[Yash990-bit]

Close #166

Summary

Fixes a false positive in plugin-activation-args where activation functions using default parameter values (e.g. trans: ITranslator | null = null) were erroneously reported for missing arguments and incorrect argument counts.

Background & Cause

In src/rules/plugin-activation-args.ts, extractFunctionInfo filtered fn.params with:

const params = fn.params.filter(
  (param): param is TSESTree.Identifier => param.type === 'Identifier'
);

[Copilot]

🟡 Changes recommended

The initializer shortcut incorrectly suppresses optionalNotNullable for explicitly non-nullable parameters, allowing the activation body to receive a missing service while assuming a non-nullable type.

1 open issue

• Remove initializer shortcut suppressing optionalNotNullable · New

What changed in this PR

This PR addresses #166 by teaching plugin-activation-args to recognize defaulted activation parameters, avoiding false missing-argument and argument-count reports.

Changes:

• Extract parameter names and types from default-value assignments while preserving parameter positions.
• Add initializer-based nullability handling.
• Add regression tests for defaulted parameters, referenced functions, method shorthand, and invalid token types or ordering.

File	Description
tests/​jupyter-plugin-activation-args.test.ts	Adds valid and invalid cases covering defaulted activation parameters.
src/​rules/​plugin-activation-args.ts	Handles defaulted parameters during extraction and updates nullability checks.

_{Review effort: Balanced}