python unittest discover in SikuliX

Question

I know that in normal python, to discover python scripts for test

cd python_project
python -m unittest discover

I also know that we can use unittest in SikuliX.

I want to use unittest auto discovery feature in sikulix. I already put this inside my main sikulix script:

def suite():
    return unittest.TestLoader().discover(
        start_dir = ".",
        pattern = 'test_*.py'
    )

Now the problem is, I don't know how to call the auto discovery feature in sikulix. I run it using this

/Applications/Sikulix.app/run -r testdiscovery.sikuli

But it does not discover the files with the pattern defined (test_*.py).

So how should I run sikulix so I can call the unittest auto discovery feature?

Thank you for your kind helps.