polysemy-check-0.6.0.0: test/EquivSpec.hs

{-# LANGUAGE PartialTypeSignatures #-}

{-# OPTIONS_GHC -Wno-orphans             #-}
{-# OPTIONS_GHC -fplugin=Polysemy.Plugin #-}

module EquivSpec where

import Data.IORef (newIORef, readIORef)
import Polysemy
import Polysemy.Check
import Polysemy.State
import Test.Hspec
import Test.Hspec.QuickCheck
import Test.QuickCheck


spec :: Spec
spec = do
  prop "Pure state is equivalent to IO state" $ do
    s0 <- arbitrary
    pure $
      prepropEquivalent @'[State Int] @Int
        (runPureState s0)
        (runIOState s0)


runPureState :: Int -> Sem '[State Int] a -> IO (Int, a)
runPureState s = pure . run . runState s


runIOState :: Int -> Sem '[State Int, Embed IO] a -> IO (Int, a)
runIOState s sem = do
  ref <- newIORef s
  a <- runM . runStateIORef ref $ sem
  r <- readIORef ref
  pure (r, a)