Enzyme vs react testing library on calling useEffect

enzyme-vs-react-testing-library-use-effect.tsx

export const usePolling = ({ pollFn, interval }: Params, deps: any[]) => {
  useEffect(() => {
    let timeout: number | undefined;
    let isMounted = true;

    const poller = async () => {
      await pollFn();

      // only do next polling if the function is still mounted
      // i.e. it hasn't been replaced by new function because `deps` change
      if (isMounted) {
        timeout = window.setTimeout(() => {
          poller();
        }, interval);
      }
    };

    poller();

    return () => {
      isMounted = false;
      window.clearTimeout(timeout);
    };
  }, deps);
};

// For above hook

// This is for react testing library
test('testing library', () => {
  const pollFnSpy = jest.fn().mockReturnValue(Promise.resolve());

  const TestComponent = ({ dep }: { dep: string }) => {
    usePolling(
      {
        pollFn: () => pollFnSpy(dep),
        interval: 5000,
      },
      [dep],
    );
    return null;
  };

  const { rerender, unmount } = render(<TestComponent dep="value-1" />);
  expect(pollFnSpy).toHaveBeenNthCalledWith(1, 'value-1'); // instantly after render
});

// This is for enzyme
test('enzyme', () => {
   const pollFnSpy = jest.fn().mockReturnValue(delay(10));

    const TestComponent = () => {
      usePolling(
        {
          pollFn: pollFnSpy,
          interval: 5,
        },
        [],
      );
      return null;
    };

    const wrapper = mount(<TestComponent />);
    jest.advanceTimersByTime(1000); // need to wait
    expect(pollFnSpy).toHaveBeenCalledTimes(1);
});