Test.purs

module Test where

import Control.Monad.Aff         (Aff, runAff)
import Control.Monad.Eff         (Eff)
import Control.Monad.Eff.Console (CONSOLE, log)
import Prelude                   ((<>), bind, pure, unit)

type MonadA m
  = { opA :: m String
    }

monadA :: forall eff. MonadA (Eff (console :: CONSOLE | eff))
monadA
  = { opA: do
        log "opA WOOP"
        pure "opA Result"

    }

type MonadB m
  = { opB :: m String
    }

monadB :: forall eff. MonadB (Eff eff)
monadB
  = { opB: pure "opB Result"
    }

affMonadB :: forall eff. MonadB (Aff eff)
affMonadB
  = { opB: pure "opB Aff Result"
    }

type TestProps eff
  = { someMonadA  :: MonadA (Eff eff)
    , someMonadB  :: MonadB (Aff eff)
    }

foreign import data SomeEff :: !

foreign import someThingArbitrary
  :: forall eff.
     (String -> Eff (someEff :: SomeEff | eff) String)
  -> Eff eff String

thisWorks :: forall eff.
             TestProps eff
          -> Eff eff String

thisWorks props
  = do
      s1 <- someThingArbitrary \s -> pure s
      s2 <- props.someMonadA.opA
      pure (s1 <> s2)

thisFails :: forall eff.
             TestProps eff
          -> Eff eff String

thisFails props
  = do
      someThingArbitrary \_ ->
        props.someMonadA.opA