Jest spyOn with uuid breaking in 8.x

Question

I have a jest spyOn with the uuid which was working in the version 3.4.0 after upgrading it to 8.3.2 the test breaks with the error Cannot spyOn on a primitive value; undefined given

import uuid from 'uuid';
jest.spyOn(uuid, 'v4');

Answer 1

The best way to mock uuid lib version 8.x is using Mocking Partials:

jest.mock( 'uuid', () => ({
  v4: jest.fn(() => '1234567890' )
}));

Answer 2

You need to change the way you import uuid

import { v4 as uuidv4 ) from uuid;

https://github.com/uuidjs/uuid#readme