Kata

Random tests go up to 999, but description promises us 10_000 ( use mapSize (* 100) $ property $ \ (Positive n) -> do to get that and automatic shrinking ).

A white kata should show inputs on test failure ( use Test.HUnit.assertEqual for that ).

I must've misread the input limits. That's been updated. Fork here

Also, is it preferred to show inputs differently than the way QuickCheck displays them, like below?

Falsifiable (after 1 test):
  Positive {getPositive = 1}
expected: 0
 but got: -1

The way QuickCheck show them is not ideal, fully agree. All the alternatives ( that still do shrinking ) are a lot more work though. If I really want nice messages, I just forgo shrinking. ( But shrinking is just so nice to have! :)