bpo-46469: Make asyncio generic classes return GenericAlias (GH-30777)

* bpo-46469: Make asyncio generic classes return GenericAlias

* 📜🤖 Added by blurb_it.

* Update Misc/NEWS.d/next/Library/2022-01-22-05-05-08.bpo-46469.plUab5.rst

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Lib/test/test_asyncio/test_futures.py

@@ -7,7 +7,7 @@ import sys
 import threading
 import unittest
 from unittest import mock
-
+from types import GenericAlias
 import asyncio
 from asyncio import futures
 from test.test_asyncio import utils as test_utils
@@ -109,6 +109,11 @@ class BaseFutureTests:
         self.loop = self.new_test_loop()
         self.addCleanup(self.loop.close)
 
+    def test_generic_alias(self):
+        future = self.cls[str]
+        self.assertEqual(future.__args__, (str,))
+        self.assertIsInstance(future, GenericAlias)
+
     def test_isfuture(self):
         class MyFuture:
             _asyncio_future_blocking = None

Lib/test/test_asyncio/test_queues.py

@@ -1,9 +1,8 @@
 """Tests for queues.py"""
 
 import unittest
-from unittest import mock
-
 import asyncio
+from types import GenericAlias
 from test.test_asyncio import utils as test_utils
 
 
@@ -74,6 +73,11 @@ class QueueBasicTests(_QueueTestBase):
     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):
         q = asyncio.Queue()
         self.assertTrue(q.empty())

Lib/test/test_asyncio/test_tasks.py

@@ -11,10 +11,10 @@ import re
 import sys
 import textwrap
 import traceback
-import types
 import unittest
 import weakref
 from unittest import mock
+from types import GenericAlias
 
 import asyncio
 from asyncio import coroutines
@@ -108,6 +108,12 @@ class BaseTaskTests:
         self.loop.set_task_factory(self.new_task)
         self.loop.create_future = lambda: self.new_future(self.loop)
 
+
+    def test_generic_alias(self):
+        task = self.__class__.Task[str]
+        self.assertEqual(task.__args__, (str,))
+        self.assertIsInstance(task, GenericAlias)
+
     def test_task_cancel_message_getter(self):
         async def coro():
             pass