[amw-zero]

That’s an interesting example, that’s exactly where you’re likely to find bugs - at boundary values. You should test those more than you should test the number 5.

This is exactly why unit testing gives a false sense of security. You’ve done a lot, you’ve written all kinds of tests - but at the end of the day, you don’t get a proportionate amount of confidence about the code because there are infinite more cases that you haven’t thought about.

[Supermancho]

In Java, if my function doesn't modify the int, there's no reason to test the boundaries, other than 0 if the int is used in a calculation. The type system doesn't solely determine what tests to write. Tests are inferred from a combination of type system, timings, statements and variable usage.