Parse interfaces implementing interfaces

src/Language/GraphQL/AST/Document.hs

@@ -482,12 +482,9 @@ instance Monoid Description
 data TypeDefinition
     = ScalarTypeDefinition Description Name [Directive]
     | ObjectTypeDefinition
-        Description
+        Description Name (ImplementsInterfaces []) [Directive] [FieldDefinition]
-        Name
+    | InterfaceTypeDefinition
-        (ImplementsInterfaces [])
+        Description Name (ImplementsInterfaces []) [Directive] [FieldDefinition]
-        [Directive]
-        [FieldDefinition]
-    | InterfaceTypeDefinition Description Name [Directive] [FieldDefinition]
     | UnionTypeDefinition Description Name [Directive] (UnionMemberTypes [])
     | EnumTypeDefinition Description Name [Directive] [EnumValueDefinition]
     | InputObjectTypeDefinition

src/Language/GraphQL/AST/Encoder.hs

@@ -226,10 +226,11 @@ typeDefinition formatter = \case
         <> optempty (directives formatter) directives'
         <> eitherFormat formatter " " ""
         <> bracesList formatter (fieldDefinition nextFormatter) fields'
-    Full.InterfaceTypeDefinition description' name' directives' fields'
+    Full.InterfaceTypeDefinition description' name' ifaces' directives' fields'
         -> optempty (description formatter) description'
         <> "interface "
         <> Lazy.Text.fromStrict name'
+        <> optempty (" " <>) (implementsInterfaces ifaces')
         <> optempty (directives formatter) directives'
         <> eitherFormat formatter " " ""
         <> bracesList formatter (fieldDefinition nextFormatter) fields'

src/Language/GraphQL/AST/Parser.hs

@@ -214,6 +214,7 @@ interfaceTypeDefinition :: Full.Description -> Parser Full.TypeDefinition
 interfaceTypeDefinition description' = Full.InterfaceTypeDefinition description'
     <$ symbol "interface"
     <*> name
+    <*> option (Full.ImplementsInterfaces []) (implementsInterfaces sepBy1)
     <*> directives
     <*> braces (many fieldDefinition)
     <?> "InterfaceTypeDefinition"

src/Language/GraphQL/Validate.hs

@@ -210,7 +210,7 @@ typeDefinition context rule = \case
     Full.ObjectTypeDefinition _ _ _ directives' fields
         -> directives context rule objectLocation directives'
         >< foldMap (fieldDefinition context rule) fields
-    Full.InterfaceTypeDefinition _ _ directives' fields
+    Full.InterfaceTypeDefinition _ _ _ directives' fields
         -> directives context rule interfaceLocation directives'
         >< foldMap (fieldDefinition context rule) fields
     Full.UnionTypeDefinition _ _ directives' _ ->

tests/Language/GraphQL/AST/EncoderSpec.hs

@@ -181,7 +181,7 @@ spec = do
                 argument = Full.InputValueDefinition mempty "arg" someType Nothing mempty
                 arguments = Full.ArgumentsDefinition [argument]
                 definition' = Full.TypeDefinition
-                    $ Full.InterfaceTypeDefinition mempty "UUID" mempty
+                    $ Full.InterfaceTypeDefinition mempty "UUID" (Full.ImplementsInterfaces []) mempty
                     $ pure
                     $ Full.FieldDefinition mempty "value" arguments someType mempty
                 expected = "interface UUID {\n\

tests/Language/GraphQL/AST/ParserSpec.hs

@@ -103,6 +103,12 @@ spec = describe "Parser" $ do
             \  name: String\n\
             \}"
 
+    it "parses ImplementsInterfaces on interfaces" $
+        parse document "" `shouldSucceedOn`
+            "interface Person implements NamedEntity & ValuedEntity {\n\
+            \  name: String\n\
+            \}"
+
     it "parses minimal enum type definition" $
         parse document "" `shouldSucceedOn`
             "enum Direction {\n\