gh-121084: Fix test_typing random leaks (GH-121360)

Clear typing ABC caches when running tests for refleaks (-R option): call _abc_caches_clear() on typing abstract classes and their subclasses. (cherry picked from commit 5f660e8) Co-authored-by: Victor Stinner <vstinner@python.org>
python · vstinner · Jul 4, 2024 · Jul 4, 2024 · Jul 4, 2024 · 066e6487bc258f1c4b37d31dae923b9ba55b27f5
commit 066e6487bc258f1c4b37d31dae923b9ba55b27f5
diff --git a/Lib/test/libregrtest/utils.py b/Lib/test/libregrtest/utils.py
@@ -264,6 +264,12 @@ def clear_caches():
         for f in typing._cleanups:
             f()
 
+        import inspect
+        abs_classes = filter(inspect.isabstract, typing.__dict__.values())
+        for abc in abs_classes:
+            for obj in abc.__subclasses__() + [abc]:
+                obj._abc_caches_clear()
+
     try:
         fractions = sys.modules['fractions']
     except KeyError:

diff --git a/Misc/NEWS.d/next/Tests/2024-07-04-15-10-29.gh-issue-121084.qxcd5d.rst b/Misc/NEWS.d/next/Tests/2024-07-04-15-10-29.gh-issue-121084.qxcd5d.rst
@@ -0,0 +1,3 @@
+Fix test_typing random leaks. Clear typing ABC caches when running tests for
+refleaks (``-R`` option): call ``_abc_caches_clear()`` on typing abstract
+classes and their subclasses. Patch by Victor Stinner.