[3.9] bpo-46469: Make asyncio generic classes return GenericAlias (GH-30777) (GH-30785)

Automerge-Triggered-By: GH:asvetlov

Lib/test/test_asyncio/test_queues.py

@@ -4,6 +4,7 @@
 from unittest import mock
 
 import asyncio
+from types import GenericAlias
 from test.test_asyncio import utils as test_utils
 
 
@@ -92,6 +93,11 @@ def test_repr(self):
     def test_str(self):
         self._test_repr_or_str(str, False)
 
+    def test_generic_alias(self):
+        q = asyncio.Queue[int]
+        self.assertEqual(q.__args__, (int,))
+        self.assertIsInstance(q, GenericAlias)
+
     def test_empty(self):
         with self.assertWarns(DeprecationWarning):
             q = asyncio.Queue(loop=self.loop)