Pytest 8.0.0rc1 stopped respecting usefixtures marker applied in pytest_itemcollected

[flying-sheep]

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In Pytest 7, adding a pytest.mark.usefixtures marker to a pytest.Item in pytest_itemcollected resulted in that marker being respected. With Pytest 8, that’s not the case.

The reproducer sets up two environments, one with Pytest 7.x, one with Pytest 8.0.0rc1, and runs a test suite:

reproducer

$ hatch run test
─────────────────────────────────────── 7 ───────────────────────────────────────
============================== test session starts ==============================
platform linux -- Python 3.11.6, pytest-7.4.3, pluggy-1.3.0 -- .../7/bin/python
cachedir: .pytest_cache
rootdir: .../pytest-8-doctests
collected 2 items                                                               

test_warnings.py::test_warnings.has_doctest PASSED                        [ 50%]
test_warnings.py::test_warn PASSED                                        [100%]

=============================== 2 passed in 0.01s ===============================

─────────────────────────────────────── 8 ───────────────────────────────────────
============================== test session starts ==============================
platform linux -- Python 3.11.6, pytest-8.0.0rc1, pluggy-1.3.0 -- .../8/bin/python
cachedir: .pytest_cache
rootdir: .../pytest-8-doctests
collected 2 items                                                               

test_warnings.py::test_warnings.has_doctest FAILED                        [ 50%]
test_warnings.py::test_warn PASSED                                        [100%]

=================================== FAILURES ====================================
______________________ [doctest] test_warnings.has_doctest ______________________
007 Doctest!
008     
009     >>> import warnings
010     >>> warnings.warn("Hi!", FutureWarning)
UNEXPECTED EXCEPTION: FutureWarning('Hi!')
Traceback (most recent call last):
  File "/usr/lib/python3.11/doctest.py", line 1351, in __run
    exec(compile(example.source, filename, "single",
  File "<doctest test_warnings.has_doctest[1]>", line 1, in <module>
FutureWarning: Hi!
.../pytest-8-doctests/test_warnings.py:10: UnexpectedException
============================ short test summary info ============================
FAILED test_warnings.py::test_warnings.has_doctest
========================== 1 failed, 1 passed in 0.01s ==========================

[bluetech]

Thanks for trying the release candidate! Will debug this soon.

[bluetech]

Bisected to ab63ebb.

[bluetech]

The commit made doctest items more similar to function items, which (unintentionally) had this effect. This is to say, adding usefixtures in pytest_itemcollected has never worked for function items, now it also doesn't work for doctest items.

Now the FuncFixtureInfo is fetched when the item is created (which is before pytest_itemcollected). This is what checks the usefixture marks. Previously getfixtureinfo was called on the doctest item's setup (after collection entirely).

Ideally this issue is resolved for both types of items.

[flying-sheep]

The commit made doctest items more similar to function items

sounds like a great idea, I had quite some problems with conflicts due to double importing modules. Would be great if #11475 could be fixed for 8.0 to nail down doctests once and for all.

adding usefixtures in pytest_itemcollected has never worked for function items, now it also doesn't work for doctest items.

of course the least surprising thing from an API standpoint would be to make it just work for all items, but as an alternative, having a blessed way to hook into doctest setup and teardown would also be great!

[bluetech]

@flying-sheep Instead of using the hook, could you maybe do this?

@pytest.fixture(autouse=True)
def suppress_env_for_doctests(request: pytest.FixtureRequest) -> None:
    if isinstance(request.node, pytest.DoctestItem):
        request.getfixturevalue("supress_env")