Fix Client.fetch_channel not returning Thread

discord/channel.py

@@ -691,7 +691,7 @@ class TextChannel(discord.abc.Messageable, discord.abc.GuildChannel, Hashable):
                 type=ChannelType.public_thread.value,
             )
 
-        return Thread(guild=self.guild, data=data)
+        return Thread(guild=self.guild, state=self._state, data=data)
 
     def archived_threads(
         self,
@@ -753,7 +753,7 @@ class TextChannel(discord.abc.Messageable, discord.abc.GuildChannel, Hashable):
         """
         data = await self._state.http.get_active_threads(self.id)
         # TODO: thread members?
-        return [Thread(guild=self.guild, data=d) for d in data.get('threads', [])]
+        return [Thread(guild=self.guild, state=self._state, data=d) for d in data.get('threads', [])]
 
 
 class VocalGuildChannel(discord.abc.Connectable, discord.abc.GuildChannel, Hashable):
@@ -1924,3 +1924,9 @@ def _channel_factory(channel_type: Union[ChannelType, int]):
         return GroupChannel, value
     else:
         return cls, value
+
+def _threaded_channel_factory(channel_type: Union[ChannelType, int]):
+    cls, value = _channel_factory(channel_type)
+    if value in (ChannelType.private_thread, ChannelType.public_thread, ChannelType.news_thread):
+        return Thread, value
+    return cls, value

discord/client.py

@@ -39,7 +39,7 @@ from .template import Template
 from .widget import Widget
 from .guild import Guild
 from .emoji import Emoji
-from .channel import _channel_factory
+from .channel import _threaded_channel_factory
 from .enums import ChannelType
 from .mentions import AllowedMentions
 from .errors import *
@@ -58,6 +58,7 @@ from .iterators import GuildIterator
 from .appinfo import AppInfo
 from .ui.view import View
 from .stage_instance import StageInstance
+from .threads import Thread
 
 if TYPE_CHECKING:
     from .abc import SnowflakeTime, PrivateChannel, GuildChannel, Snowflake
@@ -1371,10 +1372,10 @@ class Client:
         data = await self.http.get_user(user_id)
         return User(state=self._connection, data=data)
 
-    async def fetch_channel(self, channel_id: int) -> Union[GuildChannel, PrivateChannel]:
+    async def fetch_channel(self, channel_id: int) -> Union[GuildChannel, PrivateChannel, Thread]:
         """|coro|
 
-        Retrieves a :class:`.abc.GuildChannel` or :class:`.abc.PrivateChannel` with the specified ID.
+        Retrieves a :class:`.abc.GuildChannel`, :class:`.abc.PrivateChannel`, or :class:`.Thread` with the specified ID.
 
         .. note::
 
@@ -1395,12 +1396,12 @@ class Client:
 
         Returns
         --------
-        Union[:class:`.abc.GuildChannel`, :class:`.abc.PrivateChannel`]
+        Union[:class:`.abc.GuildChannel`, :class:`.abc.PrivateChannel`, :class:`.Thread`]
             The channel from the ID.
         """
         data = await self.http.get_channel(channel_id)
 
-        factory, ch_type = _channel_factory(data['type'])
+        factory, ch_type = _threaded_channel_factory(data['type'])
         if factory is None:
             raise InvalidData('Unknown channel type {type} for channel ID {id}.'.format_map(data))
 

discord/guild.py

@@ -287,7 +287,7 @@ class Guild(Hashable):
         self._members[member.id] = member
 
     def _store_thread(self, payload: ThreadPayload, /) -> Thread:
-        thread = Thread(guild=self, data=payload)
+        thread = Thread(guild=self, state=self._state, data=payload)
         self._threads[thread.id] = thread
         return thread
 
@@ -466,7 +466,7 @@ class Guild(Hashable):
         if 'threads' in data:
             threads = data['threads']
             for thread in threads:
-                self._add_thread(Thread(guild=self, data=thread))
+                self._add_thread(Thread(guild=self, state=self._state, data=thread))
 
     @property
     def channels(self) -> List[GuildChannel]:

discord/iterators.py

@@ -750,4 +750,4 @@ class ArchivedThreadIterator(_AsyncIterator['Thread']):
 
     def create_thread(self, data: ThreadPayload) -> Thread:
         from .threads import Thread
-        return Thread(guild=self.guild, data=data)
+        return Thread(guild=self.guild, state=self.guild._state, data=data)

discord/message.py

@@ -1491,7 +1491,7 @@ class Message(Hashable):
             auto_archive_duration=auto_archive_duration,
             type=ChannelType.public_thread.value,
         )
-        return Thread(guild=self.guild, data=data)  # type: ignore
+        return Thread(guild=self.guild, state=self._state, data=data)  # type: ignore
 
     async def reply(self, content: Optional[str] = None, **kwargs) -> Message:
         """|coro|

discord/state.py

@@ -715,7 +715,7 @@ class ConnectionState:
             log.debug('THREAD_CREATE referencing an unknown guild ID: %s. Discarding', guild_id)
             return
 
-        thread = Thread(guild=guild, data=data)
+        thread = Thread(guild=guild, state=guild._state, data=data)
         has_thread = guild.get_thread(thread.id)
         guild._add_thread(thread)
         if not has_thread:
@@ -735,7 +735,7 @@ class ConnectionState:
             thread._update(data)
             self.dispatch('thread_update', old, thread)
         else:
-            thread = Thread(guild=guild, data=data)
+            thread = Thread(guild=guild, state=guild._state, data=data)
             guild._add_thread(thread)
             self.dispatch('thread_join', thread)
 

discord/threads.py

@@ -139,8 +139,8 @@ class Thread(Messageable, Hashable):
         'archive_timestamp',
     )
 
-    def __init__(self, *, guild: Guild, data: ThreadPayload):
+    def __init__(self, *, guild: Guild, state: ConnectionState, data: ThreadPayload):
-        self._state: ConnectionState = guild._state
+        self._state: ConnectionState = state
         self.guild = guild
         self._members: Dict[int, ThreadMember] = {}
         self._from_data(data)