I am generally against the brainless insistence on just writing tests without thinking about the value vs cost (especially on unit tests, which are usually the

I am generally against the brainless insistence on just writing tests without thinking about the value vs cost (especially on unit tests, which are usually the lowest value and highest cost IMO), but I have found them extremely valuable on occasion. Sometimes for being able to hammer some bit of tricky code through a bunch of different scenarios while figuring out the edge cases, others for validating top-level requirements, and especially for helping prevent regressions while making other changes (which will 100% happen once you have more than one person working on a more than trivial codebase).