Handle all entity types on isinstance checks

Only the uses of `isinstance` against `InputPeer*` types were
reviewed. Notably, `utils` is exempt on this because it needs
to deal with everything on a case-by-case basis.

Since the addition of `*FromMessage` peers, any manual `isinstance`
checks to determine the type were prone to breaking or being
forgotten to be updated, so a common `helpers._entity_type()`
method was made to share this logic.

Since the conversion to `Peer` would be too expensive, a simpler
check against the name is made, which should be fast and cheap.

telethon/client/chats.py

@@ -108,8 +108,8 @@ class _ParticipantsIter(RequestIter):
                 filter = filter()
 
         entity = await self.client.get_input_entity(entity)
-        if search and (filter
-                       or not isinstance(entity, types.InputPeerChannel)):
+        ty = helpers._entity_type(entity)
+        if search and (filter or ty != helpers._EntityType.CHANNEL):
             # We need to 'search' ourselves unless we have a PeerChannel
             search = search.casefold()
 
@@ -123,7 +123,7 @@ class _ParticipantsIter(RequestIter):
         # Only used for channels, but we should always set the attribute
         self.requests = []
 
-        if isinstance(entity, types.InputPeerChannel):
+        if ty == helpers._EntityType.CHANNEL:
             self.total = (await self.client(
                 functions.channels.GetFullChannelRequest(entity)
             )).full_chat.participants_count
@@ -149,7 +149,7 @@ class _ParticipantsIter(RequestIter):
                     hash=0
                 ))
 
-        elif isinstance(entity, types.InputPeerChat):
+        elif ty == helpers._EntityType.CHAT:
             full = await self.client(
                 functions.messages.GetFullChatRequest(entity.chat_id))
             if not isinstance(
@@ -281,7 +281,8 @@ class _ProfilePhotoIter(RequestIter):
             self, entity, offset, max_id
     ):
         entity = await self.client.get_input_entity(entity)
-        if isinstance(entity, (types.InputPeerUser, types.InputPeerSelf)):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.USER:
             self.request = functions.photos.GetUserPhotosRequest(
                 entity,
                 offset=offset,
@@ -864,7 +865,8 @@ class ChatMethods:
         """
         entity = await self.get_input_entity(entity)
         user = await self.get_input_entity(user)
-        if not isinstance(user, (types.InputPeerUser, types.InputPeerSelf)):
+        ty = helpers._entity_type(user)
+        if ty != helpers._EntityType.USER:
             raise ValueError('You must pass a user entity')
 
         perm_names = (
@@ -872,7 +874,8 @@ class ChatMethods:
             'ban_users', 'invite_users', 'pin_messages', 'add_admins'
         )
 
-        if isinstance(entity, types.InputPeerChannel):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.CHANNEL:
             # If we try to set these permissions in a megagroup, we
             # would get a RIGHT_FORBIDDEN. However, it makes sense
             # that an admin can post messages, so we want to avoid the error
@@ -894,7 +897,7 @@ class ChatMethods:
                 for name in perm_names
             }), rank=title or ''))
 
-        elif isinstance(entity, types.InputPeerChat):
+        elif ty == helpers._EntityType.CHAT:
             # If the user passed any permission in a small
             # group chat, they must be a full admin to have it.
             if is_admin is None:
@@ -1015,7 +1018,8 @@ class ChatMethods:
                 await client.edit_permissions(chat, user)
         """
         entity = await self.get_input_entity(entity)
-        if not isinstance(entity, types.InputPeerChannel):
+        ty = helpers._entity_type(entity)
+        if ty != helpers._EntityType.CHANNEL:
             raise ValueError('You must pass either a channel or a supergroup')
 
         rights = types.ChatBannedRights(
@@ -1040,12 +1044,13 @@ class ChatMethods:
             ))
 
         user = await self.get_input_entity(user)
+        ty = helpers._entity_type(user)
+        if ty != helpers._EntityType.USER:
+            raise ValueError('You must pass a user entity')
+
         if isinstance(user, types.InputPeerSelf):
             raise ValueError('You cannot restrict yourself')
 
-        if not isinstance(user, types.InputPeerUser):
-            raise ValueError('You must pass a user entity')
-
         return await self(functions.channels.EditBannedRequest(
             channel=entity,
             user_id=user,
@@ -1086,12 +1091,13 @@ class ChatMethods:
         """
         entity = await self.get_input_entity(entity)
         user = await self.get_input_entity(user)
-        if not isinstance(user, (types.InputPeerUser, types.InputPeerSelf)):
+        if helpers._entity_type(user) != helpers._EntityType.USER:
             raise ValueError('You must pass a user entity')
 
-        if isinstance(entity, types.InputPeerChat):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.CHAT:
             await self(functions.messages.DeleteChatUserRequest(entity.chat_id, user))
-        elif isinstance(entity, types.InputPeerChannel):
+        elif ty == helpers._EntityType.CHANNEL:
             if isinstance(user, types.InputPeerSelf):
                 await self(functions.channels.LeaveChannelRequest(entity))
             else:

telethon/client/dialogs.py

@@ -3,7 +3,7 @@ import inspect
 import itertools
 import typing
 
-from .. import utils, hints
+from .. import helpers, utils, hints
 from ..requestiter import RequestIter
 from ..tl import types, functions, custom
 
@@ -436,10 +436,11 @@ class DialogMethods:
                 await client.delete_dialog('username')
         """
         entity = await self.get_input_entity(entity)
-        if isinstance(entity, types.InputPeerChannel):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.CHANNEL:
             return await self(functions.channels.LeaveChannelRequest(entity))
 
