With property-based testing one can describing the behavior over the entire domain(s) of valid inputs. Sampling is used to draw a set of cases to actually test,

With property-based testing one can describing the behavior over the entire domain(s) of valid inputs. Sampling is used to draw a set of cases to actually test, up to a certain number of test. Knowledge about boundary conditions in the domain can help catching failures earlier, though plain random seems to be pretty darn effective (at least for code written by humans). Candidates with dead code should maybe be punished. Candidates with higher complexity should maybe be punished.