Difference between resetAllMocks, resetModules, resetModuleRegistry, restoreAllMocks in Jest Ask Question

The following sections explain the behaviors of each function and its corresponding config directive. In the case of config directives, the explained behavior takes place in between each test making them more and more isolated from the other tests.

References to fn are implying a sample jest mock function under each of these actions.

jest.clearAllMocks() and clearMocks:[boolean]

Resets all the mocks usage data, not their implementation. In other words, it only replaces fn.mock.calls and fn.mock.instances properties of a jest mock function.

jest.resetAllMocks() and the resetMocks:[boolean]

A superset of clearAllMocks() which also takes care of resetting the implementation to a no return function. In other words, it will replace the mock function with a new jest.fn(), not just its fn.mock.calls and fn.mock.instances.

jest.restoreAllMocks() and restoreMocks:[boolean]

Similar to resetAllMocks(), with one very important difference. It restores the original implementation of "spies". So, it goes like "replace mocks with jest.fn(), but replace spies with their original implementation".

So, in cases where we manually assign things with jest.fn() (not spies), we have to take care of implementation restoration ourselves as jest won't be doing it.

jest.resetModules() and resetModules:[boolean]

これは、すべての必須/インポートされたモジュールのキャッシュである Jest のモジュール レジストリをリセットします。Jest は、これを呼び出した後、必要なモジュールを再インポートします。他のテストでモック化されたすべてのモジュールを処理する必要がない、まっさらな状態を想像してください。

jest.resetModuleRegistry

これは の別名ですresetModules。以下を参照してください。
https://github.com/facebook/jest/blob/7f69176c/packages/jest-runtime/src/index.ts#L1147

まとめ

この表は概要を示しています。左の列は実行するテストの種類です。

クリア、リセット、復元の動作の違いを確認します。
https://repl.it/@sepehr/jest-mock-api-reset-restore#jest-mock-apis.test.js

PASS  ./jest-mock-apis.test.js

jest mock reset/restore api
  when calling mockReset() on a test double with custom impl.
    if the test double is a spy
      ✓ jest replaces the impl. to a new undefined-returning jest.fn() (18ms)
    if the test double is "not" a spy
      ✓ jest replaces the impl. to a new undefined-returning jest.fn() (17ms)

  when calling mockRestore() on a test double with custom impl.
    if the test double is "not" a spy
      ✓ jest resets the impl. to a new undefined-returning jest.fn() (2ms)
    if the test double is a spy
      ✓ jest restores the original impl. of that spy (7ms)

describe('jest mock reset/restore api', () => {
  
  describe('when calling mockReset() on a test double with custom impl.', () => {
    describe('if the test double is a spy', () => {
      test('jest replaces the impl. to a new undefined-returning jest.fn()', () => {
        const module = { api: () => 'actual' }
        jest.spyOn(module, 'api').mockImplementation(() => 'spy mocked')
        
        expect(module.api()).toStrictEqual('spy mocked')
        expect(module.api).toHaveBeenCalledTimes(1)

        module.api.mockReset()

        expect(module.api()).toStrictEqual(undefined)
        expect(module.api).toHaveBeenCalledTimes(1)
      })
    })
    

    describe('if the test double is "not" a spy', () => {
      test('jest replaces the impl. to a new undefined-returning jest.fn()', () => {
        const api = jest.fn(() => 'non-spy mocked')
        
        expect(api()).toStrictEqual('non-spy mocked')
        expect(api).toHaveBeenCalledTimes(1)

        api.mockReset()

        expect(api()).toStrictEqual(undefined)
        expect(api).toHaveBeenCalledTimes(1)
      })
    })
  })

  describe('when calling mockRestore() on a test double with custom impl.', () => {
    describe('if the test double is "not" a spy', () => {
      test('jest resets the impl. to a new undefined-returning jest.fn()', () => {
        const api = jest.fn(() => 'non-spy mocked')
        
        expect(api()).toStrictEqual('non-spy mocked')
        expect(api).toHaveBeenCalledTimes(1)

        api.mockRestore()

        expect(api()).toStrictEqual(undefined)
        expect(api).toHaveBeenCalledTimes(1)
      })
    })

    describe('if the test double is a spy', () => {
      test('jest restores the original impl. of that spy', () => {
        const module = { api: () => 'actual' }
        jest.spyOn(module, 'api').mockImplementation(() => 'spy mocked')
        
        expect(module.api()).toStrictEqual('spy mocked')
        expect(module.api).toHaveBeenCalledTimes(1)

        module.api.mockRestore()

        expect(module.api()).toStrictEqual('actual')
        expect(module.api).not.toHaveProperty('mock')
      })
    })
  })
})