Add unit tests and continuous integration

[xylar]

These tests require some small changes to the checker and the generator so it can run in a temp directory.

They test the different expected failure modes of the checker (as well as successes).

They should run automatically with pushes and pull requests.

[xylar]

Unfortunately, I don't think CI will run until after this goes in.

[xylar]

$ conda activate isschecker
(isschecker) xylar@katara:~/code/ISM_SimulationChecker/add-ci-and-unit-tests$ pytest tests
============================= test session starts ==============================
platform linux -- Python 3.14.4, pytest-9.0.3, pluggy-1.6.0
rootdir: /home/xylar/code/ISM_SimulationChecker/add-ci-and-unit-tests
collected 6 items                                                              

tests/test_compliance_checker.py ......                                  [100%]

============================== 6 passed in 1.04s ===============================

Works locally for me at least.

[hgoelzer]

Hi, this looks like a good addition. I hopefully can look at it in more detail soon. But here already one top-level comment.
It may be that 'tests' is the default location for this, but having both 'test' and 'tests' seems a bit confusing on first look. Any chance we can resolve that. If 'tests' is indeed the standard, we may rename 'test' to 'generate' or similar.

[xylar]

Good call, @hgoelzer. I was struggling with test and tests. The latter is, indeed, a standard name but I was going to rename it unit_tests. But I like your idea of renaming test to generate better so I've done that.

[xylar]

Tests aren't running here in the pull request yet but they are running on my fork:
https://github.com/xylar/ISM_SimulationChecker/actions/runs/25373388060/job/74402245575

[hgoelzer]

Looks good and works for me. After running pytest I was wondering where the test netcdf files were and realised they are created on the fly and deleted again, in line with an automated test procedure. I've learned that the files can be retained and inspected by adding --basetemp to the call, like so
conda run -n isschecker pytest -v tests/test_compliance_checker.py --basetemp=/tmp/pytest_tmp
This could be added to the README for transparency, unless this is just my curiosity and not relevant for our standard use case. I leave that judgement up to you. Great to have this feature in. Thanks

[xylar]

@hgoelzer, --basetemp isn't a feature I've used before but it looks like it could be useful. I added it to the README.