feat(create-jest): Add npm init / yarn create initialiser (#14453)

Co-authored-by: Tom Mrazauskas <tom@mrazauskas.de>

.eslintrc.cjs

@@ -357,7 +357,7 @@ module.exports = {
       files: [
         'scripts/*',
         'packages/*/__benchmarks__/test.js',
-        'packages/jest-cli/src/init/index.ts',
+        'packages/create-jest/src/runCreate.ts',
         'packages/jest-repl/src/cli/runtime-cli.ts',
       ],
       rules: {

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ### Features
 
+- `[create-jest]` Add `npm init` / `yarn create` initialiser for Jest projects ([#14465](https://github.com/jestjs/jest/pull/14453))
+
 ### Fixes
 
 - `[jest-snapshot]` Allow for strings as well as template literals in inline snapshots ([#14465](https://github.com/jestjs/jest/pull/14465))
@@ -13,6 +15,8 @@
 
 ### Chore & Maintenance
 
+- `[jest-cli]` Move internal config initialisation logic to the `create-jest` package ([#14465](https://github.com/jestjs/jest/pull/14453))
+
 ## 29.6.4
 
 ### Fixes

README.md

@@ -131,7 +131,7 @@ If you'd like to learn more about running `jest` through the command line, take
 Based on your project, Jest will ask you a few questions and will create a basic configuration file with a short description for each option:
 
 ```bash
-jest --init
+yarn create jest
 ```
 
 ### Using Babel

docs/GettingStarted.md

@@ -67,8 +67,8 @@ If you'd like to learn more about running `jest` through the command line, take
 
 Based on your project, Jest will ask you a few questions and will create a basic configuration file with a short description for each option:
 
