Implement discord.Guild.get_or_fetch

discord/guild.py

@@ -37,6 +37,7 @@
     Optional,
     Sequence,
     Tuple,
+    TypeVar,
     Union,
     overload,
 )
@@ -895,6 +896,64 @@ def get_member(self, user_id: int, /) -> Member | None:
         """
         return self._members.get(user_id)
 
+    _FETCHABLE = TypeVar(
+        "_FETCHABLE",
+        bound=Union[
+            VoiceChannel,
+            TextChannel,
+            ForumChannel,
+            StageChannel,
+            CategoryChannel,
+            Thread,
+            Member,
+        ],
+    )
+
+    async def get_or_fetch(
+        self, object_type: Type[_FETCHABLE], object_id: int, /
+    ) -> _FETCHABLE | None:
+        """Shortcut method to get data from guild object if it's cached or fetch from api if it's not.
+
+        Parameters
+        ----------
+        object_type: :class:`Type[VoiceChannel, TextChannel, ForumChannel, StageChannel, CategoryChannel, Thread, Member]`
+            Type of object to fetch or get.
+
+        object_id: :class:`int`
+            ID of object to get.
+
+        Returns
+        -------
+
+        Optional[:class:`~Type[VoiceChannel, TextChannel, ForumChannel, StageChannel, CategoryChannel, Thread, Member]`]
+            The object of type that was specified or ``None`` if not found.
+
+        Usage
+        -----
+        ``await GUILD_OBJECT.get_or_fetch(OBJECT_TYPE, OBJECT_ID)``
+        """
+
+        def get_attr_name(t: object_type) -> str:
+            if t is Member:
+                return "member"
+            elif t in [
+                VoiceChannel,
+                TextChannel,
+                ForumChannel,
+                StageChannel,
+                CategoryChannel,
+                Thread,
+            ]:
+                return "channel"
+
+            raise InvalidArgument(
+                f"Class {object_type} cannot be used with discord.Guild.get_or_fetch()"
+            )
+
+        return await utils.get_or_fetch(
+            obj=self, attr=get_attr_name(object_type), id=object_id, default=None
+        )
+
     @property
     def premium_subscribers(self) -> list[Member]:
         """List[:class:`Member`]: A list of members who have "boosted" this guild."""