users/grfn/xanthous/test/Xanthous/RandomSpec.hs


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module Xanthous.RandomSpec (main, test) where
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import Test.Prelude
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import Control.Monad.Random
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import Xanthous.Random
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main :: IO ()
main = defaultMain test

test :: TestTree
test = testGroup "Xanthous.Random"
  [ testGroup "chooseSubset"
    [ testProperty "chooses a subset"
      $ \(l :: [Int]) (Positive (r :: Double)) -> randomTest $ do
        ss <- chooseSubset r l
        pure $ all (`elem` l) ss

    ]
  ]
  where
    randomTest prop = evalRandT prop . mkStdGen =<< arbitrary