Register mypy_testing pytest marker

[MbappeWU]

Problem

pyproject.toml enables --strict-markers, and tests/test_typing.py uses @pytest.mark.mypy_testing. That marker is missing from the pytest markers list. The pytest-mypy-testing plugin registers it when the plugin is installed. Packagers often run the suite without that plugin. Collection then fails with 'mypy_testing' not found in markers configuration option.

Fix

Register mypy_testing in the markers list, with a short description in the same form as the existing entries.

Verification

Commands ran from the repo root in .venv on Python 3.13.5 and pytest 9.1.1.

Before the change, with pytest-mypy-testing uninstalled, .venv/bin/python -m pytest tests/test_typing.py exited 2. Collection reported 'mypy_testing' not found in markers configuration option.

Before the change, with pytest-mypy-testing 0.2.0 installed, the same command exited 0. 15 passed.

After the change, with the plugin uninstalled, .venv/bin/python -m pytest tests/test_typing.py exited 5. Pytest collected 0 tests and printed no marker error. Those functions are named mypy_*, so they are test items only when the plugin is installed. .venv/bin/python -m pytest exited 0. 695 passed, 1 skipped, 1 warning.

After the change, with pytest-mypy-testing 0.2.0 installed, .venv/bin/python -m pytest tests/test_typing.py exited 0. 15 passed. .venv/bin/python -m pytest exited 0. 710 passed, 1 skipped, 1 warning.

pre-commit run --files pyproject.toml passed (check toml, codespell, sp-repo-review and the other applicable hooks; Python/Markdown hooks had no files to check).

This change was prepared with AI assistance (Cursor CLI) and reviewed by me.

Fixes #889

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	⚠️ Failed 2026-10-11T10:22:19.708375Z	8c0d204	PR opened

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.20%. Comparing base (c4f1247) to head (8c0d204).

Components	Coverage Δ
traitlets	85.63% <ø> (ø)
tests	99.07% <ø> (ø)

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