Change abc.GuildChannel.overwrites to have Object keys if cache failed

Ultimately despite it not being the prettiest, Object keys ended up
being the sanest solution to this without destroying ergonomics.

discord/abc.py

@@ -471,6 +471,8 @@ class GuildChannel:
 
                 if isinstance(target, Role):
                     payload['type'] = _Overwrites.ROLE
+                elif isinstance(target, Object):
+                    payload['type'] = _Overwrites.ROLE if target.type is Role else _Overwrites.MEMBER
                 else:
                     payload['type'] = _Overwrites.MEMBER
 
@@ -548,14 +550,13 @@ class GuildChannel:
         """:class:`datetime.datetime`: Returns the channel's creation time in UTC."""
         return utils.snowflake_time(self.id)
 
-    def overwrites_for(self, obj: Union[Role, User]) -> PermissionOverwrite:
+    def overwrites_for(self, obj: Union[Role, User, Object]) -> PermissionOverwrite:
         """Returns the channel-specific overwrites for a member or a role.
 
         Parameters
         -----------
-        obj: Union[:class:`~discord.Role`, :class:`~discord.abc.User`]
-            The role or user denoting
-            whose overwrite to get.
+        obj: Union[:class:`~discord.Role`, :class:`~discord.abc.User`, :class:`~discord.Object`]
+            The role or user denoting whose overwrite to get.
 
         Returns
         ---------
@@ -579,16 +580,19 @@ class GuildChannel:
         return PermissionOverwrite()
 
     @property
-    def overwrites(self) -> Dict[Union[Role, Member], PermissionOverwrite]:
+    def overwrites(self) -> Dict[Union[Role, Member, Object], PermissionOverwrite]:
         """Returns all of the channel's overwrites.
 
         This is returned as a dictionary where the key contains the target which
         can be either a :class:`~discord.Role` or a :class:`~discord.Member` and the value is the
         overwrite as a :class:`~discord.PermissionOverwrite`.
 
+        .. versionchanged:: 2.0
+            Overwrites can now be type-aware :class:`~discord.Object` in case of cache lookup failure
+
         Returns
         --------
-        Dict[Union[:class:`~discord.Role`, :class:`~discord.Member`], :class:`~discord.PermissionOverwrite`]
+        Dict[Union[:class:`~discord.Role`, :class:`~discord.Member`, :class:`~discord.Object`], :class:`~discord.PermissionOverwrite`]
             The channel's permission overwrites.
         """
         ret = {}
@@ -603,13 +607,11 @@ class GuildChannel:
             elif ow.is_member():
                 target = self.guild.get_member(ow.id)
 
-            # TODO: There is potential data loss here in the non-chunked
-            # case, i.e. target is None because get_member returned nothing.
-            # This can be fixed with a slight breaking change to the return type,
-            # i.e. adding discord.Object to the list of it
-            # However, for now this is an acceptable compromise.
-            if target is not None:
-                ret[target] = overwrite
+            if target is None:
+                target_type = Role if ow.is_role() else User
+                target = Object(id=ow.id, type=target_type)  # type: ignore
+
+            ret[target] = overwrite
         return ret
 
     @property

discord/channel.py

@@ -38,6 +38,7 @@ from typing import (
     TYPE_CHECKING,
     Sequence,
     Tuple,
+    TypeVar,
     Union,
     overload,
 )
@@ -72,6 +73,7 @@ if TYPE_CHECKING:
 
     from .types.threads import ThreadArchiveDuration
     from .role import Role
+    from .object import Object
     from .member import Member, VoiceState
     from .abc import Snowflake, SnowflakeTime
     from .embeds import Embed
@@ -96,6 +98,8 @@ if TYPE_CHECKING:
     )
     from .types.snowflake import SnowflakeList
 
+    OverwriteKeyT = TypeVar('OverwriteKeyT', Role, BaseUser, Object, Union[Role, Member, Object])
+
 
 class ThreadWithMessage(NamedTuple):
     thread: Thread
@@ -293,7 +297,7 @@ class TextChannel(discord.abc.Messageable, discord.abc.GuildChannel, Hashable):
         slowmode_delay: int = ...,
         default_auto_archive_duration: ThreadArchiveDuration = ...,
         type: ChannelType = ...,
-        overwrites: Mapping[Union[Role, Member, Snowflake], PermissionOverwrite] = ...,
+        overwrites: Mapping[OverwriteKeyT, PermissionOverwrite] = ...,
     ) -> TextChannel:
         ...
 
@@ -1329,7 +1333,7 @@ class VoiceChannel(discord.abc.Messageable, VocalGuildChannel):
         position: int = ...,
         sync_permissions: int = ...,
         category: Optional[CategoryChannel] = ...,
-        overwrites: Mapping[Union[Role, Member], PermissionOverwrite] = ...,
+        overwrites: Mapping[OverwriteKeyT, PermissionOverwrite] = ...,
         rtc_region: Optional[str] = ...,
         video_quality_mode: VideoQualityMode = ...,
         reason: Optional[str] = ...,
@@ -1629,7 +1633,7 @@ class StageChannel(VocalGuildChannel):
         position: int = ...,
         sync_permissions: int = ...,
         category: Optional[CategoryChannel] = ...,
-        overwrites: Mapping[Union[Role, Member], PermissionOverwrite] = ...,
+        overwrites: Mapping[OverwriteKeyT, PermissionOverwrite] = ...,
         rtc_region: Optional[str] = ...,
         video_quality_mode: VideoQualityMode = ...,
         reason: Optional[str] = ...,
@@ -1802,7 +1806,7 @@ class CategoryChannel(discord.abc.GuildChannel, Hashable):
         name: str = ...,
         position: int = ...,
         nsfw: bool = ...,
-        overwrites: Mapping[Union[Role, Member], PermissionOverwrite] = ...,
+        overwrites: Mapping[OverwriteKeyT, PermissionOverwrite] = ...,
         reason: Optional[str] = ...,
     ) -> CategoryChannel:
         ...
@@ -2114,7 +2118,7 @@ class ForumChannel(discord.abc.GuildChannel, Hashable):
         slowmode_delay: int = ...,
         default_auto_archive_duration: ThreadArchiveDuration = ...,
         type: ChannelType = ...,
-        overwrites: Mapping[Union[Role, Member, Snowflake], PermissionOverwrite] = ...,
+        overwrites: Mapping[OverwriteKeyT, PermissionOverwrite] = ...,
     ) -> ForumChannel:
         ...
 

docs/migrating.rst

@@ -1119,6 +1119,7 @@ The following changes have been made:
 - :attr:`AuditLogEntry.target` may now be a :class:`PartialMessageable`.
 - :attr:`PartialMessage.channel` may now be a :class:`PartialMessageable`.
 - :attr:`Guild.preferred_locale` is now of type :class:`Locale`.
+- :attr:`abc.GuildChannel.overwrites` keys can now have :class:`Object` in them.
 
 Removals
 ----------