The key is "the same kind of exhaustive unit testing". Unit tests can serve many purposes, in terms of raising your confidence that code is correct. In a lang

The key is "the same kind of exhaustive unit testing". Unit tests can serve many purposes, in terms of raising your confidence that code is correct. In a language with minimal static type checking, a big part of what a good unit test suite will be doing is checking type invariants. In a language where those type invariants are checked for you, you don't need those particular unit tests.