Change ValueError on max commands reached to a more specific exception

discord/app_commands/errors.py

@@ -38,6 +38,7 @@ __all__ = (
     'CommandAlreadyRegistered',
     'CommandSignatureMismatch',
     'CommandNotFound',
+    'MaxCommandsReached',
     'NoPrivateMessage',
     'MissingRole',
     'MissingAnyRole',
@@ -332,6 +333,39 @@ class CommandNotFound(AppCommandError):
         super().__init__(f'Application command {name!r} not found')
 
 
+class MaxCommandsReached(AppCommandError):
+    """An exception raised when the maximum number of application commands was reached
+    either globally or in a guild.
+
+    This inherits from :exc:`~discord.app_commands.AppCommandError`.
+
+    .. versionadded:: 2.0
+
+    Attributes
+    ------------
+    type: :class:`~discord.AppCommandType`
+        The type of command that reached the limit.
+    guild_id: Optional[:class:`int`]
+        The guild ID that reached the limit or ``None`` if it was global.
+    limit: :class:`int`
+        The limit that was hit.
+    """
+
+    def __init__(self, guild_id: Optional[int], limit: int, type: AppCommandType = AppCommandType.chat_input):
+        self.guild_id: Optional[int] = guild_id
+        self.limit: int = limit
+        self.type: AppCommandType = type
+
+        lookup = {
+            AppCommandType.chat_input: 'slash commands',
+            AppCommandType.message: 'message context menu commands',
+            AppCommandType.user: 'user context menu commands',
+        }
+        desc = lookup.get(type, 'application commands')
+        ns = 'globally' if self.guild_id is None else f'for guild ID {self.guild_id}'
+        super().__init__(f'maximum number of {desc} exceeded {limit} {ns}')
+
+
 class CommandSignatureMismatch(AppCommandError):
     """An exception raised when an application command from Discord has a different signature
     from the one provided in the code. This happens because your command definition differs

discord/app_commands/tree.py

@@ -55,6 +55,7 @@ from .errors import (
     CommandAlreadyRegistered,
     CommandNotFound,
     CommandSignatureMismatch,
+    MaxCommandsReached,
 )
 from ..errors import ClientException
 from ..enums import AppCommandType, InteractionType
@@ -194,7 +195,7 @@ class CommandTree(Generic[ClientT]):
 
         Raises
         --------
-        ValueError
+        MaxCommandsReached
             The maximum number of commands was reached for that guild.
             This is currently 100 for slash commands and 5 for context menu commands.
         """
@@ -206,7 +207,7 @@ class CommandTree(Generic[ClientT]):
 
         mapping.update(self._global_commands)
         if len(mapping) > 100:
-            raise ValueError('maximum number of slash commands exceeded (100)')
+            raise MaxCommandsReached(guild_id=guild.id, limit=100)
 
         ctx_menu: Dict[Tuple[str, Optional[int], int], ContextMenu] = {
             (name, guild.id, cmd_type): cmd
@@ -218,7 +219,7 @@ class CommandTree(Generic[ClientT]):
         for cmd_type, count in counter.items():
             if count > 5:
                 as_enum = AppCommandType(cmd_type)
-                raise ValueError(f'maximum number of context menu commands exceeded (5) for type {as_enum!s}')
+                raise MaxCommandsReached(guild_id=guild.id, limit=5, type=as_enum)
 
         self._context_menus.update(ctx_menu)
         self._guild_commands[guild.id] = mapping
@@ -261,7 +262,7 @@ class CommandTree(Generic[ClientT]):
         TypeError
             The application command passed is not a valid application command.
             Or, ``guild`` and ``guilds`` were both given.
-        ValueError
+        MaxCommandsReached
             The maximum number of commands was reached globally or for that guild.
             This is currently 100 for slash commands and 5 for context menu commands.
         """
@@ -284,7 +285,7 @@ class CommandTree(Generic[ClientT]):
 
                 total = sum(1 for _, g, t in self._context_menus if g == guild_id and t == type)
                 if total + found > 5:
-                    raise ValueError('maximum number of context menu commands exceeded (5)')
+                    raise MaxCommandsReached(guild_id=guild_id, limit=5, type=AppCommandType(type))
                 data[key] = command
 
             if guild_ids is None:
@@ -315,7 +316,7 @@ class CommandTree(Generic[ClientT]):
                 if found and not override:
                     raise CommandAlreadyRegistered(name, guild_id)
                 if len(commands) + found > 100:
-                    raise ValueError(f'maximum number of slash commands exceeded (100) for guild_id {guild_id}')
+                    raise MaxCommandsReached(guild_id=guild_id, limit=100)
 
             # Actually add the command now that it has been verified to be okay.
             for guild_id in guild_ids:
@@ -326,7 +327,7 @@ class CommandTree(Generic[ClientT]):
             if found and not override:
                 raise CommandAlreadyRegistered(name, None)
             if len(self._global_commands) + found > 100:
-                raise ValueError('maximum number of global slash commands exceeded (100)')
+                raise MaxCommandsReached(guild_id=None, limit=100)
             self._global_commands[name] = root
 
     @overload

docs/interactions/api.rst

@@ -575,6 +575,9 @@ Exceptions
 .. autoexception:: discord.app_commands.CommandOnCooldown
     :members:
 
+.. autoexception:: discord.app_commands.MaxCommandsReached
+    :members:
+
 .. autoexception:: discord.app_commands.CommandAlreadyRegistered
     :members:
 
@@ -600,6 +603,7 @@ Exception Hierarchy
                 - :exc:`~discord.app_commands.MissingPermissions`
                 - :exc:`~discord.app_commands.BotMissingPermissions`
                 - :exc:`~discord.app_commands.CommandOnCooldown`
+            - :exc:`~discord.app_commands.MaxCommandsReached`
             - :exc:`~discord.app_commands.CommandAlreadyRegistered`
             - :exc:`~discord.app_commands.CommandSignatureMismatch`
             - :exc:`~discord.app_commands.CommandNotFound`