[commands] Automatically unload top level app commands in extensions

discord/ext/commands/bot.py

@@ -38,6 +38,7 @@ from typing import Any, Callable, Mapping, List, Dict, TYPE_CHECKING, Optional,
 import discord
 from discord import app_commands
 from discord.app_commands.tree import _retrieve_guild_ids
+from discord.utils import MISSING, _is_submodule
 
 from .core import GroupMixin
 from .view import StringView
@@ -65,8 +66,6 @@ __all__ = (
     'AutoShardedBot',
 )
 
-MISSING: Any = discord.utils.MISSING
-
 T = TypeVar('T')
 CFT = TypeVar('CFT', bound='CoroFunc')
 CXT = TypeVar('CXT', bound='Context')
@@ -120,10 +119,6 @@ def when_mentioned_or(*prefixes: str) -> Callable[[Union[Bot, AutoShardedBot], M
     return inner
 
 
-def _is_submodule(parent: str, child: str) -> bool:
-    return parent == child or child.startswith(parent + ".")
-
-
 class _DefaultRepr:
     def __repr__(self):
         return '<default-help-command>'
@@ -724,6 +719,9 @@ class BotBase(GroupMixin):
             for index in reversed(remove):
                 del event_list[index]
 
+        # remove all relevant application commands from the tree
+        self.__tree._remove_with_module(name)
+
     def _call_module_finalizers(self, lib: types.ModuleType, key: str) -> None:
         try:
             func = getattr(lib, 'teardown')

discord/ext/commands/cog.py

@@ -263,6 +263,8 @@ class Cog(metaclass=CogMeta):
         if cls.__cog_is_app_commands_group__:
             # Dynamic attribute setting
             self.__discord_app_commands_group_children__ = children  # type: ignore
+            # Enforce this to work even if someone forgets __init__
+            self.module = cls.__module__  # type: ignore
 
         return self