Mark test as 'run-always'

[MartinBernstorff]

Is your feature request related to a problem? Please describe.
I have a few tests which depend on .cfg files on disk. Since testmon doesn't support checking those .cfg files, a super simple solution is to run the test all the time.

Describe the solution you'd like
Run all tests with a specific pytest or testmon decorator.

Describe alternatives you've considered
None so far.

[psobot]

+1, this would be quite useful as a decorator; something like@always_run or @never_skip:

@testmon.always_run
def test_my_thing():
    with open("my_file.cfg") as f:
        assert ...

[kpodl-inoqo]

I have a similar use case: testmon does not detect changes to alembic DB migrations which are tested through pytest-alembic.

For this it would be very convenient to have a command line option that selects tests affected by changes OR selected by pytest selectors (in contrast to --testmon-forceselect that selects tests affected by changes AND selected by pytest selectors).

This would be a generalization of @MartinBernstorff's pytest marker: You could choose what tests to always run by using standard pytest selectors.

Example:

pytest --testmon-unionselect -m alembic

(This would run all tests selected by testmon and those with the alembic marker).