pytest 9.0 errors instead of skipping when `unittest.SkipTest` is raised

[progval]

This code:

import unittest

def test_skiptest():
    raise unittest.SkipTest()

had this behavior on pytest <9.0:

$ rm venv -r
$ python3 -m venv ./venv
$ ./venv/bin/pip install "pytest<9"
[...]
Successfully installed iniconfig-2.3.0 packaging-25.0 pluggy-1.6.0 pygments-2.19.2 pytest-8.4.2
$ ./venv/bin/pytest test.py
=== test session starts ===
platform linux -- Python 3.13.5, pytest-8.4.2, pluggy-1.6.0
rootdir: /home/dev-irc
collected 1 item
test.py s        [100%]

=== 1 skipped in 0.03s ===

and this on pytest 9.0.0:

$ rm venv -r
$ python3 -m venv ./venv
$ ./venv/bin/pip install "pytest==9.0.0"
[...]
Successfully installed iniconfig-2.3.0 packaging-25.0 pluggy-1.6.0 pygments-2.19.2 pytest-9.0.0
$ ./venv/bin/pytest test.py
=== test session starts ===
platform linux -- Python 3.13.5, pytest-9.0.0, pluggy-1.6.0
rootdir: /home/dev-irc
collected 1 item
test.py F       [100%]

==== FAILURES ===
____ test_skiptest ____

    def test_skiptest():
>       raise unittest.SkipTest()
E       unittest.case.SkipTest

test.py:3: SkipTest
=== short test summary info ===
FAILED test.py::test_skiptest - unittest.case.SkipTest
=== 1 failed in 0.06s ===

Python version: 3.13.5

[bluetech]

Thanks for the report.

Bisected to a620d24 (@nicoddemus).

However, you raising a unittest exception in a non-unittest test, is there a reason for that? Can you use pytest.skip() instead?

[bluetech]

Just to clarify my comment, raising unittest.SkipTest still works inside a unittest TestCase.

[progval]

It's inherited from before I used pytest.

I actually use subclasses of unittest.SkipTest and I don't think I ever try to catch them in an except block so I should be able to convert them to functions wrapping pytest.skip(). But I imagine someone else might not.

[progval]

Also, I have people not familiar with pytest on this codebase, and raise MySkipTestSubclass() probably makes the control flow clearer for them than calling my_pytestdotskip_wrapper()

[nicoddemus]

Looking at the commit, this worked before due to nose support, which has since then been removed.

I don't think we should continue to support this usage, TBH. Seems simple enough for users to adapt this code to use pytest.skip() instead.

What do you folks think?

[mkmoisen]

@bluetech

raising unittest.SkipTest still works inside a unittest TestCase.

That is not the case for me now in 9.0.0.

Raising unittest.SkipTest inside of unittest.TestCase is resulting in pytests reporting an error instead of a skip.

class TestFoo(unittest.TestCase):
@classmethod
    def setUpClass(cls):
        if cls is Bar:
            raise unittest.SkipTest('Skip Bar tests as it is a base class')

[mkmoisen]

@nicoddemus

Please see my comment above. unittest.SkipTest is broken for me now when using it in a unittest.TestCase.

Thank you.

[nicoddemus]

Please see my comment above. unittest.SkipTest is broken for me now when using it in a unittest.TestCase.

Oh if that's the case then definitely this is a problem. I will look into it, thanks!

[Berserker66]

Yeah, chiming in from a project where pytest is entirely optional, everything is defined with pure unittest and people can run pytest over it if they want. The skips result in errors now when using pytest, but not when using the python included unittest runner.

[Zac-HD]

Being able to raise unittest.SkipTest() without worrying about whether my users are running pytest or unittest is nice for other testing libraries like Hypothesis too, so I'd support restoring the old behavior 🙂