test_n_periods uses return instead of assert

[SaguaroDev]

Description

chainladder/development/tests/test_development.py::test_n_periods (line 40) ends with return xp.all(...) instead of assert xp.all(...). Pytest 9 emits a PytestReturnNotNoneWarning for this:

PytestReturnNotNoneWarning: Test functions should return None, but
chainladder/development/tests/test_development.py::test_n_periods returned <class 'numpy.bool'>.
Did you mean to use `assert` instead of `return`?

More importantly, the test currently does not actually fail when the equality breaks — it just returns a bool that pytest discards. This silently masks regressions in Development(n_periods=3, average='volume').

Reproduction

uv run pytest chainladder/development/tests/test_development.py::test_n_periods -W error::pytest.PytestReturnNotNoneWarning

Proposed fix

One-line change: replace return with assert on line 43. Outside the scope of #664 / #729 (this is a pytest issue, not a pandas 3.0 issue).

Note

This is the only test in the package with this bug — I grepped ^ return in test_*.py and the other 5 matches are all legitimate fixture returns. Happy to put up a PR.

[kennethshsu]

Hi @SaguaroDev, yes, do put up a PR!

[kennethshsu]

And may I suggest that we use the issue template next time? :)

[SaguaroDev]

This is the very first project that I'm contributing to.

Thank you for pointing me in the right direction, please bear with me.