Static types most definitely do not replace the need for tests!
In retrospect, my original response was too terse. Static typing and testing serve the same purpose, which is to make sure your application runs according to some measure of correctness. We shouldn't be setting up one-or-the-other dichotomies — we can have both!
Static types won't help with your application logic, but they will (for example) ensure your function inputs and outputs are the correct types, help document your code and ensure consumers call your code correctly. Unit tests can only do the first one, and it's more verbose and brittle.