Deprecate enum, enumA, wrappedEnum, wrappedEnumA

These functions are from Language.GraphQL.Schema.
There are actually only two generic types in GraphQL: Scalars and objects.
Enum is a scalar value. According to the specification enums may be
serailized to strings. And in the current implementation they used
untyped strings anyway, so there is no point to have differently named
functions with the same implementation as their scalar counterparts.

CHANGELOG.md

@@ -12,6 +12,9 @@ All notable changes to this project will be documented in this file.
   the user separately, because the schema can originate from a GraphQL
   document. `Schema` name should be free to provide a data type for the real
   schema later.
+- `Language.GraphQL.Schema`: `enum`, `enumA`, `wrappedEnum` and `wrappedEnumA`.
+  There are actually only two generic types in GraphQL: Scalars and objects.
+  Enum is a scalar value.
 
 ## [0.5.0.0] - 2019-08-14
 ### Added

src/Language/GraphQL/Schema.hs

@@ -111,18 +111,17 @@ wrappedScalar :: (MonadIO m, Aeson.ToJSON a)
     => Name -> ActionT m (Wrapping a) -> Resolver m
 wrappedScalar name = wrappedScalarA name . const
 
--- | Represents one of a finite set of possible values.
+{-# DEPRECATED enum "Use scalar instead" #-}
---   Used in place of a 'scalar' when the possible responses are easily enumerable.
 enum :: MonadIO m => Name -> ActionT m [Text] -> Resolver m
 enum name = enumA name . const
 
--- | Like 'enum' but also taking 'Argument's.
+{-# DEPRECATED enumA "Use scalarA instead" #-}
 enumA :: MonadIO m => Name -> (Arguments -> ActionT m [Text]) -> Resolver m
 enumA name f = Resolver name $ resolveFieldValue f resolveRight
   where
     resolveRight fld resolver = withField (return resolver) fld
 
--- | Like 'enum' but also taking 'Argument's and can be null or a list of enums.
+{-# DEPRECATED wrappedEnumA "Use wrappedScalarA instead" #-}
 wrappedEnumA :: MonadIO m
     => Name -> (Arguments -> ActionT m (Wrapping [Text])) -> Resolver m
 wrappedEnumA name f = Resolver name $ resolveFieldValue f resolveRight
@@ -132,7 +131,7 @@ wrappedEnumA name f = Resolver name $ resolveFieldValue f resolveRight
         = return $ HashMap.singleton (aliasOrName fld) Aeson.Null
     resolveRight fld (List resolver) = withField (return resolver) fld
 
--- | Like 'enum' but can be null or a list of enums.
+{-# DEPRECATED wrappedEnum "Use wrappedScalar instead" #-}
 wrappedEnum :: MonadIO m => Name -> ActionT m (Wrapping [Text]) -> Resolver m
 wrappedEnum name = wrappedEnumA name . const
 

stack.yaml

@@ -1,4 +1,4 @@
-resolver: lts-14.3
+resolver: lts-14.4
 packages:
 - '.'
 extra-deps: []

tests/Test/StarWars/Data.hs

@@ -26,6 +26,7 @@ import Control.Monad.Trans.Except (throwE)
 import Data.Maybe (catMaybes)
 import Data.Text (Text)
 import Language.GraphQL.Trans
+import Language.GraphQL.Type
 
 -- * Data
 -- See https://github.com/graphql/graphql-js/blob/master/src/__tests__/starWarsData.js
@@ -190,8 +191,8 @@ getDroid' _      = empty
 getFriends :: Character -> [Character]
 getFriends char = catMaybes $ liftA2 (<|>) getDroid getHuman <$> friends char
 
-getEpisode :: Alternative f => Int -> f Text
+getEpisode :: Int -> Maybe (Wrapping Text)
-getEpisode 4 = pure "NEWHOPE"
+getEpisode 4 = pure $ Named "NEWHOPE"
-getEpisode 5 = pure "EMPIRE"
+getEpisode 5 = pure $ Named "EMPIRE"
-getEpisode 6 = pure "JEDI"
+getEpisode 6 = pure $ Named "JEDI"
 getEpisode _ = empty

tests/Test/StarWars/Schema.hs

@@ -12,6 +12,7 @@ import Control.Monad.Trans.Except (throwE)
 import Control.Monad.Trans.Class (lift)
 import Control.Monad.IO.Class (MonadIO(..))
 import Data.List.NonEmpty (NonEmpty(..))
+import Data.Maybe (catMaybes)
 import qualified Language.GraphQL.Schema as Schema
 import Language.GraphQL.Trans
 import Language.GraphQL.Type
@@ -50,7 +51,8 @@ character char = return
     , Schema.scalar "name" $ return $ name char
     , Schema.wrappedObject "friends"
         $ traverse character $ List $ Named <$> getFriends char
-    , Schema.enum "appearsIn" $ return $ foldMap getEpisode $ appearsIn char
+    , Schema.wrappedScalar "appearsIn" $ return . List
+        $ catMaybes (getEpisode <$> appearsIn char)
     , Schema.scalar "secretBackstory" $ secretBackstory char
     , Schema.scalar "homePlanet" $ return $ either mempty homePlanet char
     , Schema.scalar "__typename" $ return $ typeName char