[v0.3.2] Add support for discovering fields from bases.

Closes #5

Author: jhgg

epoxy/metaclasses/input_type.py

@@ -16,7 +16,7 @@ def __new__(mcs, name, bases, attrs):
 
         name = attrs.pop('_name', name)
         class_ref = WeakRefHolder()
-        declared_fields = get_declared_fields(name, yank_potential_fields(attrs, InputField), InputField)
+        declared_fields = get_declared_fields(name, yank_potential_fields(attrs, bases, InputField), InputField)
         interface = GraphQLInputObjectType(
             name,
             fields=partial(mcs._build_field_map, class_ref, declared_fields),

epoxy/metaclasses/interface.py

@@ -13,7 +13,7 @@ def __new__(mcs, name, bases, attrs):
             return super(InterfaceMeta, mcs).__new__(mcs, name, bases, attrs)
 
         class_ref = WeakRefHolder()
-        declared_fields = get_declared_fields(name, yank_potential_fields(attrs))
+        declared_fields = get_declared_fields(name, yank_potential_fields(attrs, bases))
         interface = GraphQLInterfaceType(
             name,
             fields=partial(mcs._build_field_map, class_ref, declared_fields),

epoxy/metaclasses/object_type.py

@@ -16,7 +16,8 @@ def __new__(mcs, name, bases, attrs):
         name = attrs.pop('_name', name)
         class_ref = WeakRefHolder()
         registry = mcs._get_registry()
-        declared_fields = get_declared_fields(name, yank_potential_fields(attrs))
+
+        declared_fields = get_declared_fields(name, yank_potential_fields(attrs, bases))
 
         with no_implementation_registration():
             object_type = GraphQLObjectType(

epoxy/utils/yank_potential_fields.py

@@ -2,10 +2,18 @@
 from .thunk import TypeThunk
 
 
-def yank_potential_fields(attrs, field_class=Field):
+def yank_potential_fields(attrs, bases, field_class=Field):
     field_attrs = {}
     potential_types = (field_class, TypeThunk)
 
+    for klass in reversed(bases):
+        for field_attr_name, obj in klass.__dict__.items():
+            if field_attr_name == 'T':
+                continue
+
+            if isinstance(obj, potential_types):
+                field_attrs[field_attr_name] = obj
+
     for field_attr_name, obj in list(attrs.items()):
         if field_attr_name == 'T':
             continue

tests/test_declarative_definition.py

@@ -13,7 +13,6 @@ def check_dog(R, Dog):
     assert fields['name'].type == GraphQLString
     assert fields['name'].name == 'name'
 
-
 def test_register_single_type():
     R = TypeRegistry()
 
@@ -50,6 +49,18 @@ class Dog(R.ObjectType):
     check_dog(R, Dog)
 
 
+def test_can_use_mixins():
+    R = TypeRegistry()
+
+    class DogMixin():
+        name = R.String
+
+    class Dog(R.ObjectType, DogMixin):
+        pass
+
+    check_dog(R, Dog)
+
+
 def test_register_type_can_declare_builtin_scalar_type_as_non_null():
     R = TypeRegistry()