Right. You mean all behaviors are tested, essentially.
So if you / team are going to implement a new feature, what does that look like? Do you write Gherkin or similar, unit tests or both? Can you provide an example of what that might look like? How much of this has changed for you since the pre-AI days?
These days, yes, integration test at the high level (usually a 1-to-3 liner), then unit tests as I go, often some mocked functional tests. This is basically the same but a ton faster in the AI days, you have to hold the AI accountable and demand quality and iterate, but this weekend I've built an entire test suite for a monorepo I just started working on. It's garbage quality but better than no tests, of course, and will improve as I work.
You can find some open source examples on github, either directly https://github.com/pgdogdev/pgdog/commits/main/?author=jagge... or through my profile - that repo has a pure-sql integration suite I wrote essentially entirely with AI: https://github.com/pgdogdev/pgdog/tree/main/integration/sql
There's also older work on github you can see over the years, a mishmash and grab bag, I would prefer if more of my work were open source but somehow most employers still default to closed source
Edit: While I'm thinking about it, the other thing you can do with AI is demand that it TDD things - I'm more of a "test all the fucking time" adherent, I don't care whether the tests are written first, but AI is perfectly happy to skate by making a tautological test unless you make it write the test first, ensure it fails correctly, make your change, and don't let it modify the test.