I'd recommend watching this https://www.youtube.com/watch?v=zi0rHwfiX1Q to see how powerful this can be.

I've just discovered generative testing due to clojure.spec. Describing specs for your data works not only to help validate data structures but can be plugged in as properties for generative testing.

After the "aha" moment it was followed by a feeling that I've wasted so much time writing specs just to validate data structures and writing specs just to see if my functions are working as they should.

This is one of the things I wish was obvious in my learning track right after vim/emacs will help you code faster.