In my experience, types (at least in the kinds of languages I like) and tests are orthogonal, though people enamored of either often try to use it to do the wor

In my experience, types (at least in the kinds of languages I like) and tests are orthogonal, though people enamored of either often try to use it to do the work the other is best at. I both TDD and TDD: that is, I do both type-driven and test-driven development, and the combo is incredible. I strongly suspect that if and as I’m able to add tools like formal methods, logic programming, etc. to my tool belt they will similarly become orthogonal tools for correctness that I can employ where appropriate.