Hedgehog is a brand new property-based testing system.

In mainstream scenarios it

  • makes properties less fragmented
  • doesn’t require to write shrinkers; it does it for free
  • provides fine-grained control over the scope and shrinking of generated values

It is available for

  • Haskell
  • F#
  • Scala (plannned)
  • PureScript (planned)

It can be used from

Jacob Stanley, the creator of Hedgehog, made yesterday an announcement on Haskell Reddit and overall received interesting feedback, including one from Koen Claessen1.


  1. Koen Claessen created QuickCheck together with John Hughes.