https://codesandbox.io/s/upbeat-frost-3tt25

1. Press Suspend, see "Loading..."
2. Wait five seconds, you'll see "Happy birthday" at some point 
3. You won't see it again no matter how long you wait

Expected: you'll see it every five seconds.
expect(Scheduler).toFlushAndYield([
      
      'Suspend! [A]',
      'Loading...',
    ]);
    
    expect(ReactNoop.getChildren()).toEqual([]);
    
    Scheduler.unstable_advanceTime(450);
    await advanceTimers(450);
    
    
    expect(Scheduler).toFlushWithoutYielding();
    expect(ReactNoop.getChildren()).toEqual([]);
    
    Scheduler.unstable_advanceTime(500);
    await advanceTimers(500);
    
    expect(Scheduler).toFlushWithoutYielding();
    expect(ReactNoop.getChildren()).toEqual([span('Loading...')]);
    
    Scheduler.unstable_advanceTime(4500);
    await advanceTimers(4500);
    
    expect(Scheduler).toHaveYielded(['Promise resolved [A]']);
    expect(Scheduler).toFlushAndYield(['A']);
    expect(ReactNoop.getChildren()).toEqual([span('A')]);
  });
  it('does not suspends if a fallback has been shown for a long time', async () => {
    function Foo() {