From 3ee94131ae511d2d83116730dcc4a50258ced5af Mon Sep 17 00:00:00 2001
From: Syrus Akbary <me@syrusakbary.com>
Date: Thu, 2 Nov 2017 21:57:10 -0700
Subject: [PATCH] Improved object container initialization. Fixed #585

---
 graphene/types/objecttype.py            |  2 +-
 graphene/types/tests/test_mutation.py   | 28 +++++++++++++++++++++++++
 graphene/types/tests/test_objecttype.py | 28 +++++++++++++++++++++++++
 3 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/graphene/types/objecttype.py b/graphene/types/objecttype.py
index fe234b09..a16d2b60 100644
--- a/graphene/types/objecttype.py
+++ b/graphene/types/objecttype.py
@@ -81,7 +81,7 @@ class ObjectType(BaseType):
 
         for name, field in fields_iter:
             try:
-                val = kwargs.pop(name)
+                val = kwargs.pop(name, None)
                 setattr(self, name, val)
             except KeyError:
                 pass
diff --git a/graphene/types/tests/test_mutation.py b/graphene/types/tests/test_mutation.py
index 69e14b0c..91ab14d2 100644
--- a/graphene/types/tests/test_mutation.py
+++ b/graphene/types/tests/test_mutation.py
@@ -105,3 +105,31 @@ def test_mutation_execution():
             'dynamic': 'dynamic',
         }
     }
+
+
+def test_mutation_no_fields_output():
+    class CreateUser(Mutation):
+        name = String()
+
+        def mutate(self, info):
+            return CreateUser()
+
+    class Query(ObjectType):
+        a = String()
+
+    class MyMutation(ObjectType):
+        create_user = CreateUser.Field()
+
+    schema = Schema(query=Query, mutation=MyMutation)
+    result = schema.execute(''' mutation mymutation {
+        createUser {
+            name
+        }
+    }
+    ''')
+    assert not result.errors
+    assert result.data == {
+        'createUser': {
+            'name': None,
+        }
+    }
diff --git a/graphene/types/tests/test_objecttype.py b/graphene/types/tests/test_objecttype.py
index 9ad0f817..e7c76d97 100644
--- a/graphene/types/tests/test_objecttype.py
+++ b/graphene/types/tests/test_objecttype.py
@@ -5,6 +5,8 @@ from ..interface import Interface
 from ..objecttype import ObjectType
 from ..unmountedtype import UnmountedType
 from ..structures import NonNull
+from ..scalars import String
+from ..schema import Schema
 
 
 class MyType(Interface):
@@ -224,3 +226,29 @@ def test_objecttype_with_possible_types_and_is_type_of_should_raise():
         'MyObjectType.Meta.possible_types will cause type collision with '
         'MyObjectType.is_type_of. Please use one or other.'
     )
+
+
+def test_objecttype_no_fields_output():
+    class User(ObjectType):
+        name = String()
+
+    class Query(ObjectType):
+        user = Field(User)
+
+        def resolve_user(self, info):
+            return User()
+
+
+    schema = Schema(query=Query)
+    result = schema.execute(''' query basequery {
+        user {
+            name
+        }
+    }
+    ''')
+    assert not result.errors
+    assert result.data == {
+        'user': {
+            'name': None,
+        }
+    }