ci: add multiple test targets

[eigenmannmartin]

closes ##147

[DerDreschner]

That doesn't work. icalendar 6.0 had a breaking change when using the internal WINDOWS_TO_OLSON map (change of namespace) and use_pytz() needs to be used for the old behaviour as they changed the default timezone database. The latter may be not needed - I didn't tested icalevents with the new default to be honest. But I didn't want to take any risk here. See #145. It must be >=5.0.3,<6.0 here if you revert the changes from #145, but then it will not work for people who need the newest icalendar release.

I'm not that confident with Python, but I guess it's not possible to wrap the code lines in any if clause, depending on the used dependency version?

[DerDreschner]

Okay, after doing some research, it may be possible. This Stack Overflow answer - together with the discussion here - would result in something like

from importlib.metadata import version

if version("icalendar") >= "6.0":
    from icalendar import use_pytz
    from icalendar.timezone.windows_to_olson import WINDOWS_TO_OLSON

    use_pytz()
else:
    from icalendar.windows_to_olson import WINDOWS_TO_OLSON

as solution. But the question is how we would test everything with both versions in the pipelines? 🤔 I can only think about two new steps using hard-coded installation actions for icalendar?

[andrewgy8]

Yep, this would be the proper work around @DerDreschner .

But the question is how we would test everything with both versions in the pipelines?

Typically you use a testing matrix which allows different versions of dependencies and python versions, like the above workflow. However, you can also add into the matrix the versions of icalendar that you would like to see tested. In this case, <6.0 and >6.0. Here is an example that uses Django in that regard and should be straightforward to add in this PR.

[DerDreschner]

I would be interested to learn what the problem with ~= is in this case. 😄

[DerDreschner]

I've opened a separate pull request for adding icalendar 5.0 support (#160). For housekeeping reasons, I would prefer to revert the icalendar version change and focus on the test matrix for different Python versions.

[eigenmannmartin]

I've opened a separate pull request for adding icalendar 5.0 support (#160). For housekeeping reasons, I would prefer to revert the icalendar version change and focus on the test matrix for different Python versions.

agree!