automated_test_scripts\tests>pytest -v -s --firefox-preference="browser.helperApps.neverAsk.openFile"="application/excel" test_login.py"
i got error:
usage: pytest [options] [file_or_dir] [file_or_dir] [...]
pytest: error: argument --firefox-preference: expected 2 argument(s).
I tried different combination and all the time i got the same error.
I using a synthax in command line from >pytest -h

Here is link for temporary resolve of this problem: pytest-dev/pytest-selenium#86 (comment)

Thanks for your time