I have a Jest test file like the following:

// utils.test.js
let utils = require('./utils')

jest.mock('./utils')

test('print items', () => {
  utils.printItems(['a'])
  expect(utils.getImage).toHaveBeenLastCalledWith('a.png')
})

test('get image', () => {
  utils = require.requireActual('./utils')

  // `utils` is still mocked here for some reason.
  expect(utils.getImage('note.png')).toBe('note')
})

And a mock like this:

// __mocks__/utils.js
const utils = require.requireActual('../utils');

utils.getImage = jest.fn(() => 'abc');

module.exports = utils;

Yet as you can see in my ment in the second test, utils is still the mocked version rather than the actual version of the module. Why is that? How can I get it to be the actual version, rather than the mocked version?

I have a Jest test file like the following:

// utils.test.js
let utils = require('./utils')

jest.mock('./utils')

test('print items', () => {
  utils.printItems(['a'])
  expect(utils.getImage).toHaveBeenLastCalledWith('a.png')
})

test('get image', () => {
  utils = require.requireActual('./utils')

  // `utils` is still mocked here for some reason.
  expect(utils.getImage('note.png')).toBe('note')
})

And a mock like this:

// __mocks__/utils.js
const utils = require.requireActual('../utils');

utils.getImage = jest.fn(() => 'abc');

module.exports = utils;

Yet as you can see in my ment in the second test, utils is still the mocked version rather than the actual version of the module. Why is that? How can I get it to be the actual version, rather than the mocked version?

• javascript
• node.js
• unit-testing
• mocking
• jestjs

• 1 jest.isMockFunction is helpful for not running a test if the function isn't mocked the way you expect – jcollum Commented Sep 3, 2021 at 18:20

1 Answer 1

You still get the mocked utils module in your second test because you have actually required it inside the manual mock (__mocks__/utils.js), which in Jest's cache is still referenced as a mock that should be returned due to jest.mock() being at the top most scope.

A way to fix it is either to not use the module in a manual mock, or update your second test to unmock and require a new version of it. For example:

test('get image', () => {
  jest.unmock('./utils')
  jest.resetModules()
  const utils = require.requireActual('./utils')

  // `utils` is now the original version of that module
  expect(utils.getImage('note.png')).toBe('note')
})