fix field schema directives applied to roots

codegen/field.go

@@ -288,6 +288,9 @@ func (f *Field) HasDirectives() bool {
 }
 
 func (f *Field) DirectiveObjName() string {
+	if f.Object.Root {
+		return "nil"
+	}
 	return f.GoReceiverName
 }
 

codegen/testserver/directive.graphql

@@ -0,0 +1,25 @@
+directive @length(min: Int!, max: Int, message: String) on ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION | FIELD_DEFINITION
+directive @range(min: Int = 0, max: Int) on ARGUMENT_DEFINITION
+directive @custom on ARGUMENT_DEFINITION
+directive @logged(id: UUID!) on FIELD
+
+extend type Query {
+    directiveArg(arg: String! @length(min:1, max: 255, message: "invalid length")): String
+    directiveNullableArg(arg: Int @range(min:0), arg2: Int @range): String
+    directiveInputNullable(arg: InputDirectives): String
+    directiveInput(arg: InputDirectives!): String
+    directiveInputType(arg: InnerInput! @custom): String
+    directiveFieldDef(ret: String!): String! @length(min: 1, message: "not valid")
+    directiveField: String
+}
+
+input InputDirectives {
+    text: String! @length(min: 0, max: 7, message: "not valid")
+    inner: InnerDirectives!
+    innerNullable: InnerDirectives
+    thirdParty: ThirdParty @length(min: 0, max: 7)
+}
+
+input InnerDirectives {
+    message: String! @length(min: 1, message: "not valid")
+}

codegen/testserver/directive_test.go

@@ -180,6 +180,31 @@ func TestDirectives(t *testing.T) {
 			require.Equal(t, "Ok", *resp.DirectiveArg)
 		})
 	})
+	t.Run("field definition directives", func(t *testing.T) {
+		resolvers.QueryResolver.DirectiveFieldDef = func(ctx context.Context, ret string) (i string, e error) {
+			return ret, nil
+		}
+
+		t.Run("too short", func(t *testing.T) {
+			var resp struct {
+				DirectiveFieldDef string
+			}
+
+			err := c.Post(`query { directiveFieldDef(ret: "") }`, &resp)
+
+			require.EqualError(t, err, `[{"message":"not valid","path":["directiveFieldDef"]}]`)
+		})
+
+		t.Run("ok", func(t *testing.T) {
+			var resp struct {
+				DirectiveFieldDef string
+			}
+
+			c.MustPost(`query { directiveFieldDef(ret: "aaa") }`, &resp)
+
+			require.Equal(t, "aaa", resp.DirectiveFieldDef)
+		})
+	})
 	t.Run("field directives", func(t *testing.T) {
 		t.Run("add field directive", func(t *testing.T) {
 			var resp struct {