[chiliec]

Fixes #16657

ttk.OptionMenu currently types command as Callable[[tkinter.StringVar], object] | None, but at runtime the callback is invoked with the selected string value, not the StringVar. In CPython's tkinter/ttk.py, set_menu does:

command=(None if self._callback is None else lambda val=val: self._callback(val))

where val comes from *values (strings). So a valid Callable[[str], object] handler is wrongly rejected by the stub. tkinter.OptionMenu already annotates command as Callable[[str], object] | None; this change makes ttk.OptionMenu consistent (both the 3.14+ and the older signature).

Tests

Added an OptionMenu case to stdlib/@tests/test_cases/check_tkinter.py for both tkinter.OptionMenu and tkinter.ttk.OptionMenu.

Validation (mypy 2.4.0, --custom-typeshed-dir .):

• Before the stub fix, the test case errored:
  error: Argument "command" to "OptionMenu" has incompatible type "Callable[[str], None]"; expected "Callable[[StringVar], object] | None" [arg-type]
• After the fix, check_tkinter.py passes clean under both --python-version 3.14 and --python-version 3.12.

[srittau]

Please remove the tests. In typeshed, we only add regression tests for functions and classes which are known to have caused complex problems in the past, or where stubs are difficult to get right. 100% test coverage for typeshed is neither necessary nor desirable, as it would lead to code duplication.

See tests/REGRESSION.md for more information.

[chiliec]

Done — removed the test case, the PR is now just the stub change in ttk.pyi (4ace347). Thanks for the pointer to REGRESSION.md.

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