Use OverloadedRecordDot & NoFieldSelectors

app/Main.hs

@@ -180,7 +180,7 @@ main = do
     let renderContext = RenderContext {..}
     let status = Status Data.Set.empty
     let action = diff True (StorePath left) (OutputNames (Data.Set.singleton "out")) (StorePath right) (OutputNames (Data.Set.singleton "out"))
-    diffTree <- Control.Monad.State.evalStateT (Control.Monad.Reader.runReaderT (unDiff action) diffContext) status
+    diffTree <- Control.Monad.State.evalStateT (Control.Monad.Reader.runReaderT action.unDiff diffContext) status
     let diffTree' =
           transformDiff transformOptions diffTree
     renderDiff renderRunner renderContext diffTree'

nix-diff.cabal

@@ -31,6 +31,8 @@ common language
     LambdaCase,
     MultiWayIf,
     NamedFieldPuns,
+    NoFieldSelectors,
+    OverloadedRecordDot,
     OverloadedStrings,
     RecordWildCards,
   ghc-options:         -Wall

src/Nix/Diff.hs

@@ -90,7 +90,7 @@ data Orientation = Character | Word | Line
     underneath `/nix/store`, but this is the overwhelmingly common use case
 -}
 derivationName :: StorePath -> Text
-derivationName = Text.dropEnd 4 . Text.drop 44 . Text.pack . unsafeStorePathFile
+derivationName storePath = Text.dropEnd 4 (Text.drop 44 (Text.pack storePath.unsafeStorePathFile))
 
 -- | Group paths by their name
 groupByName :: Map StorePath a -> Map Text (Map StorePath a)
@@ -109,7 +109,7 @@ groupByName m = Data.Map.fromList assocs
     > /nix/store/${32_CHARACTER_HASH}-${NAME}.drv
 -}
 buildProductName :: StorePath -> Text
-buildProductName = Text.drop 44 . Text.pack . unsafeStorePathFile
+buildProductName storePath = Text.drop 44 (Text.pack storePath.unsafeStorePathFile)
 
 -- | Like `groupByName`, but for `Set`s
 groupSetsByName :: Set StorePath -> Map Text (Set StorePath)
@@ -157,7 +157,7 @@ readDerivation sp = do
 -- queried.
 readInput :: StorePath -> Diff (Derivation StorePath Text)
 readInput pathAndMaybeOutput = do
-    let (path, _) = List.break (== '!') (Store.unsafeStorePathFile pathAndMaybeOutput)
+    let (path, _) = List.break (== '!') pathAndMaybeOutput.unsafeStorePathFile
     if FilePath.isExtensionOf ".drv" path
     then readDerivation (StorePath path)
     else do

src/Nix/Diff/Render/HumanReadable.hs

@@ -40,7 +40,7 @@ newtype Render a = Render { unRender :: ReaderT RenderContext (Writer Text) a}
     )
 
 runRender :: Render a -> RenderContext ->  (a, Text)
-runRender render rc = runWriter $  runReaderT (unRender render) rc
+runRender render rc = runWriter $  runReaderT render.unRender rc
 
 runRender' :: Render () -> RenderContext -> Text
 runRender' render = snd . runRender render
@@ -56,7 +56,7 @@ echo text = do
 indented :: Natural -> Render a -> Render a
 indented n = local adapt
   where
-    adapt context = context { indent = indent context + n }
+    adapt context = context { indent = context.indent + n }
 
 data TTY = IsTTY | NotTTY
 

src/Nix/Diff/Transformations.hs

@@ -107,7 +107,7 @@ foldManyInputDerivationsAlreadyCompared dd = case dd of
        { inputsDiff =
            inputsDiff'
              { inputDerivationDiffs =
-                 helper [] (inputDerivationDiffs inputsDiff')
+                 helper [] inputsDiff'.inputDerivationDiffs
              }
        , ..
        }

src/Nix/Diff/Types.hs

@@ -54,7 +54,7 @@ instance Arbitrary TextDiff where
   arbitrary = TextDiff <$> listOf arbitraryItem
 
 instance ToJSON TextDiff where
-  toJSON = listValue itemToJSON . unTextDiff
+  toJSON textDiff = listValue itemToJSON textDiff.unTextDiff
 
 instance FromJSON TextDiff where
   parseJSON v = TextDiff <$> (traverse itemFromJSON =<< parseJSON v)
@@ -187,7 +187,7 @@ instance Arbitrary ArgumentsDiff where
   arbitrary = ArgumentsDiff . NonEmpty.fromList <$> listOf1 arbitraryItem
 
 instance ToJSON ArgumentsDiff where
-  toJSON = listValue itemToJSON . toList . unArgumetsDiff
+  toJSON argumentsDiff = listValue itemToJSON (toList argumentsDiff.unArgumetsDiff)
 
 instance FromJSON ArgumentsDiff where
   parseJSON v = ArgumentsDiff <$> (traverse itemFromJSON =<< parseJSON v)

test/Golden/Utils.hs

@@ -44,7 +44,7 @@ makeDiffTree :: TestableDerivations -> DiffContext -> IO DerivationDiff
 makeDiffTree TestableDerivations{..} diffContext = do
   let status = Status Data.Set.empty
   let action = diff True oldDerivation (OutputNames (Data.Set.singleton "out")) newDerivation (OutputNames (Data.Set.singleton "out"))
-  Control.Monad.State.evalStateT (Control.Monad.Reader.runReaderT (unDiff action) diffContext) status
+  Control.Monad.State.evalStateT (Control.Monad.Reader.runReaderT action.unDiff diffContext) status
 
 -- | Drop conventional stdout newline, convert to StorePath
 storePathFromCLI :: BS.ByteString -> StorePath