Fix TODO: handle generic type parameters in _eval_nested_generic_alias

[AliiiBenn]

Status: NEEDS INVESTIGATION

Current Code Location

typemap/type_eval/_eval_typing.py, line 402-422

@_eval_types_impl.register
def _eval_nested_generic_alias(
    obj: _AssociatedTypeGenericAlias, ctx: EvalContext
):
    base, alias = obj.__args__

    # TODO: what if it has parameters of its own

    named_args = dict(
        zip(
            (p.__name__ for p in base.__origin__.__type_params__),
            base.__args__,
            strict=False,
        )
    )
    # ...

Question

The TODO asks: "what if it has parameters of its own?"

This refers to the case where base (the first argument to the associated type) is itself a generic class with type parameters.

Investigation Needed

1. What happens when base.__origin__.__type_params__ is not empty?
2. Are there existing test cases that trigger this code path?
3. Does the current implementation handle it correctly or is there a bug?

Suggested Approach

1. Add test cases that would trigger _eval_nested_generic_alias with parameterized generics
2. Verify if the current code handles this correctly
3. If not, implement the fix

Resolution

This issue requires investigation before implementing a fix.