Improved fields inheritance in ObjectTypes

graphene/core/fields.py

@@ -17,6 +17,10 @@ from graphene.core.types import BaseObjectType
 from graphene.core.scalars import GraphQLSkipField
 
 
+class Empty(object):
+    pass
+
+
 @total_ordering
 class Field(object):
     SKIP = GraphQLSkipField
@@ -142,6 +146,14 @@ class Field(object):
     def __hash__(self):
         return hash(self.creation_counter)
 
+    def __copy__(self):
+        # We need to avoid hitting __reduce__, so define this
+        # slightly weird copy construct.
+        obj = Empty()
+        obj.__class__ = self.__class__
+        obj.__dict__ = self.__dict__.copy()
+        return obj
+
 
 class NativeField(Field):
 

graphene/core/options.py

@@ -64,10 +64,7 @@ class Options(object):
 
     @cached_property
     def fields(self):
-        fields = []
-        for parent in self.parents:
-            fields.extend(parent._meta.fields)
-        return sorted(self.local_fields + fields)
+        return sorted(self.local_fields)
 
     @cached_property
     def fields_map(self):

graphene/core/types.py

@@ -1,5 +1,6 @@
 import inspect
 import six
+import copy
 from collections import OrderedDict
 
 from graphql.core.type import (
@@ -72,13 +73,20 @@ class ObjectTypeMeta(type):
             # on the base classes (we cannot handle shadowed fields at the
             # moment).
             for field in parent_fields:
-                if field.name in field_names and field.__class__ != field_names[field].__class__:
+                if field.name in field_names and field.__class__ != field_names[field.name].__class__:
                     raise Exception(
                         'Local field %r in class %r clashes '
-                        'with field of similar name from '
-                        'base class %r' % (
-                            field.name, name, base.__name__)
+                        'with field with similar name from '
+                        'Interface %s (%r != %r)' % (
+                            field.name,
+                            new_class.__name__,
+                            base.__name__,
+                            field.__class__,
+                            field_names[field.name].__class__)
                     )
+                new_field = copy.copy(field)
+                new_class.add_to_class(field.field_name, new_field)
+
             new_class._meta.parents.append(base)
             if base._meta.interface:
                 new_class._meta.interfaces.append(base)

tests/core/test_types.py

@@ -3,6 +3,7 @@ from collections import namedtuple
 from pytest import raises
 from graphene.core.fields import (
     Field,
+    IntField,
     StringField,
 )
 from graphql.core.type import (
@@ -60,3 +61,10 @@ def test_object_type():
     assert object_type.get_fields() == {'name': Character._meta.fields_map['name'].internal_field(
         schema), 'friends': Human._meta.fields_map['friends'].internal_field(schema)}
     assert object_type.get_interfaces() == [Character.internal_type(schema)]
+
+
+def test_field_clashes():
+    with raises(Exception) as excinfo:
+        class Droid(Character):
+            name = IntField()
+    assert 'clashes' in str(excinfo.value)