Unit testing may catch some of the mismatches, but testing is almost always a probabilistic rather than a deterministic process. Testing is a poor substitute for proof. - Bartosz Milewski
Lean Testing or Why Unit Tests Are Worse Than You Think
https://evanfarrer.blogspot.com/2012/06/unit-testing-isnt-enough-you-need.html
https://kentcdodds.com/blog/write-tests?gi=556c9e13007f
https://web.archive.org/web/20180716060642/http://250bpm.com/blog:40
https://www.youtube.com/watch?v=Fha2bVoC8SE