Fix ValueError when type annotations don't match function parameters

plumbum/cli/application.py

@@ -595,7 +595,7 @@ def _validate_args(
             for item, annotation in annotations.items():
                 if item == m.varargs:
                     varargs = annotation
-                elif item != "return":
+                elif item != "return" and item in args_names:
                     positional[args_names.index(item)] = annotation
 
             new_tailargs = self._positional_validate(

tests/test_cli_annotations.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from unittest.mock import patch
+
 from plumbum.cli import Application, ExistingFile
 
 
@@ -13,3 +15,33 @@ def test_access_annotations(capsys):
     assert rc == 0
     stdout, _ = capsys.readouterr()
     assert "file=pyproject.toml" in stdout
+
+
+def test_extra_annotations_ignored(capsys):
+    """Test that annotations not corresponding to parameters are safely ignored.
+
+    This test simulates a scenario where typing.get_type_hints returns
+    annotations that don't correspond to actual function parameters.
+    This could happen in edge cases with class-level annotations or
+    other advanced Python features. The code should handle this gracefully
+    by skipping annotations that aren't in the parameter list.
+    """
+    import typing
+
+    # Save the original get_type_hints
+    original_get_type_hints = typing.get_type_hints
+
+    def mock_get_type_hints(obj, *args, **kwargs):
+        hints = original_get_type_hints(obj, *args, **kwargs)
+        # Add an extra annotation that doesn't correspond to a parameter
+        # This simulates the condition that caused the original bug
+        if hasattr(obj, "__name__") and obj.__name__ == "main":
+            hints["FileArgument"] = ExistingFile
+        return hints
+
+    with patch("typing.get_type_hints", side_effect=mock_get_type_hints):
+        # This should not crash even with the extra annotation
+        _, rc = App.run(["prog", "pyproject.toml"], exit=False)
+        assert rc == 0
+        stdout, _ = capsys.readouterr()
+        assert "file=pyproject.toml" in stdout