Fixed bug in annotated.py where it used a stale copy of DEFAULT_ARGUMENT_PARSER.

Added test for set_default_argument_parser().

Author: kmvanbrunt

cmd2/annotated.py

@@ -212,7 +212,6 @@ def do_paint(
 
 from . import constants
 from .argparse_utils import (
-    DEFAULT_ARGUMENT_PARSER,
     ArgparseCommandSpec,
     Cmd2ArgumentParser,
     SubcommandSpec,
@@ -1968,7 +1967,9 @@ def build_parser_from_function(
     :param parser_kwargs: forwarded [`Cmd2ParserKwargs`][cmd2.annotated.Cmd2ParserKwargs]
     :return: a fully configured ``Cmd2ArgumentParser``
     """
-    parser_cls = parser_class or DEFAULT_ARGUMENT_PARSER
+    from . import argparse_utils
+
+    parser_cls = parser_class or argparse_utils.DEFAULT_ARGUMENT_PARSER
     if "description" not in parser_kwargs:
         auto_description = _docstring_first_paragraph(func.__doc__)
         if auto_description is not None:

tests/test_argparse_utils.py

@@ -863,3 +863,30 @@ def test_deprecated_subcommand() -> None:
     # Verify it was removed from _deprecated set
     assert "old" not in subparsers_action._deprecated  # type: ignore[attr-defined]
     assert "old_alias" not in subparsers_action._deprecated  # type: ignore[attr-defined]
+
+
+def test_set_default_argument_parser() -> None:
+    """Test altering the app-wide default Cmd2ArgumentParser class"""
+
+    class CustomParser(Cmd2ArgumentParser):
+        pass
+
+    try:
+        # Check the default parser type
+        assert argparse_utils.DEFAULT_ARGUMENT_PARSER is Cmd2ArgumentParser
+
+        default_app = cmd2.Cmd()
+        default_alias_parser = default_app.command_parsers.get(default_app.do_alias)
+        assert type(default_alias_parser) is Cmd2ArgumentParser
+
+        # Set a custom default parser type
+        argparse_utils.set_default_argument_parser(CustomParser)
+        assert argparse_utils.DEFAULT_ARGUMENT_PARSER is CustomParser
+
+        custom_app = cmd2.Cmd()
+        custom_alias_parser = custom_app.command_parsers.get(custom_app.do_alias)
+        assert type(custom_alias_parser) is CustomParser
+
+    finally:
+        # Restore the original parser
+        argparse_utils.set_default_argument_parser(Cmd2ArgumentParser)