jest mock mockname

test("mockFn.mockReset", () => {
  const mockFn = jest.fn().mockImplementation(() => 43);
  const MockClass = jest.fn();

  new MockClass();
  expect(mockFn()).toBe(43);

  expect(mockFn.mock.calls).toHaveLength(1);
  expect(MockClass.mock.instances).toHaveLength(1);

  mockFn.mockReset();
  MockClass.mockReset();

  new MockClass();
  expect(mockFn()).toBeUndefined();

  expect(mockFn.mock.calls).toHaveLength(1);
  expect(MockClass.mock.instances).toHaveLength(1);
});

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

test("mock.calls", () => {
  const mockFn = jest.fn();
  mockFn(1, 2);

  expect(mockFn.mock.calls).toEqual([[1, 2]]);
});