[JingHao-Leon]

Description

An invalid loop_scope on the asyncio marker is validated with a bare assert, so a typo
is reported as a Python AssertionError printing a set repr:

@pytest.mark.asyncio(loop_scope="invalid_scope")
async def test_x():
    pass

E   AssertionError: assert 'invalid_scope' in {'class', 'function', 'module', 'package', 'session'}
ERROR test_bad.py - AssertionError: assert 'invalid_scope' in {'class', 'function', ...

The same mistake in asyncio_default_test_loop_scope already reads
ERROR: "bogus" is not a valid asyncio_default_test_loop_scope. Valid scopes are: function, class, module, package, session.

Both settings accept the same five scopes, and the plugin already has a helper that produces the
second message — the marker path just doesn't call it. The reported error also doesn't say which
argument was wrong.

This changes the reported message only; it does not change which inputs are accepted or rejected.

Root cause

pytest_asyncio/plugin.py:982-983, in _parse_asyncio_marker:

    if scope is not None:
        assert scope in {"function", "class", "module", "package", "session"}

This is the only validation of the marker's loop_scope/scope. pytest_configure validates
the two ini options through _validate_scope (pytest_asyncio/plugin.py:285), which raises
pytest.UsageError with the message above and returns early for None. Replacing the assert
with that call makes both paths use the same validation:

    _validate_scope(scope, "loop_scope")

Validation

tests/test_fixture_loop_scopes.py::test_invalid_marker_loop_scope_raises_error, added next to
the existing test_invalid_default_fixture_loop_scope_raises_error, which covers the ini-option
half of the same contract.

# before the fix
PYTHONPATH=$PWD python -m pytest tests/test_fixture_loop_scopes.py::test_invalid_marker_loop_scope_raises_error -q
1 failed          # reported: AssertionError: assert 'invalid_scope' in {...}

# after the fix
1 passed          # reported: pytest.UsageError: 'invalid_scope' is not a valid loop_scope.
                  #   Valid scopes are: function, class, module, package, session.

# full suite
PYTHONPATH=$PWD python -m pytest -q
296 passed, 3 skipped

Clean main baseline for comparison is 295 passed, 3 skipped; the one added test accounts for
the difference. No existing test changed behaviour.

Python 3.13.9, pytest 9.1.1. PYTHONPATH=$PWD is set because this machine also has
pytest-asyncio installed in site-packages; python -c "import pytest_asyncio; print(pytest_asyncio.__file__)"
resolves to the checkout under that path.

Fixes #1584

This change was prepared with the assistance of an AI coding agent.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.89%. Comparing base (93893ec) to head (9aa2fa5).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1585      +/-   ##
==========================================
+ Coverage   94.50%   94.89%   +0.38%     
==========================================
  Files           2        2              
  Lines         510      509       -1     
  Branches       62       61       -1     
==========================================
+ Hits          482      483       +1     
+ Misses         22       21       -1     
+ Partials        6        5       -1     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.