[BUG] Installing dash breaks ability to run selenium / pylenium tests

[rnestler]

Describe your context Please provide us your environment, so we can easily reproduce the issue.

• replace the result of pip list | grep dash below

dash                 2.3.1
dash-core-components 2.0.0
dash-html-components 2.0.0
dash-table           5.0.0

Describe the bug

After installing dash pylenium can't start the webdriver anymore:

$ pytests
...
$ poetry add dash==2.3.1
...
$ pytests
...
E           urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='localhost', port=4444): Max retries exceeded with url: /wd/hub/session (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7fcd3eed0460>: Failed to establish a new connection: [Errno 111] Connection refused'))

The full output is quite overwhelming since it triggers several errors in a cascade while trying to setup and tear down the test fixtures.

localhost:4444 is where the webdriver server should respond.

Expected behavior

That tests still work.

Screenshots

Repository to reproduce the error: https://github.com/rnestler/minimal-pylenium-dash-example

Full output of the failure: output.txt

[rnestler]

I debugged it a bit further: I can install every dependency of dash except dash itself and the tests still work! So something in the dash package itself must be the issue.

[rnestler]

OK the culprit seems to be the dash/testing/plugin.py. When I just emty the file with echo > /home/raphael/.cache/pypoetry/virtualenvs/minimal-pylenium-dash-example-0I1Y-mga-py3.10/lib/python3.10/site-packages/dash/testing/plugin.py then the tests work again.

[rnestler]

Ah I can also disable it with pytest -p no:dash

[bmerry]

Is this maybe related to #1690?

[rnestler]

@bmerry Looks related to the test plugin as well, yes. I guess disabling it with pytest -p no:dash could work for you as well as a workaround.