please leave it empty if you want jest configuration to be loaded from package.json or a standard jest configuration file.",
+          "description": "A custom Jest configuration object. You could also use `require` to load it here.",
           "type": "object"
         },
         "enableFindRelatedTests": {

packages/jest-runner/src/JestTestRunner.ts

@@ -3,37 +3,41 @@ import { Logger } from '@stryker-mutator/api/logging';
 import { commonTokens, Injector, OptionsContext, tokens } from '@stryker-mutator/api/plugin';
 import { RunOptions, RunResult, RunStatus, TestResult, TestRunner, TestStatus } from '@stryker-mutator/api/test_runner';
 
-import { JEST_VERSION_TOKEN, jestTestAdapterFactory } from './jestTestAdapters';
+import { jestTestAdapterFactory } from './jestTestAdapters';
 import JestTestAdapter from './jestTestAdapters/JestTestAdapter';
 import { JestRunnerOptionsWithStrykerOptions } from './JestRunnerOptionsWithStrykerOptions';
+import JestConfigLoader from './configLoaders/JestConfigLoader';
+import { configLoaderToken, processEnvToken, jestTestAdapterToken, jestVersionToken } from './pluginTokens';
+import { configLoaderFactory } from './configLoaders';
+import JEST_OVERRIDE_OPTIONS from './jestOverrideOptions';
 
 export function jestTestRunnerFactory(injector: Injector<OptionsContext>) {
   return injector
-    .provideValue(PROCESS_ENV_TOKEN, process.env)
-    .provideValue(JEST_VERSION_TOKEN, require('jest/package.json').version as string)
-    .provideFactory(JEST_TEST_ADAPTER_TOKEN, jestTestAdapterFactory)
+    .provideValue(processEnvToken, process.env)
+    .provideValue(jestVersionToken, require('jest/package.json').version as string)
+    .provideFactory(jestTestAdapterToken, jestTestAdapterFactory)
+    .provideFactory(configLoaderToken, configLoaderFactory)
     .injectClass(JestTestRunner);
 }
 jestTestRunnerFactory.inject = tokens(commonTokens.injector);
 
-export const PROCESS_ENV_TOKEN = 'PROCESS_ENV_TOKEN';
-export const JEST_TEST_ADAPTER_TOKEN = 'jestTestAdapter';
-
 export default class JestTestRunner implements TestRunner {
   private readonly jestConfig: Jest.Configuration;
 
   private readonly enableFindRelatedTests: boolean;
 
-  public static inject = tokens(commonTokens.logger, commonTokens.options, PROCESS_ENV_TOKEN, JEST_TEST_ADAPTER_TOKEN);
+  public static inject = tokens(commonTokens.logger, commonTokens.options, processEnvToken, jestTestAdapterToken, configLoaderToken);
   constructor(
     private readonly log: Logger,
     options: StrykerOptions,
     private readonly processEnvRef: NodeJS.ProcessEnv,
-    private readonly jestTestAdapter: JestTestAdapter
+    private readonly jestTestAdapter: JestTestAdapter,
+    configLoader: JestConfigLoader
   ) {
     const jestOptions = options as JestRunnerOptionsWithStrykerOptions;
     // Get jest configuration from stryker options and assign it to jestConfig
-    this.jestConfig = (jestOptions.jest.config as unknown) as Jest.Configuration;
+    const configFromFile = configLoader.loadConfig();
+    this.jestConfig = this.mergeConfigSettings(configFromFile, (jestOptions.jest.config as any) || {});
 
     // Get enableFindRelatedTests from stryker jest options or default to true
     this.enableFindRelatedTests = jestOptions.jest.enableFindRelatedTests;
@@ -111,4 +115,14 @@ export default class JestTestRunner implements TestRunner {
         return TestStatus.Skipped;
     }
   }
+
+  private mergeConfigSettings(configFromFile: Jest.Configuration, config: Jest.Configuration) {
+    const stringify = (obj: object) => JSON.stringify(obj, null, 2);
+    this.log.trace(
+      `Merging file-based config ${stringify(configFromFile)} 
+      with custom config ${stringify(config)}
+      and default (internal) stryker config ${JEST_OVERRIDE_OPTIONS}`
+    );
+    return Object.assign(configFromFile, config, JEST_OVERRIDE_OPTIONS);
+  }
 }

packages/jest-runner/src/configLoaders/CustomJestConfigLoader.ts

@@ -1,18 +1,28 @@
 import fs = require('fs');
 import path from 'path';
 
