Extract collectFields function

CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on
 and this project adheres to
 [Haskell Package Versioning Policy](https://pvp.haskell.org/).
 
+## [Unreleased]
+
 ## [0.11.0.0] - 2020-11-07
 ### Changed
 - `AST.Document.Selection` wraps additional new types: `Field`, `FragmentSpread`
@@ -400,6 +402,7 @@ and this project adheres to
 ### Added
 - Data types for the GraphQL language.
 
+[Unreleased]: https://www.caraus.tech/projects/pub-graphql/repository/23/diff?rev=master&rev_to=v0.11.0.0
 [0.11.0.0]: https://www.caraus.tech/projects/pub-graphql/repository/23/diff?rev=v0.11.0.0&rev_to=v0.10.0.0
 [0.10.0.0]: https://www.caraus.tech/projects/pub-graphql/repository/23/diff?rev=v0.10.0.0&rev_to=v0.9.0.0
 [0.9.0.0]: https://www.caraus.tech/projects/pub-graphql/repository/23/diff?rev=v0.9.0.0&rev_to=v0.8.0.0

src/Language/GraphQL/Validate/Rules.hs

@@ -123,8 +123,8 @@ executableDefinitionsRule = DefinitionRule $ \case
 singleFieldSubscriptionsRule :: forall m. Rule m
 singleFieldSubscriptionsRule = OperationDefinitionRule $ \case
     Full.OperationDefinition Full.Subscription name' _ _ rootFields location' -> do
-        groupedFieldSet <- evalStateT (collectFields rootFields) HashSet.empty
-        case HashSet.size groupedFieldSet of
+        groupedFieldSet <- collectFields rootFields
+        case length groupedFieldSet of
             1 -> lift mempty
             _
                 | Just name <- name' -> pure $ Error
@@ -143,18 +143,26 @@ singleFieldSubscriptionsRule = OperationDefinitionRule $ \case
   where
     errorMessage =
         "Anonymous Subscription must select only one top level field."
-    collectFields selectionSet = foldM forEach HashSet.empty selectionSet
+
+collectFields :: forall m
+    . NonEmpty Full.Selection
+    -> ReaderT (Validation m) Seq [[Full.Field]]
+collectFields selectionSet = evalStateT go HashSet.empty
+  where
+    go = groupSorted getFieldName <$> accumulateFields [] selectionSet
+    getFieldName (Full.Field alias name _ _ _ _)
+        | Just aliasedName <- alias = aliasedName
+        | otherwise = name
+    accumulateFields = foldM forEach
     forEach accumulator = \case
         Full.FieldSelection fieldSelection -> forField accumulator fieldSelection
         Full.FragmentSpreadSelection fragmentSelection ->
             forSpread accumulator fragmentSelection
         Full.InlineFragmentSelection fragmentSelection ->
             forInline accumulator fragmentSelection
-    forField accumulator (Full.Field alias name _ directives' _ _)
+    forField accumulator field@(Full.Field _ _ _ directives' _ _)
         | any skip directives' = pure accumulator
-        | Just aliasedName <- alias = pure
-            $ HashSet.insert aliasedName accumulator
-        | otherwise = pure $ HashSet.insert name accumulator
+        | otherwise = pure $ field : accumulator
     forSpread accumulator (Full.FragmentSpread fragmentName directives' _)
         | any skip directives' = pure accumulator
         | otherwise = do
@@ -166,14 +174,8 @@ singleFieldSubscriptionsRule = OperationDefinitionRule $ \case
         | any skip directives' = pure accumulator
         | Just typeCondition <- maybeType =
             collectFromFragment typeCondition selections accumulator
-        | otherwise = HashSet.union accumulator
-            <$> collectFields selections
-    skip (Full.Directive "skip" [Full.Argument "if" (Full.Node argumentValue _) _] _) =
-        Full.Boolean True == argumentValue
-    skip (Full.Directive "include" [Full.Argument "if" (Full.Node argumentValue _) _] _) =
-        Full.Boolean False == argumentValue
-    skip _ = False
-    collectFromFragment typeCondition selectionSet accumulator = do
+        | otherwise = accumulateFields accumulator selections
+    collectFromFragment typeCondition selectionSet' accumulator = do
         types' <- lift $ asks $ Schema.types . schema
         schema' <- lift $ asks schema
         case Type.lookupTypeCondition typeCondition types' of
@@ -181,15 +183,20 @@ singleFieldSubscriptionsRule = OperationDefinitionRule $ \case
             Just compositeType
                 | Just objectType <- Schema.subscription schema'
                 , True <- Type.doesFragmentTypeApply compositeType objectType ->
-                    HashSet.union accumulator <$> collectFields selectionSet
+                    accumulateFields accumulator selectionSet'
                 | otherwise -> pure accumulator
     collectFromSpread fragmentName accumulator = do
         modify $ HashSet.insert fragmentName
         ast' <- lift $ asks ast
         case findFragmentDefinition fragmentName ast' of
             Nothing -> pure accumulator
-            Just (Full.FragmentDefinition _ typeCondition _ selectionSet _) ->
-                collectFromFragment typeCondition selectionSet accumulator
+            Just (Full.FragmentDefinition _ typeCondition _ selectionSet' _) ->
+                collectFromFragment typeCondition selectionSet' accumulator
+    skip (Full.Directive "skip" [Full.Argument "if" (Full.Node argumentValue _) _] _) =
+        Full.Boolean True == argumentValue
+    skip (Full.Directive "include" [Full.Argument "if" (Full.Node argumentValue _) _] _) =
+        Full.Boolean False == argumentValue
+    skip _ = False
 
