Test async act

test-async-act.js

it('should render with the correct text with sync act', () => {
  act(() => {
    ReactDOM.render(<AsyncApp/>, el);
  });
  expect(el.innerHTML).toContain('unloaded val');
});

it('should render with the correct text with async act', async () => {
  await act(async () => {
    ReactDOM.render(<AsyncApp/>, el);
  });
  expect(el.innerHTML).toContain('fetched val');
});