> where I have test suits and where I can be totally confident, that everything has a well defined spec of what it should do and where I can't break something a

> where I have test suits and where I can be totally confident, that everything has a well defined spec of what it should do and where I can't break something accidentally without noticing it I'm often in the middle. Where I have tests, they're not always (or rarely) the result of a "well defined spec". But... the tests do reference whatever the understanding of XYZ was at that time. That's often as well-defined as I can get. Clients will come back months later and say "this is broken". Well, no it's not. The tests work just fine. "No, that's wrong, it's not supposed to work that way". Well.. there's a test with notes indicating "do ABC then XYZ" and the test ensures that's working based on what was known/agreed on at that time. That's often not the same as "well defined" by a long shot.