It would add tests for exact error messages, for example. It would add tests that the process exited with very specific error codes. Basically tests that I would never ever write myself.

And yes everyone works in different domains. I work at a database vendor myself, so mostly lower-level work.

I’m very happy and successful with LLMs, I just don’t think that these “just move all your tests to your type system!” or “get 100% test coverage” rules are an answer in the long term as we haven’t yet figured out how to do this well.

I personally treat tests as components that need to be well architected, maintained, and adding them risks increasing technical debt and needs to be treated as such.

That feels like a pretty uncharitable interpretation of my original comment.

I was describing general strategy, that when applied in concert is more than the sum of its parts.

E.g I mentioned property-based testing, that is another angle at which a test avoids assertions that are too fine grained.