Also, if there are input values of the right type that cannot be handled properly, that should also be tested! That is the kind of thing tests are for!
Example: you write a function that divides two numbers. It's not possible to divide by zero. You should absolutely have a test that passes in a divisor of zero and asserts that some kind of custom DivideByZeroException is thrown. If you know that certain inputs are out of range, you should test them explicitly -- otherwise you're being sloppy. If there is a large number of inputs out of range, you should test all of them, and you can use a `for` loop if you have to.
The difference is, if you have a valid input out of range, that is all you need to test -- the language itself takes care of all the "wrong type" tests for you. Otherwise you have to write them yourselves, and if you don't, you don't actually have good coverage. I understand that it is customary in dynamic languages to not write those tests, but that is merely another argument for the superiority of static typing.