Add Guild._fetch_role() private method to support proper handling of role mentionable in slash command options

discord/commands/core.py

@@ -50,7 +50,7 @@
 )
 
 from ..enums import ChannelType, SlashCommandOptionType
-from ..errors import ClientException, ValidationError
+from ..errors import ClientException, ValidationError, NotFound
 from ..member import Member
 from ..message import Attachment, Message
 from ..user import User
@@ -744,9 +744,10 @@ async def _invoke(self, ctx: ApplicationContext) -> None:
 
             elif op.input_type == SlashCommandOptionType.mentionable:
                 arg_id = int(arg)
-                arg = await get_or_fetch(ctx.guild, "member", arg_id)
-                if arg is None:
-                    arg = ctx.guild.get_role(arg_id) or arg_id
+                try:
+                    arg = await get_or_fetch(ctx.guild, "member", arg_id)
+                except NotFound:
+                    arg = await get_or_fetch(ctx.guild, "role", arg_id)
 
             elif op.input_type == SlashCommandOptionType.string and (converter := op.converter) is not None:
                 arg = await converter.convert(converter, ctx, arg)

discord/guild.py

@@ -2474,6 +2474,38 @@ async def fetch_roles(self) -> List[Role]:
         data = await self._state.http.get_roles(self.id)
         return [Role(guild=self, state=self._state, data=d) for d in data]
 
+    async def _fetch_role(self, role_id: int) -> Role:
+        """|coro|
+
+        Retrieves a :class:`Role` that the guild has.
+
+        .. note::
+
+            This method is an API call. For general usage, consider using :attr:`get_role` instead.
+
+        .. versionadded:: 2.0
+
+        Parameters
+        -----------
+        role_id: :class:`int`
+            The role ID to fetch from the guild.
+
+        Raises
+        -------
+        HTTPException
+            Retrieving the role failed.
+
+        Returns
+        -------
+        Optional[:class:`Role`]
+            The role in the guild with the specified ID.
+            Returns ``None`` if not found.
+        """
+        roles = await self.fetch_roles()
+        for role in roles:
+            if role.id == role_id:
+                return role
+
     @overload
     async def create_role(
         self,

discord/utils.py

@@ -377,7 +377,7 @@ def time_snowflake(dt: datetime.datetime, high: bool = False) -> int:
         The snowflake representing the time given.
     """
     discord_millis = int(dt.timestamp() * 1000 - DISCORD_EPOCH)
-    return (discord_millis << 22) + (2**22 - 1 if high else 0)
+    return (discord_millis << 22) + (2 ** 22 - 1 if high else 0)
 
 
 def find(predicate: Callable[[T], Any], seq: Iterable[T]) -> Optional[T]:
@@ -477,6 +477,8 @@ async def get_or_fetch(obj, attr: str, id: int, *, default: Any = MISSING):
     if getter is None:
         try:
             getter = await getattr(obj, f"fetch_{attr}")(id)
+        except AttributeError:
+            getter = await getattr(obj, f"_fetch_{attr}")(id)
         except HTTPException:
             if default is not MISSING:
                 return default