Migrate jest-runner to typescript (#7968)

Author: Alcedo Nathaniel De Guzman Jr

CHANGELOG.md

@@ -56,6 +56,7 @@
 - `[expect]`: Migrate to TypeScript ([#7919](https://github.com/facebook/jest/pull/7919))
 - `[jest-circus]`: Migrate to TypeScript ([#7916](https://github.com/facebook/jest/pull/7916))
 - `[jest-phabricator]`: Migrate to TypeScript ([#7965](https://github.com/facebook/jest/pull/7965))
+- `[jest-runner]`: Migrate to TypeScript ([#7968](https://github.com/facebook/jest/pull/7968))
 
 ### Performance
 

packages/jest-runner/package.json

@@ -8,7 +8,9 @@
   },
   "license": "MIT",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
   "dependencies": {
+    "@jest/types": "^24.1.0",
     "chalk": "^2.4.2",
     "exit": "^0.1.2",
     "graceful-fs": "^4.1.15",
@@ -18,6 +20,7 @@
     "jest-jasmine2": "^24.1.0",
     "jest-leak-detector": "^24.0.0",
     "jest-message-util": "^24.0.0",
+    "jest-resolve": "^24.1.0",
     "jest-runtime": "^24.1.0",
     "jest-util": "^24.0.0",
     "jest-worker": "^24.0.0",

packages/jest-runner/src/__tests__/testRunner.test.js

@@ -7,7 +7,6 @@
  */
 
 import {TestWatcher} from '@jest/core';
-// eslint-disable-next-line import/default
 import TestRunner from '../index';
 
 let mockWorkerFarm;

packages/jest-runner/src/index.js renamed to packages/jest-runner/src/index.ts

@@ -3,37 +3,36 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {GlobalConfig} from 'types/Config';
-import type {
+import {Config, TestResult} from '@jest/types';
+import exit from 'exit';
+import throat from 'throat';
+import Worker from 'jest-worker';
+import runTest from './runTest';
+import {worker} from './testWorker';
+import {
   OnTestFailure,
   OnTestStart,
   OnTestSuccess,
   Test,
   TestRunnerContext,
   TestRunnerOptions,
   TestWatcher,
-} from 'types/TestRunner';
-
-import typeof {worker} from './testWorker';
-
-import exit from 'exit';
-import runTest from './runTest';
-import throat from 'throat';
-import Worker from 'jest-worker';
+  WatcherState,
+} from './types';
 
 const TEST_WORKER_PATH = require.resolve('./testWorker');
 
-type WorkerInterface = Worker & {worker: worker};
+interface WorkerInterface extends Worker {
+  worker: typeof worker;
+}
 
 class TestRunner {
-  _globalConfig: GlobalConfig;
-  _context: TestRunnerContext;
+  private _globalConfig: Config.GlobalConfig;
+  private _context: TestRunnerContext;
 
-  constructor(globalConfig: GlobalConfig, context?: TestRunnerContext) {
+  constructor(globalConfig: Config.GlobalConfig, context?: TestRunnerContext) {
     this._globalConfig = globalConfig;
     this._context = context || {};
   }
@@ -57,7 +56,7 @@ class TestRunner {
         ));
   }
 
-  async _createInBandTestRun(
+  private async _createInBandTestRun(
     tests: Array<Test>,
     watcher: TestWatcher,
     onStart: OnTestStart,
@@ -91,19 +90,19 @@ class TestRunner {
     );
   }
 
-  async _createParallelTestRun(
+  private async _createParallelTestRun(
     tests: Array<Test>,
     watcher: TestWatcher,
     onStart: OnTestStart,
     onResult: OnTestSuccess,
     onFailure: OnTestFailure,
   ) {
-    const worker: WorkerInterface = new Worker(TEST_WORKER_PATH, {
+    const worker = new Worker(TEST_WORKER_PATH, {
       exposedMethods: ['worker'],
       forkOptions: {stdio: 'pipe'},
       maxRetries: 3,
       numWorkers: this._globalConfig.maxWorkers,
-    });
+    }) as WorkerInterface;
 
     if (worker.getStdout()) worker.getStdout().pipe(process.stdout);
     if (worker.getStderr()) worker.getStderr().pipe(process.stderr);
@@ -112,7 +111,7 @@ class TestRunner {
 
