Fix duplicated ErrorType declaration (#539)

* Add failing test case

* Fix duplicated ErrorType declaration

graphene_django/forms/mutation.py

@@ -14,7 +14,7 @@ from graphene.types.utils import yank_fields_from_attrs
 from graphene_django.registry import get_global_registry
 
 from .converter import convert_form_field
-from .types import ErrorType
+from ..types import ErrorType
 
 
 def fields_for_form(form, only_fields, exclude_fields):

graphene_django/rest_framework/mutation.py

@@ -9,7 +9,7 @@ from graphene.relay.mutation import ClientIDMutation
 from graphene.types.objecttype import yank_fields_from_attrs
 
 from .serializer_converter import convert_serializer_field
-from .types import ErrorType
+from ..types import ErrorType
 
 
 class SerializerMutationOptions(MutationOptions):

graphene_django/rest_framework/types.py

@@ -2,11 +2,6 @@ import graphene
 from graphene.types.unmountedtype import UnmountedType
 
 
-class ErrorType(graphene.ObjectType):
-    field = graphene.String(required=True)
-    messages = graphene.List(graphene.NonNull(graphene.String), required=True)
-
-
 class DictType(UnmountedType):
     key = graphene.String()
     value = graphene.String()

graphene_django/tests/issues/test_520.py

@@ -0,0 +1,44 @@
+# https://github.com/graphql-python/graphene-django/issues/520
+
+import datetime
+
+from django import forms
+
+import graphene
+
+from graphene import Field, ResolveInfo
+from graphene.types.inputobjecttype import InputObjectType
+from py.test import raises
+from py.test import mark
+from rest_framework import serializers
+
+from ...types import DjangoObjectType
+from ...rest_framework.models import MyFakeModel
+from ...rest_framework.mutation import SerializerMutation
+from ...forms.mutation import DjangoFormMutation
+
+
+class MyModelSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = MyFakeModel
+        fields = "__all__"
+
+
+class MyForm(forms.Form):
+    text = forms.CharField()
+
+
+def test_can_use_form_and_serializer_mutations():
+    class MyMutation(SerializerMutation):
+        class Meta:
+            serializer_class = MyModelSerializer
+
+    class MyFormMutation(DjangoFormMutation):
+        class Meta:
+            form_class = MyForm
+
+    class Mutation(graphene.ObjectType):
+        my_mutation = MyMutation.Field()
+        my_form_mutation = MyFormMutation.Field()
+
+    graphene.Schema(mutation=Mutation)

graphene_django/types.py

@@ -3,6 +3,7 @@ from collections import OrderedDict
 
 from django.db.models import Model
 from django.utils.functional import SimpleLazyObject
+import graphene
 from graphene import Field
 from graphene.relay import Connection, Node
 from graphene.types.objecttype import ObjectType, ObjectTypeOptions
@@ -144,3 +145,8 @@ class DjangoObjectType(ObjectType):
             return queryset.get(pk=id)
         except cls._meta.model.DoesNotExist:
             return None
+
+
+class ErrorType(ObjectType):
+    field = graphene.String(required=True)
+    messages = graphene.List(graphene.NonNull(graphene.String), required=True)