diff --git a/Lib/unittest/async_case.py b/Lib/unittest/async_case.py index 520213c3727555..86ed7046c499a3 100644 --- a/Lib/unittest/async_case.py +++ b/Lib/unittest/async_case.py @@ -135,7 +135,7 @@ def _tearDownAsyncioLoop(self): 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 d01864b6936ca8..6e48b9e4bfed36 100644 --- a/Lib/unittest/test/test_async_case.py +++ b/Lib/unittest/test/test_async_case.py @@ -216,6 +216,26 @@ async def test_cancel(self): 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 00000000000000..f8aed69a40a3be --- /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