Jest

Links

• Mocking Node modules

• mockFn.mockClear

• mockFn.mockReset

• expect.anything()

Asynchronous or time-based events (timers)

describe('do some crazy stuff with timers.', () => {
  beforeEach(() => {
    // declare the intent of using timers
    jest.useFakeTimers()
  })

 it('should .', () => {
    // mock if needed
    const callback = jest.fn()

    // mount component

    // follow by expect before timers

    // execute timers
    jest.runAllTimers()

    // expect something after timers have been executed
    expect(callback).toHaveBeenCalledTimes(1)
  })

Verify that function was called with multiple arguments

.toHaveBeenCalledWith(arg1, arg2, ...)

Also available under the alias: .toBeCalledWith()

Verify that the same function was called multiple times with different arguments

it('should be able to change access rights.', () => {
  expect(onUpdateAccess).not.toBeCalled()

  const newAccess = {
    ...report.access,
    view: {
      type: 'user',
      id: '3',
    },
  }

  component.find(Rights).prop('onChange')(newAccess)

  expect(onUpdateAccess).toBeCalledTimes(2)
  expect(onUpdateAccess).toBeCalledWith('edit', newAccess.edit)
  expect(onUpdateAccess).toBeCalledWith('view', newAccess.view)
})