+import { Logger } from '@stryker-mutator/api/logging';
+import { tokens, commonTokens } from '@stryker-mutator/api/plugin';
+import { StrykerOptions } from '@stryker-mutator/api/core';
+
+import { loaderToken, projectRootToken } from '../pluginTokens';
+import { JestRunnerOptionsWithStrykerOptions } from '../JestRunnerOptionsWithStrykerOptions';
+
 import JestConfigLoader from './JestConfigLoader';
 import { NodeRequireFunction } from './NodeRequireFunction';
 
 /**
  * The Default config loader will load the Jest configuration using the package.json in the package root
  */
 export default class CustomJestConfigLoader implements JestConfigLoader {
-  private readonly _projectRoot: string;
+  public static inject = tokens(commonTokens.logger, commonTokens.options, loaderToken, projectRootToken);
 
-  constructor(projectRoot: string, private readonly _loader: NodeRequireFunction = require) {
-    this._projectRoot = projectRoot;
-  }
+  constructor(
+    private readonly log: Logger,
+    private readonly options: StrykerOptions,
+    private readonly require: NodeRequireFunction,
+    private readonly projectRoot: string
+  ) {}
 
   public loadConfig(): Jest.Configuration {
     const jestConfig = this.readConfigFromJestConfigFile() || this.readConfigFromPackageJson() || {};
@@ -21,15 +31,22 @@ export default class CustomJestConfigLoader implements JestConfigLoader {
 
   private readConfigFromJestConfigFile() {
     try {
-      return this._loader(path.join(this._projectRoot, 'jest.config.js'));
+      const jestOptions = this.options as JestRunnerOptionsWithStrykerOptions;
+      const configFilePath = path.join(this.projectRoot, jestOptions.jest?.configFile || 'jest.config.js');
+      const config = this.require(configFilePath);
+      this.log.debug(`Read Jest config from ${configFilePath}`);
+      return config;
     } catch {
       /* Don't return anything (implicitly return undefined) */
     }
   }
 
   private readConfigFromPackageJson() {
     try {
-      return JSON.parse(fs.readFileSync(path.join(this._projectRoot, 'package.json'), 'utf8')).jest;
+      const configFilePath = path.join(this.projectRoot, 'package.json');
+      const config = JSON.parse(fs.readFileSync(configFilePath, 'utf8')).jest;
+      this.log.debug(`Read Jest config from ${configFilePath}`);
+      return config;
     } catch {
       /* Don't return anything (implicitly return undefined) */
     }

packages/jest-runner/src/configLoaders/ReactScriptsJestConfigLoader.ts

@@ -1,15 +1,16 @@
 import path from 'path';
 
+import { tokens } from '@stryker-mutator/api/plugin';
+
 import { createReactJestConfig } from '../utils/createReactJestConfig';
+import { projectRootToken, resolveToken } from '../pluginTokens';
 
 import JestConfigLoader from './JestConfigLoader';
 
 export default class ReactScriptsJestConfigLoader implements JestConfigLoader {
-  private readonly projectRoot: string;
+  public static inject = tokens(resolveToken, projectRootToken);
 
-  constructor(projectRoot: string, private readonly resolve: RequireResolve = require.resolve) {
-    this.projectRoot = projectRoot;
-  }
+  constructor(private readonly resolve: RequireResolve, private readonly projectRoot: string) {}
 
   public loadConfig(): Jest.Configuration {
     try {
@@ -19,9 +20,6 @@ export default class ReactScriptsJestConfigLoader implements JestConfigLoader {
       // Create the React configuration for Jest
       const jestConfiguration = this.createJestConfig(reactScriptsLocation);
 
-      // Set test environment to jsdom (otherwise Jest won't run)
-      jestConfiguration.testEnvironment = 'jsdom';
-
       return jestConfiguration;
     } catch (e) {
       if (this.isNodeErrnoException(e) && e.code === 'MODULE_NOT_FOUND') {

packages/jest-runner/src/configLoaders/ReactScriptsTSJestConfigLoader.ts

@@ -1,15 +1,16 @@
 import * as path from 'path';
 
+import { tokens } from '@stryker-mutator/api/plugin';
+
 import { createReactTsJestConfig } from '../utils/createReactJestConfig';
+import { projectRootToken, resolveToken } from '../pluginTokens';
 
 import JestConfigLoader from './JestConfigLoader';
 
 export default class ReactScriptsTSJestConfigLoader implements JestConfigLoader {
-  private readonly projectRoot: string;
+  public static inject = tokens(resolveToken, projectRootToken);
 
-  constructor(projectRoot: string, private readonly resolve = require.resolve) {
-    this.projectRoot = projectRoot;
-  }
+  constructor(private readonly resolve: RequireResolve, private readonly projectRoot: string) {}
 
   public loadConfig(): Jest.Configuration {
     try {
@@ -18,10 +19,7 @@ export default class ReactScriptsTSJestConfigLoader implements JestConfigLoader
 