     // Send test suites to workers continuously instead of all at once to track
     // the start time of individual tests.
-    const runTestInWorker = test =>
+    const runTestInWorker = (test: Test) =>
       mutex(async () => {
         if (watcher.isInterrupted()) {
           return Promise.reject();
@@ -131,7 +130,7 @@ class TestRunner {
         });
       });
 
-    const onError = async (err, test) => {
+    const onError = async (err: TestResult.SerializableError, test: Test) => {
       await onFailure(test, err);
       if (err.type === 'ProcessTerminatedError') {
         console.error(
@@ -143,7 +142,7 @@ class TestRunner {
     };
 
     const onInterrupt = new Promise((_, reject) => {
-      watcher.on('change', state => {
+      watcher.on('change', (state: WatcherState) => {
         if (state.interrupted) {
           reject(new CancelRun());
         }
@@ -164,10 +163,10 @@ class TestRunner {
 }
 
 class CancelRun extends Error {
-  constructor(message: ?string) {
+  constructor(message?: string) {
     super(message);
     this.name = 'CancelRun';
   }
 }
 
-module.exports = TestRunner;
+export = TestRunner;

packages/jest-runner/src/runTest.js renamed to packages/jest-runner/src/runTest.ts

@@ -4,16 +4,16 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
  */
 
-import type {EnvironmentClass} from 'types/Environment';
-import type {GlobalConfig, Path, ProjectConfig} from 'types/Config';
-import type {Resolver} from 'types/Resolve';
-import type {TestFramework, TestRunnerContext} from 'types/TestRunner';
-import type {TestResult} from 'types/TestResult';
-import type RuntimeClass from 'jest-runtime';
-
+import {
+  Environment,
+  Config,
+  TestResult,
+  Console as ConsoleType,
+} from '@jest/types';
+// @ts-ignore: not migrated to TS
+import RuntimeClass from 'jest-runtime';
 import fs from 'graceful-fs';
 import {
   BufferedConsole,
@@ -24,22 +24,31 @@ import {
   setGlobal,
 } from 'jest-util';
 import LeakDetector from 'jest-leak-detector';
+import Resolver from 'jest-resolve';
+// @ts-ignore: not migrated to TS
 import {getTestEnvironment} from 'jest-config';
 import * as docblock from 'jest-docblock';
 import {formatExecError} from 'jest-message-util';
-import sourcemapSupport from 'source-map-support';
+import sourcemapSupport, {
+  Options as SourceMapOptions,
+} from 'source-map-support';
 import chalk from 'chalk';
+import {TestFramework, TestRunnerContext} from './types';
 
 type RunTestInternalResult = {
-  leakDetector: ?LeakDetector,
-  result: TestResult,
+  leakDetector: LeakDetector | null;
+  result: TestResult.TestResult;
 };
 
 function freezeConsole(
+  // @ts-ignore: Correct types when `jest-util` is ESM
   testConsole: BufferedConsole | Console | NullConsole,
-  config: ProjectConfig,
+  config: Config.ProjectConfig,
 ) {
-  testConsole._log = function fakeConsolePush(_type, message) {
+  testConsole._log = function fakeConsolePush(
+    _type: ConsoleType.LogType,
+    message: ConsoleType.LogMessage,
+  ) {
     const error = new ErrorWithStack(
       `${chalk.red(
         `${chalk.bold(
@@ -73,11 +82,11 @@ function freezeConsole(
 // references to verify if there is a leak, which is not maintainable and error
 // prone. That's why "runTestInternal" CANNOT be inlined inside "runTest".
 async function runTestInternal(
-  path: Path,
-  globalConfig: GlobalConfig,
-  config: ProjectConfig,
+  path: Config.Path,
+  globalConfig: Config.GlobalConfig,
+  config: Config.ProjectConfig,
   resolver: Resolver,
-  context: ?TestRunnerContext,
+  context?: TestRunnerContext,
 ): Promise<RunTestInternalResult> {
   const testSource = fs.readFileSync(path, 'utf8');
   const parsedDocblock = docblock.parse(docblock.extract(testSource));
@@ -92,21 +101,22 @@ async function runTestInternal(
     });
   }
 
