What is the approved way of using meson test with meson-python?

[igo95862]

I already use meson test in my project to run python unittests. However, I do it a little bit backwards.

In the test folder every python test file has a if __name__ == "__main__" guard that runs the unittest.main() if the file is main script file. In meson I add a test for each file and run it with the python installation.

unittests = files(
    'test_helper.py',
    'test_profiles.py',
    'test_service_info.py',
    'test_auto_completion.py',
    'test_full_run.py',
)

foreach unittest : unittests
    test(
        fs.stem(unittest),
        py_installation,
        args : [unittest],
        env : test_env,
    )
endforeach

The magick that sets up the python code is the test_env environment.

test_env.set('PYTHONPATH', meson.current_build_dir())

The issue is I am not actually using install_sources to add the python files. Instead I use a custom_target with my own bytecode compiler. I was looking in to switching to install_sources but it seems to be impossible to replicate my current setup.
install_sources does not actually copy the python files to the build directory which makes it impossible to have a single PYTHONPATH to load the python package for the unit tests. Not sure how well using multiple paths in PYTHONPATH where one path is the source directory and the other one is build directory would work when there are both python files and extension modules.

[rgommers]

Hi @igo95862, thanks for your question. I'm not actually sure about my answer here, because there's multiple unusual things in your setup. A few thoughts:

• meson-python is only a build backend, meaning the only way to interact with it is through a build front-end like pip or build. At that point you get either an artifact (sdist and/or wheel) or an editable install. None of those are expected to work with meson test
• Use of PYTHONPATH manipulation is considered an anti-pattern; it's sometimes useful, but should in general not be a primary or only way to achieve your goal.
• For test files, there's usually a decision to make about whether or not to install them as part of your package. I'm not sure what you want there? If you do install them, can you run them with pytest --pyargs bubblejail?
• You don't have a pyproject.toml file in your repo, so you aren't using meson-python, right?
• Using meson test is unusual for a Python project, I'd expect it more for a mixed-language project with non-Python installable components. At that point, for development workflow you don't need meson-python. The two don't mix well.

[igo95862]

• meson-python is only a build backend, meaning the only way to interact with it is through a build front-end like pip or build. At that point you get either an artifact (sdist and/or wheel) or an editable install. None of those are expected to work with meson test

Maybe it is more of the question to the meson project itself and its python module.

The --editable pip mode might be a replacement since it recompiles the extensions on source change. The unit tests then could be run in a venv ./venv/bin/python -m unittest.

Not sure how to integrate the meson's run_target though.