A fully evolved type system (e.g. Coq) overlaps with unit testing. But the vast majority of languages people actually use have only partial type systems that re

A fully evolved type system (e.g. Coq) overlaps with unit testing. But the vast majority of languages people actually use have only partial type systems that require unit tests to stand in where the type system is lacking. In practice, when you write those tests for where the type system is lacking, you end up also incidentally testing where there is type system coverage, so there likely isn't much for industry to talk about.