Fix channel deletion not removing associated threads

discord/guild.py

@@ -378,10 +378,11 @@ class Guild(Hashable):
     def _clear_threads(self) -> None:
         self._threads.clear()
 
-    def _remove_threads_by_channel(self, channel_id: int) -> None:
-        to_remove = [k for k, t in self._threads.items() if t.parent_id == channel_id]
-        for k in to_remove:
-            del self._threads[k]
+    def _remove_threads_by_channel(self, channel_id: int) -> List[Thread]:
+        to_remove = [t for t in self._threads.values() if t.parent_id == channel_id]
+        for thread in to_remove:
+            del self._threads[thread.id]
+        return to_remove
 
     def _filter_threads(self, channel_ids: Set[int]) -> Dict[int, Thread]:
         to_remove: Dict[int, Thread] = {k: t for k, t in self._threads.items() if t.parent_id in channel_ids}

discord/raw_models.py

@@ -33,6 +33,8 @@ from .app_commands import AppCommandPermissions
 from .colour import Colour
 
 if TYPE_CHECKING:
+    from typing_extensions import Self
+
     from .types.gateway import (
         MessageDeleteEvent,
         MessageDeleteBulkEvent as BulkMessageDeleteEvent,
@@ -399,6 +401,20 @@ class RawThreadDeleteEvent(_RawReprMixin):
         self.parent_id: int = int(data['parent_id'])
         self.thread: Optional[Thread] = None
 
+    @classmethod
+    def _from_thread(cls, thread: Thread) -> Self:
+        data: ThreadDeleteEvent = {
+            'id': thread.id,
+            'type': thread.type.value,
+            'guild_id': thread.guild.id,
+            'parent_id': thread.parent_id,
+        }
+
+        instance = cls(data)
+        instance.thread = thread
+
+        return instance
+
 
 class RawThreadMembersUpdate(_RawReprMixin):
     """Represents the payload for a :func:`on_raw_thread_member_remove` event.

discord/state.py

@@ -831,6 +831,12 @@ class ConnectionState(Generic[ClientT]):
                             guild._scheduled_events.pop(s.id)
                             self.dispatch('scheduled_event_delete', s)
 
+                threads = guild._remove_threads_by_channel(channel_id)
+
+                for thread in threads:
+                    self.dispatch('thread_delete', thread)
+                    self.dispatch('raw_thread_delete', RawThreadDeleteEvent._from_thread(thread))
+
     def parse_channel_update(self, data: gw.ChannelUpdateEvent) -> None:
         channel_type = try_enum(ChannelType, data.get('type'))
         channel_id = int(data['id'])