bpo-44911: Fixed IsolatedAsyncioTestCase from throwing an exception on leaked tasks (GH-27765)
diff --git a/Lib/unittest/async_case.py b/Lib/unittest/async_case.py
index 520213c..86ed704 100644
--- a/Lib/unittest/async_case.py
+++ b/Lib/unittest/async_case.py
@@ -135,7 +135,7 @@
task.cancel()
loop.run_until_complete(
- asyncio.gather(*to_cancel, loop=loop, return_exceptions=True))
+ asyncio.gather(*to_cancel, return_exceptions=True))
for task in to_cancel:
if task.cancelled():
diff --git a/Lib/unittest/test/test_async_case.py b/Lib/unittest/test/test_async_case.py
index d01864b..6e48b9e 100644
--- a/Lib/unittest/test/test_async_case.py
+++ b/Lib/unittest/test/test_async_case.py
@@ -216,6 +216,26 @@
output = test.run()
self.assertFalse(output.wasSuccessful())
+ def test_cancellation_hanging_tasks(self):
+ cancelled = False
+ class Test(unittest.IsolatedAsyncioTestCase):
+ async def test_leaking_task(self):
+ async def coro():
+ nonlocal cancelled
+ try:
+ await asyncio.sleep(1)
+ except asyncio.CancelledError:
+ cancelled = True
+ raise
+
+ # Leave this running in the background
+ asyncio.create_task(coro())
+
+ test = Test("test_leaking_task")
+ output = test.run()
+ self.assertTrue(cancelled)
+
+
if __name__ == "__main__":
diff --git a/Misc/NEWS.d/next/Library/2021-08-14-00-55-16.bpo-44911.uk3hYk.rst b/Misc/NEWS.d/next/Library/2021-08-14-00-55-16.bpo-44911.uk3hYk.rst
new file mode 100644
index 0000000..f8aed69
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-08-14-00-55-16.bpo-44911.uk3hYk.rst
@@ -0,0 +1 @@
+:class:`~unittest.IsolatedAsyncioTestCase` will no longer throw an exception while cancelling leaked tasks. Patch by Bar Harel.
\ No newline at end of file
