chore: review comment and test

Author: KelvinChung2000

cmd2/annotated.py

@@ -635,6 +635,12 @@ def _resolve_parameters(
         if name in skip_params:
             continue
 
+        if param.kind == inspect.Parameter.POSITIONAL_ONLY:
+            raise TypeError(
+                f"Parameter {name!r} in {func.__qualname__} is positional-only, "
+                "which is not supported by @with_annotated because parameters are passed as keyword arguments."
+            )
+
         if name in _RESERVED_PARAM_NAMES:
             raise ValueError(
                 f"Parameter name {name!r} in {func.__qualname__} is reserved by argparse "

tests/test_annotated.py

@@ -117,6 +117,9 @@ def _func_grouped(
 ) -> None: ...
 
 
+def _func_positional_only(self, name: str, /) -> None: ...
+
+
 def _provider(cmd: cmd2.Cmd):
     return []
 
@@ -315,6 +318,10 @@ def func(self, subcommand: str) -> None: ...
         with pytest.raises(ValueError, match="subcommand"):
             build_parser_from_function(func)
 
+    def test_with_annotated_positional_only_param_raises(self) -> None:
+        with pytest.raises(TypeError, match="positional-only"):
+            build_parser_from_function(_func_positional_only)
+
     def test_optional_annotated_outside_raises(self) -> None:
         with pytest.raises(TypeError, match="Annotated"):
             build_parser_from_function(_func_optional_annotated_outside)