[Question]: Task was destroyed but it is pending! in route.abort()

[cyberfuhrer]

Your question

Why am I getting an error in route.abort()?
Example:

from playwright.sync_api import sync_playwright

def handle_route(route):
    if route.request.resource_type == "image":
        response = page.request.fetch(route.request)
	if int(response.headers['content-length']) > 500:
	    route.abort()
	else:
	    route.continue_()
    else:
        route.continue_()

playwright = sync_playwright().start()
browser = playwright.chromium.launch()
context = browser.new_context()
context.route('**/*', handle_route)
page = context.new_page()
page.goto(url='https://www.pinterest.com/', timeout=10000)
page.wait_for_timeout(3000)
page.close()
context.close()
browser.close()

Task was destroyed but it is pending!
task: <Task pending coro=<BrowserContext._on_route() running at /usr/local/lib/python3.7/dist-packages/playwright/_impl/_browser_context.py:187> wait_for=<_GatheringFuture pending cb=[<TaskWakeupMethWrapper object at 0x7f2c168870d8>()]>>
...

Playwright version 1.23.0

[rwoll]

Thanks for the report—your code looks good and this is likely a leak introduced by the new requests handling code. It will be addressed, but it should be safe to ignore the warning for now.

[x0day]

Thanks for the report—your code looks good and this is likely a leak introduced by the new requests handling code. It will be addressed, but it should be safe to ignore the warning for now.

@rwoll

after this commit 7b424eb, _on_route calling method has changed, where channel closed before _on_route called not taken into account, and this warning is appeared.

1.23.0

playwright-python/playwright/_impl/_page.py

Lines 193 to 200 in 36ff52e

	self._channel.on(
	"route",
	lambda params: asyncio.create_task(
	self._on_route(
	from_channel(params["route"]), from_channel(params["request"])
	)
	),
	)

1.22.0

playwright-python/playwright/_impl/_page.py

Lines 195 to 200 in 97c6490

	self._channel.on(
	"route",
	lambda params: self._on_route(
	from_channel(params["route"]), from_channel(params["request"])
	),
	)

and with this issue and same reason, we also meet this error after upgrade to 1.23.0.

task: <Task pending name='Task-82983' coro=<Page._on_route() running at /opt/venv/lib/python3.8/site-packages/playwright/_impl/_page.py:246> wait_for=<_GatheringFuture pending cb=[<TaskWakeupMethWrapper object at 0x7f1c36070250>()]> cb=[AsyncIOEventEmitter._emit_run.<locals>._callback() at /opt/venv/lib/python3.8/site-packages/pyee/_asyncio.py:55]>
[E 220706 03:05:34 PID:10] [asyncio] Task exception was never retrieved
future: <Task finished name='Task-80531' coro=<Page._disable_interception() done, defined at /opt/venv/lib/python3.8/site-packages/playwright/_impl/_page.py:623> exception=Error('Playwright connection closed')>
Traceback (most recent call last):
  File "/opt/venv/lib/python3.8/site-packages/playwright/_impl/_page.py", line 624, in _disable_interception
    await self._channel.send("setNetworkInterceptionEnabled", dict(enabled=False))
  File "/opt/venv/lib/python3.8/site-packages/playwright/_impl/_connection.py", line 43, in send
    return await self._connection.wrap_api_call(
  File "/opt/venv/lib/python3.8/site-packages/playwright/_impl/_connection.py", line 370, in _
    return await result
  File "/opt/venv/lib/python3.8/site-packages/playwright/_impl/_connection.py", line 64, in inner_send
    callback = self._connection._send_message_to_server(self._guid, method, params)
  File "/opt/venv/lib/python3.8/site-packages/playwright/_impl/_connection.py", line 265, in _send_message_to_server
    self._transport.send(message)
  File "/opt/venv/lib/python3.8/site-packages/playwright/_impl/_transport.py", line 250, in send
    raise Error("Playwright connection closed")
playwright._impl._api_types.Error: Playwright connection closed

[rwoll]

Re-opening. The fix we landed might be non-exhaustive, and I'm not longer convinced it's the correct fix.

[ja8zyjits]

@rwoll shouldn't we add a self._background_task_tracker.close() in the page._on_close() method too?

[rwoll]

@rwoll shouldn't we add a self._background_task_tracker.close() in the page._on_close() method too?

I don't think that's exhaustive. There's a bunch of places where we call create_task and don't await, so it looks like the proper fix is to loop over the pending tasks when we go to exit the Python PW context manager cancelling. I'm currently finishing off some other work, but I will be looping back to this shortly. (To my knowledge, the current release has a leak and annoying log line sometimes, but is not functionally broken/blocking folks. If this is incorrect, please let me know.)

Thanks for your patience!