bpo-44515: handle non-refcounted GC in contextlib tests (GH-26910) (GH-27379)

Co-authored-by: Łukasz Langa <lukasz@langa.pl>
(cherry picked from commit a2c45e5)

Co-authored-by: Nick Coghlan <ncoghlan@gmail.com>

Author: miss-islington

Lib/test/test_contextlib.py

@@ -231,6 +231,8 @@ class A:
         def woohoo(a, b):
             a = weakref.ref(a)
             b = weakref.ref(b)
+            # Allow test to work with a non-refcounted GC
+            support.gc_collect()
             self.assertIsNone(a())
             self.assertIsNone(b())
             yield

Lib/test/test_contextlib_async.py

@@ -1,7 +1,7 @@
 import asyncio
 from contextlib import (
     asynccontextmanager, AbstractAsyncContextManager,
-    AsyncExitStack, nullcontext, aclosing)
+    AsyncExitStack, nullcontext, aclosing, contextmanager)
 import functools
 from test import support
 import unittest
@@ -357,14 +357,17 @@ async def aclose(self):
     async def test_aclosing_bpo41229(self):
         state = []
 
-        class Resource:
-            def __del__(self):
+        @contextmanager
+        def sync_resource():
+            try:
+                yield
+            finally:
                 state.append(1)
 
         async def agenfunc():
-            r = Resource()
-            yield -1
-            yield -2
+            with sync_resource():
+                yield -1
+                yield -2
 
         x = agenfunc()
         self.assertEqual(state, [])

Misc/NEWS.d/next/Tests/2021-06-26-18-37-36.bpo-44515.e9fO6f.rst

@@ -0,0 +1,2 @@
+Adjust recently added contextlib tests to avoid assuming the use of a
+refcounted GC