They've been reporting new cases (on worldometer) every day that I've looked. Now - there are times when I've looked and the numbers are 0 depending on when the day starts and when numbers are reported. But there has been something reported every day. The last couple of days have been fewer than 100 though.
Look - I know it's about testing to "confirm" a case. And it appears that China is either testing very little or just not reporting all of the numbers when they do.
But if we're being honest - there have been plenty of reports of the US not testing everyone initially either. So the US numbers are also somewhat inaccurate.
This is more about watching the numbers climb on worldometer and how quickly the US is ramping up testing and will be passing these two countries who are seen as some of the worst case scenarios - the two countries with the most confirmed cases in the world, for now. Whether the US ever passes China is "real" cases or not - we will pass them in confirmed cases reported to WHO.