       // Create the React configuration for Jest
       const jestConfiguration = this.createJestConfig(reactScriptsTsLocation);
-
-      // Set test environment to jsdom (otherwise Jest won't run)
       jestConfiguration.testEnvironment = 'jsdom';
-
       return jestConfiguration;
     } catch (e) {
       if (this.isNodeErrnoException(e) && e.code === 'MODULE_NOT_FOUND') {

packages/jest-runner/src/configLoaders/index.ts

@@ -0,0 +1,50 @@
+import { tokens, commonTokens, Injector, OptionsContext } from '@stryker-mutator/api/plugin';
+import { StrykerOptions } from '@stryker-mutator/api/core';
+import { Logger } from '@stryker-mutator/api/logging';
+
+import { JestRunnerOptionsWithStrykerOptions } from '../JestRunnerOptionsWithStrykerOptions';
+import { loaderToken, resolveToken, projectRootToken } from '../pluginTokens';
+
+import CustomJestConfigLoader from './CustomJestConfigLoader';
+import ReactScriptsJestConfigLoader from './ReactScriptsJestConfigLoader';
+import ReactScriptsTSJestConfigLoader from './ReactScriptsTSJestConfigLoader';
+
+configLoaderFactory.inject = tokens(commonTokens.options, commonTokens.injector, commonTokens.logger);
+export function configLoaderFactory(options: StrykerOptions, injector: Injector<OptionsContext>, log: Logger) {
+  const warnAboutConfigFile = (projectType: string, configFile: string | undefined) => {
+    if (configFile) {
+      log.warn(`Config setting "configFile" is not supported for projectType "${projectType}"`);
+    }
+  };
+  const optionsWithJest: JestRunnerOptionsWithStrykerOptions = options as JestRunnerOptionsWithStrykerOptions;
+
+  const configLoaderInjector = injector
+    .provideValue(loaderToken, require)
+    .provideValue(resolveToken, require.resolve)
+    .provideValue(projectRootToken, process.cwd());
+
+  switch (optionsWithJest.jest.projectType) {
+    case 'custom':
+      return configLoaderInjector.injectClass(CustomJestConfigLoader);
+    case 'create-react-app':
+      warnAboutConfigFile(optionsWithJest.jest.projectType, optionsWithJest.jest.configFile);
+      return configLoaderInjector.injectClass(ReactScriptsJestConfigLoader);
+    case 'create-react-app-ts':
+      warnAboutConfigFile(optionsWithJest.jest.projectType, optionsWithJest.jest.configFile);
+      return configLoaderInjector.injectClass(ReactScriptsTSJestConfigLoader);
+    case 'react':
+      log.warn(
+        'DEPRECATED: The projectType "react" is deprecated. Use projectType "create-react-app" for react projects created by "create-react-app" or use "custom" for other react projects.'
+      );
+      warnAboutConfigFile(optionsWithJest.jest.projectType, optionsWithJest.jest.configFile);
+      return configLoaderInjector.injectClass(ReactScriptsJestConfigLoader);
+    case 'react-ts':
+      log.warn(
+        'DEPRECATED: The projectType "react-ts" is deprecated. Use projectType "create-react-app-ts" for react projects created by "create-react-app" or use "custom" for other react projects.'
+      );
+      warnAboutConfigFile(optionsWithJest.jest.projectType, optionsWithJest.jest.configFile);
+      return configLoaderInjector.injectClass(ReactScriptsTSJestConfigLoader);
+    default:
+      throw new Error(`No configLoader available for ${optionsWithJest.jest.projectType}`);
+  }
+}

packages/jest-runner/src/index.ts

@@ -1,12 +1,11 @@
-import { declareClassPlugin, declareFactoryPlugin, PluginKind } from '@stryker-mutator/api/plugin';
+import { declareFactoryPlugin, PluginKind } from '@stryker-mutator/api/plugin';
+
+import strykerValidationSchema from '../schema/jest-runner-options.json';
 
-import JestOptionsEditor from './JestOptionsEditor';
 import { jestTestRunnerFactory } from './JestTestRunner';
 
 process.env.BABEL_ENV = 'test';
 
-export const strykerPlugins = [
-  declareClassPlugin(PluginKind.OptionsEditor, 'jest', JestOptionsEditor),
-  declareFactoryPlugin(PluginKind.TestRunner, 'jest', jestTestRunnerFactory),
-];
-export * as strykerValidationSchema from '../schema/jest-runner-options.json';
+export const strykerPlugins = [declareFactoryPlugin(PluginKind.TestRunner, 'jest', jestTestRunnerFactory)];
+
+export { strykerValidationSchema };