Using requireActual isn't requiring the actual version of module, in a Jest test

user_420217 0
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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 comment 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?

jestjs node.js mocking unit-testing javascript
1 Answers

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')
  const utils = require.requireActual('./utils')

  // `utils` is now the original version of that module
  expect(utils.getImage('note.png')).toBe('note')
})
user_103117620
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