11/06/2025

If you are the kind of person who values certainty over flexibility, you’ll likely use a lot of spies in your tests and you’ll tolerate the inevitable fragility. If, however, you are the kind of person who values flexibility over certainty, you’ll be more like me. You’ll prefer value and property tests over spies, and you’ll tolerate the nagging uncertainty.

— Robert C. Martin, Clean Craftsmanship