Conda tests session should skip rather than fail if conda not installed

[FollowTheProcess]

Describe the bug

While quickly doing #519, I noticed that running bare nox on my machine results in somewhat unattractive looking failures:

I think a better solution would be to first check if the user has conda and skip this session if not (much like the tests themselves have a pytest.mark.skipif condition.

How to reproduce

Run nox on this project without having conda installed.

Expected behavior

Should skip conda_tests if conda is not installed.

This is a super quick fix and I'll do it now, filing the issue for traceability 🙂

[DiddiLeija]

I can reproduce this using Windows. I think skipping conda_tests could be useful. Actually, we can add something to nox.session to add a conditional to skip sessions?

[FollowTheProcess]

@DiddiLeija Yeah potentially, something like

if <something that would render the session useless>:
    session.skip(reason="Missing something needed for the session")

Kind of like pytest's mark.skipif.

I think this could be a bit complex to implement though and might be better served with the simple nox.options.sessions filter?

[DiddiLeija]

something like

if <something that would render the session useless>:
    session.skip(reason="Missing something needed for the session")

Kind of like pytest's mark.skipif.

Yup. I'm looking for something like that.

I think this could be a bit complex to implement though and might be better served with the simple nox.options.sessions filter?

I will take a closer look for this idea later, probably next year.

[FollowTheProcess]

@DiddiLeija I've just found out session.skip is already a thing!