-```bash
-jest --init
+```bash npm2yarn
+npm init jest@latest
 ```
 
 ### Using Babel

package.json

@@ -111,7 +111,7 @@
     "test": "yarn lint && yarn jest",
     "typecheck": "yarn typecheck:examples && yarn typecheck:tests",
     "typecheck:examples": "tsc -p examples/angular --noEmit && tsc -p examples/expect-extend --noEmit && tsc -p examples/typescript --noEmit",
-    "typecheck:tests": "tsc -b packages/{babel-jest,babel-plugin-jest-hoist,diff-sequences,expect,expect-utils,jest-circus,jest-cli,jest-config,jest-console,jest-snapshot,jest-util,jest-validate,jest-watcher,jest-worker,pretty-format}/**/__tests__",
+    "typecheck:tests": "tsc -b packages/{babel-jest,babel-plugin-jest-hoist,create-jest,diff-sequences,expect,expect-utils,jest-circus,jest-cli,jest-config,jest-console,jest-snapshot,jest-util,jest-validate,jest-watcher,jest-worker,pretty-format}/**/__tests__",
     "verify-old-ts": "node ./scripts/verifyOldTs.mjs",
     "verify-pnp": "node ./scripts/verifyPnP.mjs",
     "watch": "yarn build:js && node ./scripts/watch.mjs",

packages/create-jest/.npmignore

@@ -0,0 +1,8 @@
+**/__mocks__/**
+**/__tests__/**
+__typetests__
+src
+tsconfig.json
+tsconfig.tsbuildinfo
+api-extractor.json
+.eslintcache

packages/create-jest/README.md

@@ -0,0 +1,11 @@
+# create-jest
+
+> Getting started with Jest with a single command
+
+```bash
+npm init jest@latest
+# Or for Yarn
+yarn create jest
+# Or for pnpm
+pnpm create jest
+```

packages/create-jest/bin/create-jest.js

@@ -0,0 +1,8 @@
+#!/usr/bin/env node
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+require('..').runCLI();

packages/create-jest/package.json

@@ -0,0 +1,42 @@
+{
+  "name": "create-jest",
+  "description": "Create a new Jest project",
+  "version": "29.6.4",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/jestjs/jest.git",
+    "directory": "packages/create-jest"
+  },
+  "license": "MIT",
+  "bin": "./bin/create-jest.js",
+  "main": "./build/index.js",
+  "types": "./build/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./build/index.d.ts",
+      "default": "./build/index.js"
+    },
+    "./package.json": "./package.json",
+    "./bin/create-jest": "./bin/create-jest.js"
+  },
+  "dependencies": {
+    "@jest/types": "workspace:^",
+    "chalk": "^4.0.0",
+    "exit": "^0.1.2",
+    "graceful-fs": "^4.2.9",
+    "jest-config": "workspace:^",
+    "jest-util": "workspace:^",
+    "prompts": "^2.0.1"
+  },
+  "engines": {
+    "node": "^14.15.0 || ^16.10.0 || >=18.0.0"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "devDependencies": {
+    "@types/exit": "^0.1.30",
+    "@types/graceful-fs": "^4.1.3",
+    "@types/prompts": "^2.0.1"
+  }
+}

packages/jest-cli/src/init/__tests__/init.test.ts → packages/create-jest/src/__tests__/init.test.ts

@@ -10,7 +10,7 @@ import * as path from 'path';
 import {writeFileSync} from 'graceful-fs';
 import * as prompts from 'prompts';
 import {constants} from 'jest-config';
-import init from '../';
+import {runCreate} from '../runCreate';
 
 const {JEST_CONFIG_EXT_ORDER} = constants;
 
@@ -44,7 +44,7 @@ describe('init', () => {
       it('should return the default configuration (an empty config)', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenJestConfigFilename =
           jest.mocked(writeFileSync).mock.calls[0][0];
@@ -71,7 +71,7 @@ describe('init', () => {
       it('should generate empty config with mjs extension', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({});
 
-        await init(resolveFromFixture('type-module'));
+        await runCreate(resolveFromFixture('type-module'));
 
         const writtenJestConfigFilename =
           jest.mocked(writeFileSync).mock.calls[0][0];
@@ -93,7 +93,7 @@ describe('init', () => {
       it('should create configuration for {clearMocks: true}', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({clearMocks: true});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenJestConfig = jest.mocked(writeFileSync).mock.calls[0][1];
         const evaluatedConfig = eval(writtenJestConfig as string) as Record<
@@ -107,7 +107,7 @@ describe('init', () => {
       it('should create configuration for {coverage: true}', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({coverage: true});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenJestConfig = jest.mocked(writeFileSync).mock.calls[0][1];
         const evaluatedConfig = eval(writtenJestConfig as string) as Record<
@@ -124,7 +124,7 @@ describe('init', () => {
       it('should create configuration for {coverageProvider: "babel"}', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({coverageProvider: 'babel'});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenJestConfig = jest.mocked(writeFileSync).mock.calls[0][1];
         const evaluatedConfig = eval(writtenJestConfig as string) as Record<
@@ -138,7 +138,7 @@ describe('init', () => {
       it('should create configuration for {coverageProvider: "v8"}', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({coverageProvider: 'v8'});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenJestConfig = jest.mocked(writeFileSync).mock.calls[0][1];
         const evaluatedConfig = eval(writtenJestConfig as string) as Record<
@@ -152,7 +152,7 @@ describe('init', () => {
       it('should create configuration for {environment: "jsdom"}', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({environment: 'jsdom'});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenJestConfig = jest.mocked(writeFileSync).mock.calls[0][1];
         const evaluatedConfig = eval(writtenJestConfig as string) as Record<
