discord/ext/commands/bot.py

@@ -99,11 +99,13 @@ class _FakeSlashMessage(discord.PartialMessage):
     tts = False
 
     @classmethod
-    def from_interaction(cls, interaction: discord.Interaction) -> discord.Message:
-        self: discord.Message = cls(channel=interaction.channel, id=interaction.id)  # type: ignore
-
+    def from_interaction(
+        cls, interaction: discord.Interaction, channel: Union[discord.TextChannel, discord.DMChannel, discord.Thread]
+    ):
+        self = cls(channel=channel, id=interaction.id)
         assert interaction.user is not None
         self.author = interaction.user
+
         return self
 
 
@@ -233,7 +235,7 @@ class BotBase(GroupMixin):
             raise TypeError(f"owner_ids must be a collection not {self.owner_ids.__class__!r}")
 
         if not (message_commands or slash_commands):
-            raise TypeError("Both message_commands and slash_commands are disabled.")
+            raise ValueError("Both message_commands and slash_commands are disabled.")
 
         if help_command is _default:
             self.help_command = DefaultHelpCommand()
@@ -1259,11 +1261,8 @@ class BotBase(GroupMixin):
             else:
                 return  # cannot do anything without stable channel
 
-            interaction.channel = channel  # type: ignore
-        del channel
-
         # Fetch a valid prefix, so process_commands can function
-        message = _FakeSlashMessage.from_interaction(interaction)
+        message: discord.Message = _FakeSlashMessage.from_interaction(interaction, channel)  # type: ignore
         prefix = await self.get_prefix(message)
         if isinstance(prefix, list):
             prefix = prefix[0]

discord/ext/commands/core.py

@@ -429,7 +429,9 @@ class Command(_BaseCommand, Generic[CogT, P, T]):
         parent = kwargs.get("parent")
         self.parent: Optional[GroupMixin] = parent if isinstance(parent, _BaseCommand) else None  # type: ignore
         if self.slash_command_guilds is not None and self.parent is not None:
-            raise TypeError("Cannot set specific guilds for a subcommand. They are inherited from the top level group.")
+            raise ValueError(
+                "Cannot set specific guilds for a subcommand. They are inherited from the top level group."
+            )
 
         self._before_invoke: Optional[Hook] = None
         try: