fix: fix edge case on forward unresolveable type

[KelvinChung2000]

Fix an edge case when doing forward declaration on types:

  if TYPE_CHECKING:
      from myapp.cli import MyCmd

  @with_annotated
  def do_greet(self: "MyCmd", name: str, count: int = 1):
      ...

which happens when trying to declare the command in another file, while still wanting to keep the type hinting for self.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.40%. Comparing base (31d0461) to head (5a643fd).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1673      +/-   ##
==========================================
- Coverage   99.50%   99.40%   -0.11%     
==========================================
  Files          23       23              
  Lines        5689     5692       +3     
==========================================
- Hits         5661     5658       -3     
- Misses         28       34       +6     

Flag	Coverage Δ
unittests	99.40% <100.00%> (-0.11%)	⬇️

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[tleonhardt]

The one test failure is due to release of Python 3.15.0b2 and is fixed in PR #1674

[KelvinChung2000]

I will rebase once that is landed. I found another edge case related to the function return type that also needs to be covered

[tleonhardt]

If func is wrapped by another decorator using @functools.wraps, its __globals__ attribute points to the decorator's module, not the original function's module. Because globalns is explicitly provided here, get_type_hints() won't traverse the __wrapped__ chain to find the correct globals. This will cause forward references (e.g., string annotations) to fail with NameError or resolve to the wrong type.

Suggested change:

ignored = {next(iter(sig.parameters), None), *skip_params}
ignored.discard(None)
relevant_annotations = {name: ann for name, ann in getattr(func, "__annotations__", {}).items() if name not in ignored}
unwrapped = inspect.unwrap(func)
try:
    hints = get_type_hints(
        types.SimpleNamespace(__annotations__=relevant_annotations),
        globalns=getattr(unwrapped, "__globals__", {}),
        include_extras=True,
    )

The key change is created unrwapped = inspect.unwrap(func) before the try and then using unwrapped instead of func in the call to getattr.

[tleonhardt]

@KelvinChung2000 I merged the fix for Python 3.15.0b2. You are free to rebase when you see fit.