[dividedmind]

Parameters with a default were only looked up in kwargs, so when passed positionally they were recorded as their default value, and the positional values spilled over into *args instead. E.g. for f(self, a, b=None) called as f('A', 'B'), b was recorded as None.

**kwargs was recorded as the full keyword argument dict, including arguments bound to named parameters. It now only contains the ones Python would actually put there. In particular, keyword arguments named like positional-only parameters now go to **kwargs rather than being recorded as the value of the positional-only parameter.

Assisted-by: Claude:claude-opus-5-5

[Copilot]

🟢 Approval recommended

No active review issues remain for the Python argument-recording changes.

No open issues 🎉

What changed in this PR

This PR corrects how AppMap records Python function arguments, aligning recorded parameter values with Python’s argument binding behavior.

Changes:

• Record optional parameters passed positionally without incorrectly including them in *args.
• Exclude named keyword parameters from recorded **kwargs, while preserving keywords that match positional-only parameter names.
• Add regression tests for mixed parameter kinds, defaults, and positional-only name collisions.

File	Description
_appmap/​test/​test_params.py	Adds regression tests for positional defaults and keyword argument binding.
_appmap/​test/​data/​params.py	Adds mixed-parameter and positional-only test fixtures.
_appmap/​event.py	Tracks positional-only parameters and corrects parameter value selection and **kwargs filtering.

_{Review effort: Balanced}