Define __prepare__() in with_metaclass()

CONTRIBUTORS

@@ -27,5 +27,6 @@ Peter Ruibal
 Miroslav Shubernetskiy
 Anthony Sottile
 Lucas Wiman
+Jordan Moldow
 
 If you think you belong on this list, please let me know! --Benjamin

six.py

@@ -824,6 +824,10 @@ class metaclass(meta):
 
         def __new__(cls, name, this_bases, d):
             return meta(name, bases, d)
+
+        @classmethod
+        def __prepare__(cls, name, this_bases):
+            return meta.__prepare__(name, bases)
     return type.__new__(metaclass, 'temporary_class', (), {})
 
 

test_six.py

@@ -743,6 +743,34 @@ class X(six.with_metaclass(Meta, Base, Base2)):
     assert X.__mro__ == (X, Base, Base2, object)
 
 
+@py.test.mark.skipif("sys.version_info[:2] < (3, 0)")
+def test_with_metaclass_prepare():
+    """Test that with_metaclass causes Meta.__prepare__ to be called with the correct arguments."""
+
+    class MyDict(dict):
+        pass
+
+    class Meta(type):
+
+        @classmethod
+        def __prepare__(cls, name, bases):
+            namespace = MyDict(super().__prepare__(name, bases), cls=cls, bases=bases)
+            namespace['namespace'] = namespace
+            return namespace
+
+    class Base(object):
+        pass
+
+    bases = (Base,)
+
+    class X(six.with_metaclass(Meta, *bases)):
+        pass
+
+    assert getattr(X, 'cls', type) is Meta
+    assert getattr(X, 'bases', ()) == bases
+    assert isinstance(getattr(X, 'namespace', {}), MyDict)
+
+
 def test_wraps():
     def f(g):
         @six.wraps(g)