alt Hacker NewsTest cases are an indicator. They say that this situation I thought of works as I think it should. It doesn't cover everything, but it does cover a large number of things.
A test is mostly useful only in the case that by failing it alerts you to a bug.
They don't say that because you didn't write the tests, AI did, so who knows what behaviors it thought of and wrote tests for. That's the reason these type of metrics are very bad, especially in this context when bad tests are easier to write