[WIP] Migrate jest-repl to typescript (#8000)

CHANGELOG.md

@@ -62,6 +62,7 @@
 - `[jest-runner]`: Migrate to TypeScript ([#7968](https://github.com/facebook/jest/pull/7968))
 - `[jest-runtime]`: Migrate to TypeScript ([#7964](https://github.com/facebook/jest/pull/7964), [#7988](https://github.com/facebook/jest/pull/7988))
 - `[@jest/fake-timers]`: Extract FakeTimers class from `jest-util` into a new separate package ([#7987](https://github.com/facebook/jest/pull/7987))
+- `[jest-repl]`: Migrate to TypeScript ([#8000](https://github.com/facebook/jest/pull/8000))
 
 ### Performance
 

packages/jest-repl/package.json

@@ -8,7 +8,10 @@
   },
   "license": "MIT",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
   "dependencies": {
+    "@jest/transform": "^24.1.0",
+    "@jest/types": "^24.1.0",
     "jest-config": "^24.1.0",
     "jest-runtime": "^24.1.0",
     "jest-validate": "^24.0.0",

packages/jest-repl/src/cli/args.js → packages/jest-repl/src/cli/args.ts

@@ -4,20 +4,18 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
  */
 
 import Runtime from 'jest-runtime';
 
 export const usage = 'Usage: $0 [--config=<pathToConfigFile>]';
 
-export const options = {
-  ...Runtime.getCLIOptions(),
+export const options = Object.assign({}, Runtime.getCLIOptions(), {
   replname: {
     alias: 'r',
     description:
       'The "name" of the file given to transformers to be ' +
       'transformed. For example, "repl.ts" if using a TypeScript transformer.',
     type: 'string',
   },
-};
+});

packages/jest-repl/src/cli/index.js → packages/jest-repl/src/cli/index.ts

@@ -5,26 +5,26 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
  */
 
-import path from 'path';
-
 import Runtime from 'jest-runtime';
 import yargs from 'yargs';
+// @ts-ignore: Wait for jest-validate to get migrated
 import {validateCLIOptions} from 'jest-validate';
 import {deprecationEntries} from 'jest-config';
-import {version as VERSION} from '../../package.json';
 import * as args from './args';
 
-const REPL_SCRIPT = path.resolve(__dirname, './repl.js');
+const {version: VERSION} = require('../../package.json');
+
+const REPL_SCRIPT = require.resolve('./repl.js');
 
-module.exports = function() {
+export = function() {
   const argv = yargs.usage(args.usage).options(args.options).argv;
 
   validateCLIOptions(argv, {...args.options, deprecationEntries});
 
   argv._ = [REPL_SCRIPT];
 
+  // @ts-ignore: not the same arguments
   Runtime.runCLI(argv, [`Jest REPL v${VERSION}`]);
 };

packages/jest-repl/src/cli/repl.js → packages/jest-repl/src/cli/repl.ts

@@ -5,30 +5,37 @@
  * 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, ProjectConfig} from 'types/Config';
-
-declare var jestGlobalConfig: GlobalConfig;
-declare var jestProjectConfig: ProjectConfig;
-declare var jest: Object;
+declare const jestGlobalConfig: Config.GlobalConfig;
+declare const jestProjectConfig: Config.ProjectConfig;
 
 import path from 'path';
 import repl from 'repl';
 import vm from 'vm';
+import {Transformer} from '@jest/transform';
+import {Config} from '@jest/types';
 
-let transformer;
+let transformer: Transformer;
 
-const evalCommand = (cmd, context, filename, callback, config) => {
+const evalCommand: repl.REPLEval = (
+  cmd: string,
+  _context: any,
+  _filename: string,
+  callback: (e: Error | null, result?: any) => void,
+) => {
   let result;
   try {
     if (transformer) {
-      cmd = transformer.process(
+      const transformResult = transformer.process(
         cmd,
         jestGlobalConfig.replname || 'jest.js',
         jestProjectConfig,
       );
+      cmd =
+        typeof transformResult === 'string'
+          ? transformResult
+          : transformResult.code;
     }
     result = vm.runInThisContext(cmd);
   } catch (e) {
@@ -37,7 +44,7 @@ const evalCommand = (cmd, context, filename, callback, config) => {
   return callback(null, result);
 };
 
-const isRecoverableError = error => {
+const isRecoverableError = (error: Error) => {
   if (error && error.name === 'SyntaxError') {
     return [
       'Unterminated template',
@@ -59,7 +66,6 @@ if (jestProjectConfig.transform) {
     }
   }
   if (transformerPath) {
-    /* $FlowFixMe */
     transformer = require(transformerPath);
     if (typeof transformer.process !== 'function') {
       throw new TypeError(
@@ -69,17 +75,15 @@ if (jestProjectConfig.transform) {
   }
 }
 
-const replInstance = repl.start({
+const replInstance: repl.REPLServer = repl.start({
   eval: evalCommand,
   prompt: '\u203A ',
   useGlobal: true,
 });
 
-// $FlowFixMe: https://github.com/facebook/flow/pull/4713
-replInstance.context.require = moduleName => {
+replInstance.context.require = (moduleName: string) => {
   if (/(\/|\\|\.)/.test(moduleName)) {
     moduleName = path.resolve(process.cwd(), moduleName);
   }
-  /* $FlowFixMe */
   return require(moduleName);
 };

packages/jest-repl/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "build"
+  },
+  "references": [
+    {"path": "../jest-config"},
+    {"path": "../jest-runtime"},
+    {"path": "../jest-transform"},
+    {"path": "../jest-types"}
+    // TODO: Wait for this to get migrated
+    // {"path": "../jest-validate"}
+  ]
+}