Is scalacheck non-deterministic approach problematic?

Question

I know I can make scalacheck tests deterministic, but I have a more general question: does the default non-deterministic behaviour of scalacheck cause practical problems? I've always thought that the tests should be deterministic and repeatable, and the other way around signals a bad tests design. Scalacheck seems to be used in a couple of "serious" projects, so I'm wondering whether breaking this deterministic principle is or is not in fact a real-life (not only theoretical) problem?

Answer 1

I'd say that "tests should be deterministic and repeatable" doesn't always apply. They obviously have their rather large place, but randomized testing is useful as well. In addition to QuickCheck/ScalaCheck and friends there are approaches such as fuzzing.