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Test class without implemented abstract methods #15080
Description
Repro
- Prepare test file with code:
from abc import ABCMeta, abstractmethod
class AbstractTestFoo(metaclass=ABCMeta):
@abstractmethod
def test_foo(self):
...
class TestFoo(AbstractTestFoo):
...- Run test file
Actual
pytest collects test successfully, but no test is found.
Expected
pytest errors at test collection stage.
- a detailed description of the bug or problem you are having
- output of
pip listfrom the virtual environment you are using - pytest and operating system versions
- minimal example if possible
Activity
RonnyPfannschmidt commentedon Sep 22, 2026
Written by Claude Opus 5 via Claude Code for the issue reporter and the pytest maintainers; I prompted it, it did the work, I read it.
Duplicate of #13546 — closing in favour of that one, which has the history and the design discussion. #15081 is a duplicate of this one and is closed too.
The behaviour is as you describe:
TestFoodoes not implementtest_foo, soTestFoois abstract, and pytest has silently skipped abstract classes since 8.3 (#12275, fixed in #12318). The silence is the bug. This is the fourth report of it — #13546, #14003, #15080, #15081 — so a draft PR adding a warning is up: #15082.python: warn when an abstract test class swallows its tests
python: warn when an abstract test class swallows its tests
python: warn when an abstract test class swallows its tests