1 files changed, 50 insertions, 0 deletions
diff --git a/Lib/test/test_class.py b/Lib/test/test_class.py
index b88c4d1..7720cf1 100644
--- a/Lib/test/test_class.py
+++ b/Lib/test/test_class.py
@@ -503,6 +503,56 @@ class ClassTests(unittest.TestCase):
 
         self.assertRaises(TypeError, hash, C2())
 
+    def testPredefinedAttrs(self):
+        o = object()
+
+        class Custom:
+            pass
+
+        c = Custom()
+
+        methods = (
+            '__class__', '__delattr__', '__dir__', '__eq__', '__format__',
+            '__ge__', '__getattribute__', '__getstate__', '__gt__', '__hash__',
+            '__init__', '__init_subclass__', '__le__', '__lt__', '__ne__',
+            '__new__', '__reduce__', '__reduce_ex__', '__repr__',
+            '__setattr__', '__sizeof__', '__str__', '__subclasshook__'
+        )
+        for name in methods:
+            with self.subTest(name):
+                self.assertTrue(callable(getattr(object, name, None)))
+                self.assertTrue(callable(getattr(o, name, None)))
+                self.assertTrue(callable(getattr(Custom, name, None)))
+                self.assertTrue(callable(getattr(c, name, None)))
+
+        not_defined = [
+            '__abs__', '__aenter__', '__aexit__', '__aiter__', '__anext__',
+            '__await__', '__bool__', '__bytes__', '__ceil__',
+            '__complex__', '__contains__', '__del__', '__delete__',
+            '__delitem__', '__divmod__', '__enter__', '__exit__',
+            '__float__', '__floor__', '__get__', '__getattr__', '__getitem__',
+            '__index__', '__int__', '__invert__', '__iter__', '__len__',
+            '__length_hint__', '__missing__', '__neg__', '__next__',
+            '__objclass__', '__pos__', '__rdivmod__', '__reversed__',
+            '__round__', '__set__', '__setitem__', '__trunc__'
+        ]
+        augment = (
+            'add', 'and', 'floordiv', 'lshift', 'matmul', 'mod', 'mul', 'pow',
+            'rshift', 'sub', 'truediv', 'xor'
+        )
+        not_defined.extend(map("__{}__".format, augment))
+        not_defined.extend(map("__r{}__".format, augment))
+        not_defined.extend(map("__i{}__".format, augment))
+        for name in not_defined:
+            with self.subTest(name):
+                self.assertFalse(hasattr(object, name))
+                self.assertFalse(hasattr(o, name))
+                self.assertFalse(hasattr(Custom, name))
+                self.assertFalse(hasattr(c, name))
+
+        # __call__() is defined on the metaclass but not the class
+        self.assertFalse(hasattr(o, "__call__"))
+        self.assertFalse(hasattr(c, "__call__"))
 
     def testSFBug532646(self):
         # Test for SF bug 532646