Make the bot auto-join threads

1 files changed, 17 insertions, 1 deletions

diff --git a/bot/exts/utils/bot.py b/bot/exts/utils/bot.py
index d84709616..f3a7206fc 100644
--- a/bot/exts/utils/bot.py
+++ b/bot/exts/utils/bot.py
@@ -1,7 +1,8 @@
 import logging
+from contextlib import suppress
 from typing import Optional
 
-from discord import Embed, TextChannel
+from discord import Embed, Forbidden, TextChannel, Thread
 from discord.ext.commands import Cog, Context, command, group, has_any_role
 
 from bot.bot import Bot
@@ -16,6 +17,21 @@ class BotCog(Cog, name="Bot"):
     def __init__(self, bot: Bot):
         self.bot = bot
 
+    @Cog.listener()
+    async def on_thread_join(self, thread: Thread) -> None:
+        """
+        Try to join newly created threads.
+
+        Despite the event name being misleading, this is dispatched when new threads are created.
+        We want our bots to automatically join threads in order to answer commands using their prefixes.
+        """
+        if thread.me:
+            # Already in this thread, return early
+            return
+
+        with suppress(Forbidden):
+            await thread.join()
+
     @group(invoke_without_command=True, name="bot", hidden=True)
     async def botinfo_group(self, ctx: Context) -> None:
         """Bot informational commands."""