Restrict the usage of TypeProxy instances

graphene/types/tests/test_argument.py

@@ -28,7 +28,7 @@ def test_argument_type():
 
 
 def test_argument_graphene_type():
-    argument = Argument(String())
+    argument = Argument(String)
     assert argument.type == GraphQLString
 
 
@@ -44,7 +44,7 @@ def test_copy_argument_works():
 
 
 def test_to_arguments():
-    arguments = to_arguments(a=String(), b=Argument(GraphQLString), c=Argument(String()))
+    arguments = to_arguments(a=String(), b=Argument(GraphQLString), c=Argument(String))
     assert list(arguments.keys()) == ['a', 'b', 'c']
     assert [a.type for a in arguments.values()] == [GraphQLString] * 3
 

graphene/types/tests/test_structures.py

@@ -7,38 +7,38 @@ from ..scalars import String
 
 
 def test_list():
-    list_instance = List(String())
+    list_instance = List(String)
     assert isinstance(list_instance, GraphQLList)
     assert list_instance.of_type == GraphQLString
 
 
 def test_list_lambda():
-    list_instance = List(lambda: String())
+    list_instance = List(lambda: String)
     assert isinstance(list_instance, GraphQLList)
     assert list_instance.of_type == GraphQLString
 
 
 def test_list_list():
-    list_instance = List(List(String()))
+    list_instance = List(List(String))
     assert isinstance(list_instance, GraphQLList)
     assert isinstance(list_instance.of_type, GraphQLList)
     assert list_instance.of_type.of_type == GraphQLString
 
 
 def test_nonnull():
-    list_instance = NonNull(String())
+    list_instance = NonNull(String)
     assert isinstance(list_instance, GraphQLNonNull)
     assert list_instance.of_type == GraphQLString
 
 
 def test_nonnull_lambda():
-    list_instance = NonNull(lambda: String())
+    list_instance = NonNull(lambda: String)
     assert isinstance(list_instance, GraphQLNonNull)
     assert list_instance.of_type == GraphQLString
 
 
 def test_nonnull_list():
-    list_instance = NonNull(List(String()))
+    list_instance = NonNull(List(String))
     assert isinstance(list_instance, GraphQLNonNull)
     assert isinstance(list_instance.of_type, GraphQLList)
     assert list_instance.of_type.of_type == GraphQLString

graphene/utils/is_graphene_type.py

@@ -7,12 +7,10 @@ from ..types.enum import Enum
 
 
 def is_graphene_type(_type):
-    if inspect.isclass(_type):
-        return issubclass(_type, (
-            Interface,
-            ObjectType,
-            InputObjectType,
-            Scalar,
-            Enum
-        ))
-    return is_graphene_type(type(_type))
+    return inspect.isclass(_type) and issubclass(_type, (
+        Interface,
+        ObjectType,
+        InputObjectType,
+        Scalar,
+        Enum
+    ))