Use QuickCheck generators in Hedgehog and vice versa.

Use QuickCheck generators in Hedgehog and vice versa.

Hedgehog is a modern property-based testing system, in the spirit of QuickCheck. Hedgehog uses integrated shrinking, so shrinks obey the invariants of generated values by construction.

To get started quickly, see the examples: <https://github.com/hedgehogqa/haskell-hedgehog/tree/master/hedgehog-

hedgehog-quickcheck [![Hackage][hackage-shield]][hackage]

Hedgehog will eat all your bugs.

Use QuickCheck generators in Hedgehog and vice versa.

Example

The Hedgehog.Gen.QuickCheck module allows the use of QuickCheck generators inside Hedgehog.

{-# LANGUAGE TemplateHaskell #-}

import           Hedgehog
import qualified Hedgehog.Gen as Gen
import qualified Hedgehog.Gen.QuickCheck as Gen
import qualified Hedgehog.Range as Range

Once you have your imports set up, you can write a property which mixes QuickCheck and Hedgehog generators together:

prop_reverse :: Property
prop_reverse =
  property $ do
    xs <- forAll $ Gen.list (Range.linear 0 100) (Gen.arbitrary :: Gen Char)
    reverse (reverse xs) === xs

And add the Template Haskell splice which will discover your properties:

tests :: IO Bool
tests =
  checkParallel $$(discover)

You can then load the module in GHCi, and run it:

λ tests
━━━ Test.Example ━━━
  ✓ prop_reverse passed 100 tests.