mock mutation observer and use on jest test

testing-mutation-observer-2.test.js

const mockMutationObserver = function() {
  observerDomChangesCaf.mockImplementation((_, errorCallback) => {
    console.log('observerDomChangesCaf');
    errorCallback();
  });

  const el = document.createElement('div');

  useMutationObserver.mockImplementation((_, callback) => {
    const mut = new MutationObserver(callback);

    mut.observe(el, {attributes: true});
  });

  const triggerMutation = () => el.style.display = 'flex';

  return triggerMutation;
};

it.only('should emit capture-error event on error', async () => {
  const triggerMutation = mockMutationObserver();
  // gen.then((fn1) => {
  //   console.log('inside then');
  //   triggerMutation = fn1
  // });
  const imageUrl = 'https://url-image.com';

  wrapperCaptureFrameSpy.mockImplementation(() => imageUrl);

  // mockMutationObserver();

  const { emitted } = renderWidgetCapture({
    step: 0,
    documentType: 'CNH',
    showCapture: true,
  });

  await flushPromises();

  const captureButton = screen.queryByTestId('captureButton');

  await fireEvent.click(captureButton);

  triggerMutation();

  await flushPromises();

  await waitFor(() => expect(emitted()['capture-error'][0])
    .toEqual([imageUrl]));
  // expect(wrapperCaptureFrameSpy).
});