[berkes]

I do test manually when the author does not practice TDD. (Or if there aren't tests.)

Additional benefit is that this shows to devs and management what a time saver TDD and testing in general is. It shows immediately that lacking tests cost valuable, senior, time, rather than save time by not writing tests.

It also is simply needed: when there are no tests, we'll need to manually verify and check for regressions.