The more devs you have on a project, the more testing becomes vital. If there are tests, you can work on the code with confidence that you aren't going to unwit

The more devs you have on a project, the more testing becomes vital. If there are tests, you can work on the code with confidence that you aren't going to unwittingly break things. Frankly, I think thorough testing makes my code better too. If you can't figure out how to test a function you just wrote, how are you going to get any real reuse out of it later? I don't do TDD, but often testing will lead me to refactor things to be clearer.