 -- | GraphQL allows a short‐hand form for defining query operations when only
 -- that one operation exists in the document.
@@ -451,8 +458,7 @@ filterSelections applyFilter selections
 noFragmentCyclesRule :: forall m. Rule m
 noFragmentCyclesRule = FragmentDefinitionRule $ \case
     Full.FragmentDefinition fragmentName _ _ selections location' -> do
-        state <- evalStateT (collectFields selections)
-            (0, fragmentName)
+        state <- evalStateT (collectCycles selections) (0, fragmentName)
         let spreadPath = fst <$> sortBy (comparing snd) (HashMap.toList state)
         case reverse spreadPath of
             x : _ | x == fragmentName -> pure $ Error
@@ -467,10 +473,10 @@ noFragmentCyclesRule = FragmentDefinitionRule $ \case
                 }
             _ -> lift mempty
   where
-    collectFields :: Traversable t
+    collectCycles :: Traversable t
         => t Full.Selection
         -> StateT (Int, Full.Name) (ReaderT (Validation m) Seq) (HashMap Full.Name Int)
-    collectFields selectionSet = foldM forEach HashMap.empty selectionSet
+    collectCycles selectionSet = foldM forEach HashMap.empty selectionSet
     forEach accumulator = \case
         Full.FieldSelection fieldSelection -> forField accumulator fieldSelection
         Full.InlineFragmentSelection fragmentSelection ->
@@ -487,15 +493,15 @@ noFragmentCyclesRule = FragmentDefinitionRule $ \case
             then pure newAccumulator
             else collectFromSpread fragmentName newAccumulator
     forInline accumulator (Full.InlineFragment _ _ selections _) =
-        (accumulator <>) <$> collectFields selections
+        (accumulator <>) <$> collectCycles selections
     forField accumulator (Full.Field _ _ _ _ selections _) =
-        (accumulator <>) <$> collectFields selections
+        (accumulator <>) <$> collectCycles selections
     collectFromSpread fragmentName accumulator = do
         ast' <- lift $ asks ast
         case findFragmentDefinition fragmentName ast' of
             Nothing -> pure accumulator
             Just (Full.FragmentDefinition _ _ _ selections _) ->
-                (accumulator <>) <$> collectFields selections
+                (accumulator <>) <$> collectCycles selections
 
 findFragmentDefinition :: Text
     -> NonEmpty Full.Definition
@@ -531,15 +537,22 @@ uniqueDirectiveNamesRule = DirectivesRule
     extract (Full.Directive directiveName _ location') =
         (directiveName, location')
 
-filterDuplicates :: (a -> (Text, Full.Location)) -> String -> [a] -> Seq Error
+groupSorted :: forall a. (a -> Text) -> [a] -> [[a]]
+groupSorted getName = groupBy equalByName . sortOn getName
+  where
+    equalByName lhs rhs = getName lhs == getName rhs
+
+filterDuplicates :: forall a
+    . (a -> (Text, Full.Location))
+    -> String
+    -> [a]
+    -> Seq Error
 filterDuplicates extract nodeType = Seq.fromList
     . fmap makeError
     . filter ((> 1) . length)
-    . groupBy equalByName
-    . sortOn getName
+    . groupSorted getName
   where
     getName = fst . extract
-    equalByName lhs rhs = getName lhs == getName rhs
     makeError directives' = Error
         { message = makeMessage $ head directives'
         , locations = snd . extract <$> directives'

stack.yaml

@@ -1,4 +1,4 @@
-resolver: lts-16.20
+resolver: lts-16.21
 
 packages:
 - .