@@ -165,7 +165,7 @@ describe('init', () => {
       it('should create configuration for {environment: "node"}', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({environment: 'node'});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenJestConfig = jest.mocked(writeFileSync).mock.calls[0][1];
         const evaluatedConfig = eval(writtenJestConfig as string) as Record<
@@ -178,7 +178,7 @@ describe('init', () => {
       it('should create package.json with configured test command when {scripts: true}', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({scripts: true});
 
-        await init(resolveFromFixture('only-package-json'));
+        await runCreate(resolveFromFixture('only-package-json'));
 
         const writtenPackageJson = jest.mocked(writeFileSync).mock.calls[0][1];
         const parsedPackageJson = JSON.parse(writtenPackageJson as string) as {
@@ -196,7 +196,7 @@ describe('init', () => {
       expect.assertions(1);
 
       try {
-        await init(resolveFromFixture('no-package-json'));
+        await runCreate(resolveFromFixture('no-package-json'));
       } catch (error) {
         expect((error as Error).message).toMatch(
           'Could not find a "package.json" file in',
@@ -215,7 +215,9 @@ describe('init', () => {
             .mockResolvedValueOnce({continue: true})
             .mockResolvedValueOnce({});
 
-          await init(resolveFromFixture(`has-jest-config-file-${extension}`));
+          await runCreate(
+            resolveFromFixture(`has-jest-config-file-${extension}`),
+          );
 
           expect(jest.mocked(prompts).mock.calls[0][0]).toMatchSnapshot();
 
@@ -230,7 +232,9 @@ describe('init', () => {
         it('user answered with "No"', async () => {
           jest.mocked(prompts).mockResolvedValueOnce({continue: false});
 
-          await init(resolveFromFixture(`has-jest-config-file-${extension}`));
+          await runCreate(
+            resolveFromFixture(`has-jest-config-file-${extension}`),
+          );
           // return after first prompt
           expect(prompts).toHaveBeenCalledTimes(1);
         });
@@ -243,7 +247,7 @@ describe('init', () => {
       it('user answered with "Yes"', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({useTypescript: true});
 
-        await init(resolveFromFixture('test-generated-jest-config-ts'));
+        await runCreate(resolveFromFixture('test-generated-jest-config-ts'));
 
         expect(jest.mocked(prompts).mock.calls[0][0]).toMatchSnapshot();
 
@@ -264,7 +268,7 @@ describe('init', () => {
       it('user answered with "No"', async () => {
         jest.mocked(prompts).mockResolvedValueOnce({useTypescript: false});
 
-        await init(resolveFromFixture('test-generated-jest-config-ts'));
+        await runCreate(resolveFromFixture('test-generated-jest-config-ts'));
 
         const jestConfigFileName = jest.mocked(writeFileSync).mock.calls[0][0];
 
@@ -282,7 +286,7 @@ describe('init', () => {
         .mockResolvedValueOnce({continue: true})
         .mockResolvedValueOnce({});
 
-      await init(resolveFromFixture('has-jest-config-in-package-json'));
+      await runCreate(resolveFromFixture('has-jest-config-in-package-json'));
 
       expect(jest.mocked(prompts).mock.calls[0][0]).toMatchSnapshot();
 
@@ -296,7 +300,7 @@ describe('init', () => {
     it('should not ask "test script question"', async () => {
       jest.mocked(prompts).mockResolvedValueOnce({});
 
-      await init(resolveFromFixture('test-script-configured'));
+      await runCreate(resolveFromFixture('test-script-configured'));
 
       const questions = jest.mocked(prompts).mock.calls[0][0] as Array<
         prompts.PromptObject<string>

packages/create-jest/src/__tests__/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "extends": "../../../../tsconfig.test.json",
+  "include": ["./**/*"],
+  "references": [{"path": "../../"}]
+}

packages/jest-cli/src/init/errors.ts → packages/create-jest/src/errors.ts

@@ -16,10 +16,7 @@ export class NotFoundPackageJsonError extends Error {
 
 export class MalformedPackageJsonError extends Error {
   constructor(packageJsonPath: string) {
-    super(
-      `There is malformed json in ${packageJsonPath}\n` +
-        'Fix it, and then run "jest --init"',
-    );
+    super(`There is malformed json in ${packageJsonPath}`);
     this.name = '';
     // eslint-disable-next-line @typescript-eslint/no-empty-function
     Error.captureStackTrace(this, () => {});

packages/jest-cli/src/init/generateConfigFile.ts → packages/create-jest/src/generateConfigFile.ts

@@ -7,13 +7,16 @@
 
 import type {Config} from '@jest/types';
 import {defaults, descriptions} from 'jest-config';
+import type {PromptsResults} from './types';
 
 const stringifyOption = (
   option: keyof Config.InitialOptions,
   map: Partial<Config.InitialOptions>,
   linePrefix = '',
 ): string => {
-  const optionDescription = `  // ${descriptions[option]}`;
+  const description = descriptions[option];
+  const optionDescription =
+    description != null && description.length > 0 ? `  // ${description}` : '';
   const stringifiedObject = `${option}: ${JSON.stringify(
     map[option],
     null,
@@ -27,7 +30,7 @@ const stringifyOption = (
 };
 
 const generateConfigFile = (
-  results: Record<string, unknown>,
+  results: PromptsResults,
   generateEsm = false,
 ): string => {
   const {useTypescript, coverage, coverageProvider, clearMocks, environment} =

packages/create-jest/src/index.ts

@@ -0,0 +1,8 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+export {runCreate, runCLI} from './runCreate';