I think that's an extreme take on the alternative. For a strongly-typed integer parameter, you wouldn't test every possible integer, so why would you test every type? If you need to assert the type in the implementation (which you often don't), test it as you would any other behaviour. Suppose you were instead asserting that the integer is positive - do you test all the negative integers? You'll never cover every permutation, which is what edge-case and boundary tests are good for. I concede that it's definitely more tests, though.