asyncio errors on Python 3.11 (and older)

[mdmintz]

asyncio errors on Python 3.11 (and older)

Caused by a regression in4.37.10 for an edge case.

This isn't happening on Python 3.12 (or newer).

Python 3.12 made improvements to asyncio:

There's a recent SeleniumBase asyncio memory-saving feature that works great on Python 3.12 (and newer), but it causes some asyncio errors on 3.11 and older because those versions of Python have an asyncio issue that wasn't fixed until Python 3.12.

This reproduces the issue on Python 3.11:

from seleniumbase import SB

with SB(uc=True, test=True) as sb:
    sb.activate_cdp_mode()
    sb.open("data:text/html,<h1>Page A</h1>")
    sb.assert_text("Page A")
    sb.open_new_tab()
    sb.open("data:text/html,<h1>Page B</h1>")
    sb.assert_text("Page B")
    sb.switch_to_tab(0)
    sb.assert_text("Page A")
    sb.assert_text_not_visible("Page B")
    sb.switch_to_tab(1)
    sb.assert_text("Page B")
    sb.assert_text_not_visible("Page A")

ERROR:asyncio:Task was destroyed but it is pending!
task: <Task cancelling name='Task-3' coro=<Listener.listener_loop() running at ~/SeleniumBase/seleniumbase/undetected/cdp_driver/connection.py:575> wait_for=<Future pending cb=[Task.task_wakeup()]>>

[mdmintz]

This was resolved in 4.37.11 - https://github.com/seleniumbase/SeleniumBase/releases/tag/v4.37.11

[felipehertzer]

Hey @mdmintz,

I tested this on Python 3.11 and was able to reproduce the bug. I resolved the issue by modifying the Listener.cancel method. With this change, the leak no longer occurs in Python 3.11. The root cause was that Listener.cancel was not awaiting the cancellation process, but only on 3.11 (That is weird).

async def cancel(self):
    if self.task and not self.task.cancelled():
        self.task.cancel()
        try:
            await self.task
        except asyncio.CancelledError:
            pass

and then add the awaits:

await self.listener.cancel()

[mdmintz]

@felipehertzer Thanks for investigating that. I'll ship a new release shortly with the fix.