I'm not sure this is correct. The REPL 'phase' of feature development tends to be useful before you want to ossify things in tests; it's excellent for explorato

I'm not sure this is correct. The REPL 'phase' of feature development tends to be useful before you want to ossify things in tests; it's excellent for exploratory thinking, and it encourages you to build a small suite of tools and state to tinker with, whereas tests cut through to use the minimal required tools and state to formulate the completed, trimmed down thought.