From a7f174c54b1d8e9b41d58f412c103629664fa644 Mon Sep 17 00:00:00 2001
From: Dmitry Kropachev <dmitry.kropachev@gmail.com>
Date: Sun, 1 Feb 2026 07:17:12 -0400
Subject: [PATCH 1/2] Replace asynctest with stdlib mock

The asynctest package is unmaintained since 2020 and incompatible with
Python 3.12+. Replace asynctest.TestSelector with a MagicMock using
selectors.BaseSelector as its spec, which provides the same mock
selector functionality needed by the asyncio reactor tests.

Fixes #663
---
 pyproject.toml                       | 1 -
 tests/unit/io/test_asyncioreactor.py | 7 +++----
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 1c195e1b77..e524051042 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,7 +52,6 @@ dev = [
     "cython>=3.2",
     "packaging>=25.0",
     "futurist",
-    "asynctest",
     "pyyaml",
     "numpy",
     "objgraph",
diff --git a/tests/unit/io/test_asyncioreactor.py b/tests/unit/io/test_asyncioreactor.py
index c189aa3d74..f3ed942090 100644
--- a/tests/unit/io/test_asyncioreactor.py
+++ b/tests/unit/io/test_asyncioreactor.py
@@ -1,7 +1,6 @@
 AsyncioConnection, ASYNCIO_AVAILABLE = None, False
 try:
     from cassandra.io.asyncioreactor import AsyncioConnection
-    import asynctest
     ASYNCIO_AVAILABLE = True
 except (ImportError, SyntaxError, AttributeError):
     AsyncioConnection = None
@@ -10,8 +9,8 @@
 from tests import is_monkey_patched, connection_class
 from tests.unit.io.utils import TimerCallback, TimerTestMixin
 
-from unittest.mock import patch
-
+from unittest.mock import patch, MagicMock
+import selectors
 import unittest
 import time
 
@@ -56,7 +55,7 @@ def setUp(self):
         socket_patcher.start()
 
         old_selector = AsyncioConnection._loop._selector
-        AsyncioConnection._loop._selector = asynctest.TestSelector()
+        AsyncioConnection._loop._selector = MagicMock(spec=selectors.BaseSelector)
 
         def reset_selector():
             AsyncioConnection._loop._selector = old_selector

From caf2f7ad1edcb145f9b43fe4d85a9e716ec2ff38 Mon Sep 17 00:00:00 2001
From: Dmitry Kropachev <dmitry.kropachev@gmail.com>
Date: Sun, 1 Feb 2026 13:24:04 -0400
Subject: [PATCH 2/2] Fix flaky test_multi_timer_validation on Windows CI

Increase timer tolerance from 150ms to 500ms to account for CI
environments under heavy load, especially Windows during wheel
building where timing can be significantly less precise.
---
 tests/unit/io/utils.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tests/unit/io/utils.py b/tests/unit/io/utils.py
index 174137225a..f43224058c 100644
--- a/tests/unit/io/utils.py
+++ b/tests/unit/io/utils.py
@@ -128,8 +128,10 @@ def submit_and_wait_for_completion(unit_test, create_timer, start, end, incremen
         time.sleep(.1)
 
     # ensure they are all called back in a timely fashion
+    # Use a generous tolerance (500ms) to account for CI environments under heavy load,
+    # especially Windows during wheel building where timing can be significantly less precise
     for callback in completed_callbacks:
-        assert callback.expected_wait == pytest.approx(callback.get_wait_time(), abs=.15)
+        assert callback.expected_wait == pytest.approx(callback.get_wait_time(), abs=.5)
 
 
 def noop_if_monkey_patched(f):