create mock functions jest code example

Example 1: how to mock a library in jest

import randomColor from "randomcolor";


jest.mock("randomColor", () => {
  return {
    randomColor: () => {
      return mockColor('#123456');
    }
  }
});
let mockColor = jest.fn();

Example 2: jest mock mockname

test("mockName", () => {
  const mockFn = jest.fn().mockName("mockedFunction");
  mockFn(); // comment me
  expect(mockFn).toHaveBeenCalled();
});