> I don't think they necessarily are good to validate work though, or at least, they do so poorly. For me, I've found they actually do help significantly to ca

> I don't think they necessarily are good to validate work though, or at least, they do so poorly. For me, I've found they actually do help significantly to catch bugs even for my initial PRs. To know your code works, you either have to run it manually or else write a unit test, and you must do so for all relevant code paths. How much time do you save by avoiding the unit test, if any at all, and how long before you recoup that time via your integral? In some projects, I think the time saved is closed to zero, whereas the benefits accrue almost immediately. You are right that there is a tradeoff here, and I have been part of a project where I wrote a bunch of tests for code that ended up being a throwaway prototype. You could argue that I wasted time and resources there. On the other hand, I've seen more prototypes get shipped to production than scrapped, so maybe the calculated risk is worth it even in scrappier contexts.