Agreed: tests only test for discrete "points" of the input space (even with things like hypothesis testing and randomized input testing), and in general, in pur

Agreed: tests only test for discrete "points" of the input space (even with things like hypothesis testing and randomized input testing), and in general, in pure TDD, it is sufficient to test for one each of the class of points (eg. only one negative case to ensure negative part of the code is triggered). But we should not forget we are all working against legacy code bases and libraries outside our control, and sometimes, tests might be the best available tool for achieving something other than their primary purpose, which I'd happily accept as a fun hack.