Testing a Flask app with pytest-flask + pytest-selenium (docker)

Regarding the problem with a direct call with urllib:

Pytest's live server uses random port by default. You can add this parameter to pytest invocation:

--live-server-port 5000

Or without this parameter you can make direct calls to live server like:

import pytestimport requestsfrom flask import url_for@pytest.mark.usefixtures('live_server')def test_something():    r = requests.get(url_for('index', _external=True))    assert r.status_code == 200

I suppose you have view function called index. It would add a correct port number automatically.

But this doesn't have to do anything with docker, how do you run it?

Regarding the problem with Selenium itself - I can imagine docker networks related problem. How do you use it? Do you have eg. docker-compose configuration? Can you share it?

The referenced pytest-selenium issue has:

@pytest.fixturedef firefox_options(firefox_options, pytestconfig):    if pytestconfig.getoption('headless'):        firefox_options.add_argument('-headless')    return firefox_options

Note the - (single dash) preceding headless in add_argument()

(Source)

For late comers, it might be worthwhile taking a look at Xvfb and even more helpful can be this tutorial

Then (in Linux shell) you can enter:

Xvfb :99 &export DISPLAY=:99pytest --driver Firefox --driver-path /usr/local/bin/firefox test_app.py

This provides a virtual frame buffer (fake screen) for the application and it outputs all the graphical content there.

Note that I did not encountered this problem, just providing a solution that helped me overcome the mentioned error with an another app.