Static typing isn't bad, but it's only as good as the type system is strong and detailed. Haskell's QuickCheck doesn't understand biases or infinite-typed value

Static typing isn't bad, but it's only as good as the type system is strong and detailed. Haskell's QuickCheck doesn't understand biases or infinite-typed values. The Hypothesis strategy of Strategies (the design pattern) is far more useful for producing serious test suites, as less time has to be spent fretting about which invariants can be hoisted to the type system.