>Are people reviewing all the tests that have been created automatically?

No.

> How do we make sure that AI does not fake them by silently (by silent changes or by faking the test output)?

I have never seen this happen for a couple of months at least.

That's a big issue in my team. We cannot really review tests manually, we already have too much just reviewing the code. And even then, sometimes the 'is this change necessary' question is forgotten or ignored (happened to me 20 minutes ago) because I an tired of fighting my junior+AI. I try to make AI refactor the tests every weeks ande that's it.

> Are people reviewing all the tests that have been created automatically?

Absolutely not! Some people ask a code assistant to write only integration/end-to-end tests and commit them. Unittests is only to help LLM generate correct code.

Yes, but periodic audits.