From 3536bb247eb3ce9d933af6b933c373c4b0456521 Mon Sep 17 00:00:00 2001
From: Harshil <37377066+harshil21@users.noreply.github.com>
Date: Sat, 17 Sep 2022 01:43:11 +0530
Subject: [PATCH] Improve Warning About Unknown `ConversationHandler` States
 (#3242)

---
 telegram/ext/_conversationhandler.py | 11 +++++++----
 tests/test_conversationhandler.py    |  2 +-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/telegram/ext/_conversationhandler.py b/telegram/ext/_conversationhandler.py
index 6873c94af..715dac72e 100644
--- a/telegram/ext/_conversationhandler.py
+++ b/telegram/ext/_conversationhandler.py
@@ -855,13 +855,13 @@ class ConversationHandler(BaseHandler[Update, CCT]):
                         )
 
         if isinstance(self.map_to_parent, dict) and new_state in self.map_to_parent:
-            self._update_state(self.END, conversation_key)
+            self._update_state(self.END, conversation_key, handler)
             if raise_dp_handler_stop:
                 raise ApplicationHandlerStop(self.map_to_parent.get(new_state))
             return self.map_to_parent.get(new_state)
 
         if current_state != self.WAITING:
-            self._update_state(new_state, conversation_key)
+            self._update_state(new_state, conversation_key, handler)
 
         if raise_dp_handler_stop:
             # Don't pass the new state here. If we're in a nested conversation, the parent is
@@ -870,7 +870,9 @@ class ConversationHandler(BaseHandler[Update, CCT]):
         # Signals a possible parent conversation to stay in the current state
         return None
 
-    def _update_state(self, new_state: object, key: ConversationKey) -> None:
+    def _update_state(
+        self, new_state: object, key: ConversationKey, handler: BaseHandler = None
+    ) -> None:
         if new_state == self.END:
             if key in self._conversations:
                 # If there is no key in conversations, nothing is done.
@@ -884,7 +886,8 @@ class ConversationHandler(BaseHandler[Update, CCT]):
         elif new_state is not None:
             if new_state not in self.states:
                 warn(
-                    f"BaseHandler returned state {new_state} which is unknown to the "
+                    f"{repr(handler.callback.__name__) if handler is not None else 'BaseHandler'} "
+                    f"returned state {new_state} which is unknown to the "
                     f"ConversationHandler{' ' + self.name if self.name is not None else ''}.",
                     stacklevel=2,
                 )
diff --git a/tests/test_conversationhandler.py b/tests/test_conversationhandler.py
index 86ef2ad24..2e8b3064f 100644
--- a/tests/test_conversationhandler.py
+++ b/tests/test_conversationhandler.py
@@ -670,7 +670,7 @@ class TestConversationHandler:
                 raise exc
             assert len(recwarn) == 1
             assert str(recwarn[0].message) == (
-                "BaseHandler returned state 69 which is unknown to the ConversationHandler xyz."
+                "'callback' returned state 69 which is unknown to the ConversationHandler xyz."
             )
 
     async def test_conversation_handler_per_chat(self, app, bot, user1, user2):