Only illegal immigrant fears of being tested... because it could be their end of staying.
From what I know, every time you go to the public space in China...
There's an ID check-up, to check people's mobility for coronavirus tracing system.
The problem with foreigners, what they have is a passport and mostly get rejected or denied to enter.
I guess this is what some of the Africans don't understand, they feel they are discriminated against or something.
But this kind of system for just checking local people ID also has advantages and drawbacks as well.
The advantages, you can reduce the number of people visits some public places, which means less risk for coronavirus spreading.
The drawback, what if one of the foreigners got coronavirus and since you didn't trace them, there's a black hole of where they went in the past.