If you only write tests for things that won’t fail, you’re doing it wrong. Are you anticipating some other feature coming soon? Write a failing test for it. Did you find untested code that might run soon with a little work? Write a test for it. Did a nonessential feature break while adding an essential feature, let the test fail and fix it later.

My favorite messages are “Don’t touch this file unless you talk to Gary. Don’t import this file unless you talk to Gary. Don’t even think about this file until you talk to Gary!” And Gary has moved on and hasn’t worked there for years.

All yaml is just sparkling JSON.