async def test_awaitables_are_cancelled_and_cleaned_up_on_outer_cancellation():
token = CancelToken('token')
ready = asyncio.Event()
got_cancelation = asyncio.Event()
async def _signal_then_sleep():
ready.set()
try:
await asyncio.sleep(10)
except asyncio.CancelledError:
got_cancelation.set()
raise
fut = asyncio.ensure_future(_signal_then_sleep())
task = asyncio.ensure_future(token.cancellable_wait(fut))
# wait till we know the coro is running
await ready.wait()
# cancel the task
task.cancel()
try:
await task
except asyncio.CancelledError:
pass
# ensure that the task was indeed cancelled.
await asyncio.wait_for(got_cancelation.wait(), timeout=0.01)
await assert_only_current_task_not_done()
async def test_cancellable_wait_cancels_subtasks_when_cancelled(event_loop):
token = CancelToken('')
future = asyncio.ensure_future(token.cancellable_wait(asyncio.sleep(2)))
with pytest.raises(asyncio.TimeoutError):
# asyncio.wait_for() will timeout and then cancel our cancellable_wait() future, but
# Task.cancel() doesn't immediately cancels the task
# (https://docs.python.org/3/library/asyncio-task.html#asyncio.Task.cancel), so we need
# the sleep below before we check that the task is actually cancelled.
await asyncio.wait_for(future, timeout=0.01)
await asyncio.sleep(0)
assert future.cancelled()
await assert_only_current_task_not_done()
async def test_finished_task_with_exceptions_is_raised_on_cancellation():
token = CancelToken('token')
ready = asyncio.Event()
async def _signal_then_raise():
ready.set()
raise ValueError("raising from _signal_then_raise")
# schedule in the background
task = asyncio.ensure_future(token.cancellable_wait(_signal_then_raise()))
# wait until the coro is running and we know it's raised an error
await ready.wait()
# trigger the cancel token
token.trigger()
with pytest.raises(ValueError, match="raising from _signal_then_raise"):
await task
await assert_only_current_task_not_done()