Improve error msg in chat UI (#1557)

backend/danswer/chat/process_message.py

@@ -273,8 +273,8 @@ def stream_chat_message_objects(
                     "Be sure to update the chat pointers before calling this."
                 )
 
-            # Save now to save the latest chat message
-            db_session.commit()
+            # NOTE: do not commit user message - it will be committed when the
+            # assistant message is successfully generated
         else:
             # re-create linear history of messages
             final_msg, history_msgs = create_chat_chain(
@@ -304,6 +304,7 @@ def stream_chat_message_objects(
                     new_file.to_file_descriptor() for new_file in latest_query_files
                 ],
                 db_session=db_session,
+                commit=False,
             )
 
         selected_db_search_docs = None
@@ -362,7 +363,7 @@ def stream_chat_message_objects(
             # error=,
             # reference_docs=,
             db_session=db_session,
-            commit=True,
+            commit=False,
         )
 
         if not final_msg.prompt:
@@ -491,11 +492,19 @@ def stream_chat_message_objects(
                 yield cast(ChatPacket, packet)
 
     except Exception as e:
-        logger.exception(e)
+        logger.exception("Failed to process chat message")
 
-        # Frontend will erase whatever answer and show this instead
-        # This will be the issue 99% of the time
-        yield StreamingError(error="LLM failed to respond, have you set your API key?")
+        # Don't leak the API key
+        error_msg = str(e)
+        if llm.config.api_key and llm.config.api_key.lower() in error_msg.lower():
+            error_msg = (
+                f"LLM failed to respond. Invalid API "
+                f"key error from '{llm.config.model_provider}'."
+            )
+
+        yield StreamingError(error=error_msg)
+        # Cancel the transaction so that no messages are saved
+        db_session.rollback()
         return
 
     # Post-LLM answer processing
@@ -519,6 +528,7 @@ def stream_chat_message_objects(
             citations=db_citations,
             error=None,
         )
+        db_session.commit()  # actually save user / assistant message
 
         msg_detail_response = translate_db_message_to_chat_message_detail(
             gen_ai_response_message

web/src/app/chat/ChatPage.tsx

@@ -522,6 +522,9 @@ export function ChatPage({
       messageToResendParent ||
       (currMessageHistory.length > 0
         ? currMessageHistory[currMessageHistory.length - 1]
+        : null) ||
+      (completeMessageMap.size === 1
+        ? Array.from(completeMessageMap.values())[0]
         : null);
 
     // if we're resending, set the parent's child to null
@@ -684,14 +687,14 @@ export function ChatPage({
             message: currMessage,
             type: "user",
             files: currentMessageFiles,
-            parentMessageId: null,
+            parentMessageId: parentMessage?.messageId || SYSTEM_MESSAGE_ID,
           },
           {
             messageId: TEMP_ASSISTANT_MESSAGE_ID,
             message: errorMsg,
             type: "error",
             files: aiMessageImages || [],
-            parentMessageId: null,
+            parentMessageId: TEMP_USER_MESSAGE_ID,
           },
         ],
         completeMessageMapOverride: frozenCompleteMessageMap,

web/src/app/chat/message/Messages.tsx

@@ -113,7 +113,6 @@ export const AIMessage = ({
   if (!isReady) {
     return <div />;
   }
-  console.log(content);
 
   if (!isComplete) {
     const trimIncompleteCodeSection = (