-        if isinstance(entity, types.InputPeerChat):
+        if ty == helpers._EntityType.CHAT:
             result = await self(functions.messages.DeleteChatUserRequest(
                 entity.chat_id, types.InputUserSelf()))
         else:

telethon/client/downloads.py

@@ -257,7 +257,8 @@ class DownloadMethods:
             # See issue #500, Android app fails as of v4.6.0 (1155).
             # The fix seems to be using the full channel chat photo.
             ie = await self.get_input_entity(entity)
-            if isinstance(ie, types.InputPeerChannel):
+            ty = helpers._entity_type(ie)
+            if ty == helpers._EntityType.CHANNEL:
                 full = await self(functions.channels.GetFullChannelRequest(ie))
                 return await self._download_photo(
                     full.full_chat.chat_photo, file,

telethon/client/messageparse.py

@@ -2,7 +2,7 @@ import itertools
 import re
 import typing
 
-from .. import utils
+from .. import helpers, utils
 from ..tl import types
 
 if typing.TYPE_CHECKING:
@@ -134,7 +134,7 @@ class MessageParseMethods:
                 id_to_message[update.message.id] = update.message
 
             elif (isinstance(update, types.UpdateEditMessage)
-                  and not isinstance(request.peer, types.InputPeerChannel)):
+                  and helpers._entity_type(request.peer) != helpers._EntityType.CHANNEL):
                 if request.id == update.message.id:
                     update.message._finish_init(self, entities, input_chat)
                     return update.message

telethon/client/messages.py

@@ -2,7 +2,7 @@ import inspect
 import itertools
 import typing
 
-from .. import utils, errors, hints
+from .. import helpers, utils, errors, hints
 from ..requestiter import RequestIter
 from ..tl import types, functions
 
@@ -57,8 +57,8 @@ class _MessagesIter(RequestIter):
 
         if from_user:
             from_user = await self.client.get_input_entity(from_user)
-            if not isinstance(from_user, (
-                    types.InputPeerUser, types.InputPeerSelf)):
+            ty = helpers._entity_type(from_user)
+            if ty != helpers._EntityType.USER:
                 from_user = None  # Ignore from_user unless it's a user
 
         if from_user:
@@ -86,8 +86,8 @@ class _MessagesIter(RequestIter):
                 filter = types.InputMessagesFilterEmpty()
 
             # Telegram completely ignores `from_id` in private chats
-            if isinstance(
-                    self.entity, (types.InputPeerUser, types.InputPeerSelf)):
+            ty = helpers._entity_type(self.entity)
+            if ty == helpers._EntityType.USER:
                 # Don't bother sending `from_user` (it's ignored anyway),
                 # but keep `from_id` defined above to check it locally.
                 from_user = None
@@ -246,6 +246,7 @@ class _IDsIter(RequestIter):
         self._ids = list(reversed(ids)) if self.reverse else ids
         self._offset = 0
         self._entity = (await self.client.get_input_entity(entity)) if entity else None
+        self._ty = helpers._EntityType(self._entity) if self._entity else None
 
         # 30s flood wait every 300 messages (3 requests of 100 each, 30 of 10, etc.)
         if self.wait_time is None:
@@ -259,7 +260,7 @@ class _IDsIter(RequestIter):
         self._offset += _MAX_CHUNK_SIZE
 
         from_id = None  # By default, no need to validate from_id
-        if isinstance(self._entity, (types.InputChannel, types.InputPeerChannel)):
+        if self._ty == helpers._EntityType.CHANNEL:
             try:
                 r = await self.client(
                     functions.channels.GetMessagesRequest(self._entity, ids))
@@ -1108,7 +1109,7 @@ class MessageMethods:
         )
 
         entity = await self.get_input_entity(entity) if entity else None
-        if isinstance(entity, types.InputPeerChannel):
+        if helpers._entity_type(entity) == helpers._EntityType.CHANNEL:
             return await self([functions.channels.DeleteMessagesRequest(
                          entity, list(c)) for c in utils.chunks(message_ids)])
         else:
@@ -1181,7 +1182,7 @@ class MessageMethods:
                 return True
 
         if max_id is not None:
-            if isinstance(entity, types.InputPeerChannel):
+            if helpers._entity_type(entity) == helpers._EntityType.CHANNEL:
                 return await self(functions.channels.ReadHistoryRequest(
                     utils.get_input_channel(entity), max_id=max_id))
             else:

telethon/client/users.py

@@ -4,7 +4,7 @@ import itertools
 import time
 import typing
 
-from .. import errors, utils, hints
+from .. import errors, helpers, utils, hints
 from ..errors import MultiError, RPCError
 from ..helpers import retry_range
 from ..tl import TLRequest, types, functions
@@ -258,12 +258,20 @@ class UserMethods:
             else:
                 inputs.append(await self.get_input_entity(x))
 
-        users = [x for x in inputs
-                 if isinstance(x, (types.InputPeerUser, types.InputPeerSelf))]
-        chats = [x.chat_id for x in inputs
-                 if isinstance(x, types.InputPeerChat)]
-        channels = [x for x in inputs
-                    if isinstance(x, types.InputPeerChannel)]
+        lists = {
+            helpers._EntityType.USER: [],
+            helpers._EntityType.CHAT: [],
+            helpers._EntityType.CHANNEL: [],
+        }
+        for x in inputs:
+            try:
+                lists[helpers._entity_type(x)].append(x)
+            except TypeError:
+                pass
+
+        users = lists[helpers._EntityType.USER]
+        chats = lists[helpers._EntityType.CHAT]
+        channels = lists[helpers._EntityType.CHANNEL]
         if users:
             # GetUsersRequest has a limit of 200 per call
             tmp = []