bpo-45755: [typing] Reveal class attributes of generic in generic aliases in `dir()` (GH-29962)

(cherry picked from commit d6e13747161d7b634b47d2d3d212ed3be4a21fab)

Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index fdec29ea58..82b6f8c1c6 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -4994,6 +4994,17 @@ class SpecialAttrsTests(BaseTestCase):
             loaded = pickle.loads(s)
             self.assertIs(SpecialAttrsP, loaded)
 
+    def test_genericalias_dir(self):
+        class Foo(Generic[T]):
+            def bar(self):
+                pass
+            baz = 3
+        # The class attributes of the original class should be visible even
+        # in dir() of the GenericAlias. See bpo-45755.
+        self.assertIn('bar', dir(Foo[int]))
+        self.assertIn('baz', dir(Foo[int]))
+
+
 class AllTests(BaseTestCase):
     """Tests for __all__."""