Add Update.effective_sender (#4168)

telegram/_update.py

@@ -18,7 +18,7 @@
 # along with this program.  If not, see [http://www.gnu.org/licenses/].
 """This module contains an object that represents a Telegram Update."""
 
-from typing import TYPE_CHECKING, Final, List, Optional
+from typing import TYPE_CHECKING, Final, List, Optional, Union
 
 from telegram import constants
 from telegram._callbackquery import CallbackQuery
@@ -224,6 +224,7 @@ class Update(TelegramObject):
     __slots__ = (
         "_effective_chat",
         "_effective_message",
+        "_effective_sender",
         "_effective_user",
         "callback_query",
         "channel_post",
@@ -371,6 +372,7 @@ class Update(TelegramObject):
         self.message_reaction_count: Optional[MessageReactionCountUpdated] = message_reaction_count
 
         self._effective_user: Optional[User] = None
+        self._effective_sender: Optional[Union["User", "Chat"]] = None
         self._effective_chat: Optional[Chat] = None
         self._effective_message: Optional[Message] = None
 
@@ -444,6 +446,58 @@ class Update(TelegramObject):
         self._effective_user = user
         return user
 
+    @property
+    def effective_sender(self) -> Optional[Union["User", "Chat"]]:
+        """
+        :class:`telegram.User` or :class:`telegram.Chat`: The user or chat that sent this update,
+        no matter what kind of update this is.
+
+        Note:
+            * Depending on the type of update and the user's 'Remain anonymous' setting, this
+              could either be :class:`telegram.User`, :class:`telegram.Chat` or :obj:`None`.
+
+        If no user whatsoever is associated with this update, this gives :obj:`None`. This
+        is the case if any of
+
+        * :attr:`poll`
+        * :attr:`chat_boost`
+        * :attr:`removed_chat_boost`
+        * :attr:`message_reaction_count`
+
+        is present.
+
+        Example:
+            * If :attr:`message` is present, this will give either
+              :attr:`telegram.Message.from_user` or :attr:`telegram.Message.sender_chat`.
+            * If :attr:`poll_answer` is present, this will give either
+              :attr:`telegram.PollAnswer.user` or :attr:`telegram.PollAnswer.voter_chat`.
+            * If :attr:`channel_post` is present, this will give
+              :attr:`telegram.Message.sender_chat`.
+
+        .. versionadded:: NEXT.VERSION
+        """
+        if self._effective_sender:
+            return self._effective_sender
+
+        sender: Optional[Union["User", "Chat"]] = None
+
+        if message := (
+            self.message or self.edited_message or self.channel_post or self.edited_channel_post
+        ):
+            sender = message.sender_chat
+
+        elif self.poll_answer:
+            sender = self.poll_answer.voter_chat
+
+        elif self.message_reaction:
+            sender = self.message_reaction.actor_chat
+
+        if sender is None:
+            sender = self.effective_user
+
+        self._effective_sender = sender
+        return sender
+
     @property
     def effective_chat(self) -> Optional["Chat"]:
         """

tests/test_update.py

@@ -17,6 +17,7 @@
 # You should have received a copy of the GNU Lesser Public License
 # along with this program.  If not, see [http://www.gnu.org/licenses/].
 import time
+from copy import deepcopy
 from datetime import datetime
 
 import pytest
@@ -51,7 +52,21 @@ from telegram._utils.datetime import from_timestamp
 from telegram.warnings import PTBUserWarning
 from tests.auxil.slots import mro_slots
 
-message = Message(1, datetime.utcnow(), Chat(1, ""), from_user=User(1, "", False), text="Text")
+message = Message(
+    1,
+    datetime.utcnow(),
+    Chat(1, ""),
+    from_user=User(1, "", False),
+    text="Text",
+    sender_chat=Chat(1, ""),
+)
+channel_post = Message(
+    1,
+    datetime.utcnow(),
+    Chat(1, ""),
+    text="Text",
+    sender_chat=Chat(1, ""),
+)
 chat_member_updated = ChatMemberUpdated(
     Chat(1, "chat"),
     User(1, "", False),
@@ -93,6 +108,7 @@ message_reaction = MessageReactionUpdated(
     old_reaction=(ReactionTypeEmoji("👍"),),
     new_reaction=(ReactionTypeEmoji("👍"),),
     user=User(1, "name", False),
+    actor_chat=Chat(1, ""),
 )
 
 
@@ -108,8 +124,8 @@ params = [
     {"message": message},
     {"edited_message": message},
     {"callback_query": CallbackQuery(1, User(1, "", False), "chat", message=message)},
-    {"channel_post": message},
-    {"edited_channel_post": message},
+    {"channel_post": channel_post},
+    {"edited_channel_post": channel_post},
     {"inline_query": InlineQuery(1, User(1, "", False), "", "")},
     {"chosen_inline_result": ChosenInlineResult("id", User(1, "", False), "")},
     {"shipping_query": ShippingQuery("id", User(1, "", False), "", None)},
@@ -261,6 +277,76 @@ class TestUpdateWithoutRequest(TestUpdateBase):
         else:
             assert user is None
 
+    def test_effective_sender_non_anonymous(self, update):
+        update = deepcopy(update)
+        # Simulate 'Remain anonymous' being turned off
+        if message := (update.message or update.edited_message):
+            message._unfreeze()
+            message.sender_chat = None
+        elif reaction := (update.message_reaction):
+            reaction._unfreeze()
+            reaction.actor_chat = None
+        elif answer := (update.poll_answer):
+            answer._unfreeze()
+            answer.voter_chat = None
+
+        # Test that it's sometimes None per docstring
+        sender = update.effective_sender
+        if not (
+            update.poll is not None
+            or update.chat_boost is not None
+            or update.removed_chat_boost is not None
+            or update.message_reaction_count is not None
+        ):
+            if update.channel_post or update.edited_channel_post:
+                assert isinstance(sender, Chat)
+            else:
+                assert isinstance(sender, User)
+
+        else:
+            assert sender is None
+
+        cached = update.effective_sender
+        assert cached is sender
+
+    def test_effective_sender_anonymous(self, update):
+        update = deepcopy(update)
+        # Simulate 'Remain anonymous' being turned on
+        if message := (update.message or update.edited_message):
+            message._unfreeze()
+            message.from_user = None
+        elif reaction := (update.message_reaction):
+            reaction._unfreeze()
+            reaction.user = None
+        elif answer := (update.poll_answer):
+            answer._unfreeze()
+            answer.user = None
+
+        # Test that it's sometimes None per docstring
+        sender = update.effective_sender
+        if not (
+            update.poll is not None
+            or update.chat_boost is not None
+            or update.removed_chat_boost is not None
+            or update.message_reaction_count is not None
+        ):
+            if (
+                update.message
+                or update.edited_message
+                or update.channel_post
+                or update.edited_channel_post
+                or update.message_reaction
+                or update.poll_answer
+            ):
+                assert isinstance(sender, Chat)
+            else:
+                assert isinstance(sender, User)
+        else:
+            assert sender is None
+
+        cached = update.effective_sender
+        assert cached is sender
+
     def test_effective_message(self, update):
         # Test that it's sometimes None per docstring
         eff_message = update.effective_message