Clean hlint and cabal warnings

test/AFRPSpec.hs

@@ -19,6 +19,7 @@ import qualified Hedgehog.Gen as Gen
 import qualified Hedgehog.Range as Range
 import Test.Hspec
 import Test.Hspec.Hedgehog
+import Data.Maybe (listToMaybe)
 
 fakeRequest :: Request
 fakeRequest = Request (sec 0) utc nil "test"
@@ -52,7 +53,7 @@ instance Functor St where
   fmap f (St g) = St $ \s -> let (a, s') = g s in (f a, s')
 
 instance Applicative St where
-  pure a = St (\s -> (a, s))
+  pure a = St (a,)
   St f <*> St x = St $ \s -> let (f', s') = f s; (a, s'') = x s' in (f' a, s'')
 
 instance Monad St where
@@ -165,7 +166,7 @@ lMergeSpec = describe "lMerge" $ do
 changesSpec :: Spec
 changesSpec = describe "changes" $ do
   it "first output is always Tick" $
-    runPure changes "hello" !! 0 `shouldBe` Tick
+    listToMaybe (runPure changes "hello") `shouldBe` Just Tick
 
   it "outputs Event only on value change" $
     runPure changes "aaaabbbcca"