Fixed issue where instantiating more than one cmd2-based class which uses the @as_subcommand_toduplicate_subcommand

decorator resulted in duplicated help text in the base command the subcommands belong to.

3 files changed, 23 insertions, 11 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e2ada12f..1b41df31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 * Bug Fixes
     * Fixed issue where quoted redirectors and terminators in aliases and macros were not being
     restored when read from a startup script.
+    * Fixed issue where instantiating more than one cmd2-based class which uses the `@as_subcommand_to`
+    decorator resulted in duplicated help text in the base command the subcommands belong to.
 
 ## 1.3.10 (September 17, 2020)
 * Enhancements
diff --git a/cmd2/argparse_custom.py b/cmd2/argparse_custom.py
index 45abe6b2..d773f851 100644
--- a/cmd2/argparse_custom.py
+++ b/cmd2/argparse_custom.py
@@ -550,6 +550,7 @@ argparse.ArgumentParser._match_argument = _match_argument_wrapper
 # Patch argparse._SubParsersAction to add remove_parser function
 ############################################################################################################
 
+# noinspection PyPep8Naming
 def _SubParsersAction_remove_parser(self, name: str):
     """
     Removes a sub-parser from a sub-parsers group
@@ -558,23 +559,23 @@ def _SubParsersAction_remove_parser(self, name: str):
     class so cmd2 can remove subcommands from a parser.
 
     :param self: instance of the _SubParsersAction being edited
-    :param name: name of the sub-parser to remove
+    :param name: name of the subcommand for the sub-parser to remove
     """
+    # Remove this subcommand from its base command's help text
     for choice_action in self._choices_actions:
         if choice_action.dest == name:
             self._choices_actions.remove(choice_action)
             break
 
-    subparser = self._name_parser_map[name]
-    to_remove = []
-    for name, parser in self._name_parser_map.items():
-        if parser is subparser:
-            to_remove.append(name)
-    for name in to_remove:
-        del self._name_parser_map[name]
-
-    if name in self.choices:
-        del self.choices[name]
+    # Remove this subcommand and all its aliases from the base command
+    subparser = self._name_parser_map.get(name)
+    if subparser is not None:
+        to_remove = []
+        for cur_name, cur_parser in self._name_parser_map.items():
+            if cur_parser is subparser:
+                to_remove.append(cur_name)
+        for cur_name in to_remove:
+            del self._name_parser_map[cur_name]
 
 
 # noinspection PyProtectedMember
@@ -733,6 +734,7 @@ class Cmd2HelpFormatter(argparse.RawTextHelpFormatter):
                 return ', '.join(action.option_strings) + ' ' + args_string
             # End cmd2 customization
 
+    # noinspection PyMethodMayBeStatic
     def _determine_metavar(self, action, default_metavar) -> Union[str, Tuple]:
         """Custom method to determine what to use as the metavar value of an action"""
         if action.metavar is not None:
diff --git a/cmd2/cmd2.py b/cmd2/cmd2.py
index 8810025a..ea4e01de 100644
--- a/cmd2/cmd2.py
+++ b/cmd2/cmd2.py
@@ -692,6 +692,14 @@ class Cmd(cmd.Cmd):
 
             for action in target_parser._actions:
                 if isinstance(action, argparse._SubParsersAction):
+                    # Temporary workaround for avoiding subcommand help text repeatedly getting added to
+                    # action._choices_actions. Until we have instance-specific parser objects, we will remove
+                    # any existing subcommand which has the same name before replacing it. This problem is
+                    # exercised when more than one cmd2.Cmd-based object is created and the same subcommands
+                    # get added each time. Argparse overwrites the previous subcommand but keeps growing the help
+                    # text which is shown by running something like 'alias -h'.
+                    action.remove_parser(subcommand_name)
+
                     # Get the kwargs for add_parser()
                     add_parser_kwargs = getattr(method, constants.SUBCMD_ATTR_ADD_PARSER_KWARGS, {})