-  /* $FlowFixMe */
-  const TestEnvironment = (require(testEnvironment): EnvironmentClass);
-  const testFramework = ((process.env.JEST_CIRCUS === '1'
-    ? require('jest-circus/runner') // eslint-disable-line import/no-extraneous-dependencies
-    : /* $FlowFixMe */
-      require(config.testRunner)): TestFramework);
-  const Runtime = ((config.moduleLoader
-    ? /* $FlowFixMe */
-      require(config.moduleLoader)
-    : require('jest-runtime')): Class<RuntimeClass>);
+  const TestEnvironment: Environment.EnvironmentClass = require(testEnvironment);
+  const testFramework: TestFramework =
+    process.env.JEST_CIRCUS === '1'
+      ? require('jest-circus/runner') // eslint-disable-line import/no-extraneous-dependencies
+      : require(config.testRunner);
+  const Runtime: RuntimeClass = config.moduleLoader
+    ? require(config.moduleLoader)
+    : require('jest-runtime');
 
-  let runtime = undefined;
+  let runtime: RuntimeClass = undefined;
 
   const consoleOut = globalConfig.useStderr ? process.stderr : process.stdout;
-  const consoleFormatter = (type, message) =>
+  const consoleFormatter = (
+    type: ConsoleType.LogType,
+    message: ConsoleType.LogMessage,
+  ) =>
     getConsoleOutput(
       config.cwd,
       !!globalConfig.verbose,
@@ -150,7 +160,7 @@ async function runTestInternal(
 
   const start = Date.now();
 
-  const sourcemapOptions = {
+  const sourcemapOptions: SourceMapOptions = {
     environment: 'node',
     handleUncaughtExceptions: false,
     retrieveSourceMap: source => {
@@ -160,7 +170,7 @@ async function runTestInternal(
       if (sourceMapSource) {
         try {
           return {
-            map: JSON.parse(fs.readFileSync(sourceMapSource)),
+            map: JSON.parse(fs.readFileSync(sourceMapSource, 'utf8')),
             url: source,
           };
         } catch (e) {}
@@ -187,7 +197,7 @@ async function runTestInternal(
   ) {
     const realExit = environment.global.process.exit;
 
-    environment.global.process.exit = function exit(...args) {
+    environment.global.process.exit = function exit(...args: Array<any>) {
       const error = new ErrorWithStack(
         `process.exit called with "${args.join(', ')}"`,
         exit,
@@ -210,7 +220,7 @@ async function runTestInternal(
   try {
     await environment.setup();
 
-    let result: TestResult;
+    let result: TestResult.TestResult;
 
     try {
       result = await testFramework(
@@ -259,17 +269,18 @@ async function runTestInternal(
   } finally {
     await environment.teardown();
 
+    // @ts-ignore: https://github.com/DefinitelyTyped/DefinitelyTyped/pull/33351
     sourcemapSupport.resetRetrieveHandlers();
   }
 }
 
 export default async function runTest(
-  path: Path,
-  globalConfig: GlobalConfig,
-  config: ProjectConfig,
+  path: Config.Path,
+  globalConfig: Config.GlobalConfig,
+  config: Config.ProjectConfig,
   resolver: Resolver,
-  context: ?TestRunnerContext,
-): Promise<TestResult> {
+  context?: TestRunnerContext,
+): Promise<TestResult.TestResult> {
   const {leakDetector, result} = await runTestInternal(
     path,
     globalConfig,