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Using QuickCheck with Hspec

You can use arbitrary QuickCheck properties with Hspec, but they must be of type {{'Property'|id}}. QuickCheck's {{'property'|id}} function can be used to turn anything that is a member of the {{'Testable'|id}} class into a {{'Property'|id}}. Here is an example:

describe "read" $ do
  it "is inverse to show" $ property $
    \x -> (read . show) x == (x :: Int)

{% example QuickCheck.hs %}

It's also possible to modify some of the arguments passed to the Quickcheck driver, namely: the maximum number of successes before succeeding, the maximum number of discarded tests per successful test before giving up and size of the test case:

import Test.Hspec.Core.QuickCheck (modifyMaxSize)

describe "read" $ do
  modifyMaxSize (const 1000) $ it "is inverse to show" $ property $
    \x -> (read . show) x == (x :: Int)