diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py index 211dd89ea4851c..c71c56877f690f 100644 --- a/Lib/test/test_builtin.py +++ b/Lib/test/test_builtin.py @@ -2091,6 +2091,24 @@ def test_warning_notimplemented(self): with self.assertWarns(DeprecationWarning): self.assertFalse(not NotImplemented) + def test_singleton_attribute_access(self): + for singleton in (NotImplemented, Ellipsis): + with self.subTest(singleton): + self.assertIs(type(singleton), singleton.__class__) + self.assertIs(type(singleton).__class__, type) + + # Missing instance attributes: + with self.assertRaises(AttributeError): + singleton.prop = 1 + with self.assertRaises(AttributeError): + singleton.prop + + # Missing class attributes: + with self.assertRaises(TypeError): + type(singleton).prop = 1 + with self.assertRaises(AttributeError): + type(singleton).prop + class TestBreakpoint(unittest.TestCase): def setUp(self):