Warnings via parametrized tests are not displayed only once #4402
Description
It appears that "grouping" of warnings using "default", "once", or "module" has
no effect with warnings from parametrized tests:
import pytest
import warnings
def f():
warnings.warn("Foo")
@pytest.mark.parametrize('p', (1, 2))
def test_test(p):
f()% pytest -o 'filterwarnings=once' test_warn.py
==================================== test session starts ====================================
platform linux -- Python 3.6.7, pytest-4.0.0, py-1.7.0, pluggy-0.8.0
Django settings: project.settings (from environment variable)
rootdir: …/project/project, inifile: setup.cfg
plugins: requests-mock-1.5.2, xdist-1.24.1, mock-1.10.0, forked-0.2, django-3.4.4, cov-2.6.0, asyncio-0.9.0, celery-4.2.1
collected 2 items
test_warn.py .. [100%]
===================================== warnings summary ======================================
test_warn.py::test_test[1]
…/project/test_warn.py:6: UserWarning: Foo
warnings.warn("Foo")
test_warn.py::test_test[2]
…/project/test_warn.py:6: UserWarning: Foo
warnings.warn("Foo")
-- Docs: https://docs.pytest.org/en/latest/warnings.html
=========================== 2 passed, 2 warnings in 0.01 seconds ============================
I would expect the warning to appear only once.
From the warnings doc:
print only the first occurrence of matching warnings, regardless of location