Added Union type

graphene/generators/definitions.py

@@ -1,6 +1,6 @@
 from graphql import (GraphQLEnumType, GraphQLInputObjectType,
                      GraphQLInterfaceType, GraphQLObjectType,
-                     GraphQLScalarType)
+                     GraphQLScalarType, GraphQLUnionType)
 
 
 class GrapheneGraphQLType(object):
@@ -18,6 +18,10 @@ class GrapheneInterfaceType(GrapheneGraphQLType, GraphQLInterfaceType):
     pass
 
 
+class GrapheneUnionType(GrapheneGraphQLType, GraphQLUnionType):
+    pass
+
+
 class GrapheneObjectType(GrapheneGraphQLType, GraphQLObjectType):
     pass
 

graphene/new_types/interface.py

@@ -28,12 +28,15 @@ class InterfaceMeta(AbstractTypeMeta):
 
         return type.__new__(cls, name, bases, dict(attrs, _meta=options))
 
+    def __str__(cls):
+        return cls._meta.name
+
 
 class Interface(six.with_metaclass(InterfaceMeta)):
     resolve_type = None
 
     def __init__(self, *args, **kwargs):
-        raise Exception("An interface cannot be intitialized")
+        raise Exception("An Interface cannot be intitialized")
 
     # @classmethod
     # def implements(cls, objecttype):

graphene/new_types/objecttype.py

@@ -28,6 +28,9 @@ class ObjectTypeMeta(AbstractTypeMeta):
 
         return type.__new__(cls, name, bases, dict(attrs, _meta=options))
 
+    def __str__(cls):
+        return cls._meta.name
+
 
 class ObjectType(six.with_metaclass(ObjectTypeMeta)):
 

graphene/new_types/scalars.py

@@ -25,6 +25,9 @@ class ScalarTypeMeta(type):
 
         return super_new(cls, name, bases, dict(attrs, _meta=options))
 
+    def __str__(cls):
+        return cls._meta.name
+
 
 class Scalar(six.with_metaclass(ScalarTypeMeta, UnmountedType)):
     serialize = None

graphene/new_types/tests/test_definition.py

@@ -3,6 +3,8 @@ from collections import OrderedDict
 from py.test import raises
 
 from ..objecttype import ObjectType
+from ..interface import Interface
+from ..union import Union
 from ..scalars import String, Int, Boolean
 from ..field import Field
 from ..structures import List
@@ -44,6 +46,15 @@ class Subscription(ObjectType):
     article_subscribe = Field(Article)  # id=String()
 
 
+class MyInterface(Interface):
+    pass
+
+
+class MyUnion(Union):
+    class Meta:
+        types = (Article, )
+
+
 def test_defines_a_query_only_schema():
     blog_schema = Schema(Query)
 
@@ -177,11 +188,11 @@ def test_defines_a_subscription_schema():
 #     assert schema.get_type_map()['SomeSubtype'] == SomeSubtype
 
 
-# def test_stringifies_simple_types():
-#     assert str(GraphQLInt) == 'Int'
-#     assert str(BlogArticle) == 'Article'
-#     assert str(InterfaceType) == 'Interface'
-#     assert str(UnionType) == 'Union'
+def test_stringifies_simple_types():
+    assert str(Int) == 'Int'
+    assert str(Article) == 'Article'
+    assert str(MyInterface) == 'MyInterface'
+    assert str(MyUnion) == 'MyUnion'
     # assert str(EnumType) == 'Enum'
     # assert str(InputObjectType) == 'InputObject'
     # assert str(GraphQLNonNull(GraphQLInt)) == 'Int!'

graphene/new_types/tests/test_union.py

@@ -0,0 +1,42 @@
+import pytest
+
+from ..objecttype import ObjectType
+from ..union import Union
+
+
+class MyObjectType1(ObjectType):
+    pass
+
+
+class MyObjectType2(ObjectType):
+    pass
+
+
+def test_generate_union():
+    class MyUnion(Union):
+        '''Documentation'''
+        class Meta:
+            types = (MyObjectType1, MyObjectType2)
+
+    assert MyUnion._meta.name == "MyUnion"
+    assert MyUnion._meta.description == "Documentation"
+    assert MyUnion._meta.types == (MyObjectType1, MyObjectType2)
+
+
+def test_generate_union_with_meta():
+    class MyUnion(Union):
+        class Meta:
+            name = 'MyOtherUnion'
+            description = 'Documentation'
+            types = (MyObjectType1, MyObjectType2)
+
+    assert MyUnion._meta.name == "MyOtherUnion"
+    assert MyUnion._meta.description == "Documentation"
+
+
+def test_generate_union_with_no_types():
+    with pytest.raises(Exception) as exc_info:
+        class MyUnion(Union):
+            pass
+
+    assert str(exc_info.value) == 'Must provide types for Union MyUnion.'

graphene/new_types/union.py

@@ -0,0 +1,37 @@
+import six
+
+from ..utils.is_base_type import is_base_type
+from .options import Options
+
+
+class UnionMeta(type):
+
+    def __new__(cls, name, bases, attrs):
+        # Also ensure initialization is only performed for subclasses of
+        # Union
+        if not is_base_type(bases, UnionMeta):
+            return type.__new__(cls, name, bases, attrs)
+
+        options = Options(
+            attrs.pop('Meta', None),
+            name=name,
+            description=attrs.get('__doc__'),
+            types=(),
+        )
+
+        assert (
+            isinstance(options.types, (list, tuple)) and
+            len(options.types) > 0
+        ), 'Must provide types for Union {}.'.format(options.name)
+
+        return type.__new__(cls, name, bases, dict(attrs, _meta=options))
+
+    def __str__(cls):
+        return cls._meta.name
+
+
+class Union(six.with_metaclass(UnionMeta)):
+    resolve_type = None
+
+    def __init__(self, *args, **kwargs):
+        raise Exception("An Union cannot be intitialized")