tests-pytestlisted

# Backend tests: pytest (Python) Detect the test framework from the project: - `pytest.ini`, a `[tool.pytest.ini_options]` table in `pyproject.toml`, a `[pytest]` section in `setup.cfg`/`tox.ini`, or a `conftest.py` → **pytest**. - Only `unittest.TestCase` subclasses and no pytest configuration → the project is on stdlib `unittest`. Write `unittest` tests; pytest can still run them, but don't introduce pytest-only constructs into a suite that doesn't use it. ## Naming and layout pytest collects `test_*.py` and `*_test.py`, and within them `test_*` functions and `Test*` classes (which must have no `__init__`). Follow the project's existing choice between the two file spellings rather than mixing them. Both a `tests/` directory beside the package and tests colocated in the package are valid; match what is there. When `tests/` has no `__init__.py`, two test modules of the same basename in different directories collide under the default import mode — give them distinct names rather than adding `__init__.py` to a project that deliberately has none. ## Fixtures `conftest.py` is where shared fixtures live, and it applies to its directory and below — a fixture in the root `conftest.py` reaches every test. Prefer a narrow scope: put a fixture in the closest `conftest.py` that needs it. Fixture `scope=` (`function` by default, then `class`/`module`/`package`/`session`) decides how often setup runs, and a wider scope shares mutable state between tests. Widen it only for ge