covid test to enter in China? Still?

HI! I wanted to organize a trip to Shanghai for May, but I didn't understand how the rules regarding covid work. here in Italy they told me that before leaving I still have to take the test, so I asked if there were still quarantines in China, but they told me that quarantines no longer exist in China .but if there are no more quarantines why do I still have to take the test? and if by chance I test positive in China what will happen to me? I thought there was no need to test anymore. moreover, travelers who enter Italy from China do not have to take any tests, but then why do I, an Italian, have to do it to enter China?
The problem is that I want to go back to visit China, but if I have to spend money and then find myself locked up in a hotel....
I hope I have misunderstood the regulation for the entry of tourists into China, can you explain me?