feat(cli): config:init makes mjs config when using ESModules

src/cli/cli.spec.ts

@@ -33,12 +33,6 @@ const runCli = async (
 let mockedProcess: any
 const FAKE_CWD = normalize('/foo/bar')
 const FAKE_PKG = normalize(`${FAKE_CWD}/package.json`)
-fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-fs.readFileSync.mockImplementation((f): any => {
- if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
- throw new Error('ENOENT')
-})
 
 // === test ===================================================================
 
@@ -65,7 +59,14 @@ afterEach(() => {
 
 describe('cli', () => {
  it('should output usage', async () => {
+ fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fs.readFileSync.mockImplementation((f): any => {
+ if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+ throw new Error('ENOENT')
+ })
  expect.assertions(2)
+
  await expect(runCli()).resolves.toMatchInlineSnapshot(`
  {
  "exitCode": 0,
@@ -121,9 +122,17 @@ describe('config', () => {
  'ts',
  '--babel',
  ]
+
  it('should create a jest.config.json (without options)', async () => {
+ fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fs.readFileSync.mockImplementation((f): any => {
+ if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+ throw new Error('ENOENT')
+ })
  expect.assertions(2)
  const res = await runCli(...noOption)
+
  expect(res).toEqual({
  exitCode: 0,
  log: '',
@@ -143,9 +152,17 @@ module.exports = {
  ],
  ])
  })
+
  it('should create a jest.config.foo.json (with all options set)', async () => {
+ fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fs.readFileSync.mockImplementation((f): any => {
+ if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+ throw new Error('ENOENT')
+ })
  expect.assertions(2)
  const res = await runCli(...fullOptions, 'jest.config.foo.js')
+
  expect(res).toEqual({
  exitCode: 0,
  log: '',
@@ -172,9 +189,17 @@ module.exports = {
  ],
  ])
  })
+
  it('should update package.json (without options)', async () => {
+ fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fs.readFileSync.mockImplementation((f): any => {
+ if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+ throw new Error('ENOENT')
+ })
  expect.assertions(2)
  const res = await runCli(...noOption, 'package.json')
+
  expect(res).toEqual({
  exitCode: 0,
  log: '',
@@ -199,8 +224,15 @@ Jest configuration written to "${normalize('/foo/bar/package.json')}".
  })
 
  it('should update package.json (with all options set)', async () => {
+ fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fs.readFileSync.mockImplementation((f): any => {
+ if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+ throw new Error('ENOENT')
+ })
  expect.assertions(2)
  const res = await runCli(...fullOptions, 'package.json')
+
  expect(res).toEqual({
  exitCode: 0,
  log: '',
@@ -230,8 +262,16 @@ Jest configuration written to "${normalize('/foo/bar/package.json')}".
  ],
  ])
  })
+
  it('should output help', async () => {
+ fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fs.readFileSync.mockImplementation((f): any => {
+ if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+ throw new Error('ENOENT')
+ })
  const res = await runCli('help', noOption[0])
+
  expect(res).toMatchInlineSnapshot(`
  {
  "exitCode": 0,
@@ -259,7 +299,37 @@ Jest configuration written to "${normalize('/foo/bar/package.json')}".
  }
  `)
  })
- }) // init
+
+ it('should create jest config with type "module" package.json', async () => {
+ fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fs.readFileSync.mockImplementation((f): any => {
+ if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0', type: 'module' })
+ throw new Error('ENOENT')
+ })
+ expect.assertions(2)
+ const res = await runCli(...noOption)
+
+ expect(res).toEqual({
+ exitCode: 0,
+ log: '',
+ stderr: `
+Jest configuration written to "${normalize('/foo/bar/jest.config.js')}".
+`,
+ stdout: '',
+ })
+ expect(fs.writeFileSync.mock.calls).toEqual([
+ [
+ normalize('/foo/bar/jest.config.js'),
+ `/** @type {import('ts-jest').JestConfigWithTsJest} */
+export default {
+ preset: 'ts-jest',
+ testEnvironment: 'node',
+};`,
+ ],
+ ])
+ })
+ })
 
  describe('migrate', () => {
  const pkgPaths = {

src/cli/config/init.ts

@@ -108,12 +108,14 @@ export const run: CliCommand = async (args: CliCommandArgs /* , logger: Logger *
  body = JSON.stringify({ ...pkgJson, jest: jestConfig }, undefined, ' ')
  } else {
  // js config
- const content = []
+ const content: string[] = []
  if (!jestPreset) {
  content.push(`${preset.jsImport('tsjPreset')};`, '')
  }
  content.push(`/** @type {import('ts-jest').JestConfigWithTsJest} */`)
- content.push('module.exports = {')
+ const usesModules = pkgJson.type === 'module'
+ content.push(usesModules ? 'export default {' : 'module.exports = {')
+
  if (jestPreset) {
  content.push(` preset: '${preset.name}',`)
  } else {