chore: handle empty messages

Author: a-klos

libs/rag-core-api/src/rag_core_api/impl/graph/chat_graph.py

@@ -126,6 +126,13 @@ async def ainvoke(
         - The method processes the chat history based on the settings defined in `_chat_history_settings`.
         - The history is formatted and included in the `AnswerGraphState`.
         """
+        if not graph_input.message.strip():
+            return ChatResponse(
+                answer=self._error_messages.empty_message,
+                citations=[],
+                finish_reason=self._error_messages.empty_message,
+            )
+
         history_of_interest = []
         if graph_input.history and graph_input.history.messages:
             history_of_interest = graph_input.history.messages[-self._chat_history_settings.limit :]

libs/rag-core-api/src/rag_core_api/impl/settings/error_messages.py

@@ -18,6 +18,8 @@ class ErrorMessages(BaseSettings):
         Default message for harmful or inappropriate questions.
     no_answer_found : str
         Default message when no answer is found with the given context.
+    empty_message : str
+        Default message when an empty question is provided.
     """
 
     class Config:
@@ -40,3 +42,5 @@ class Config:
     no_answer_found: str = Field(
         default="Es tut mir leid, mit dem mir bereitgestellten Kontext konnte ich keine Antwort finden."
     )
+
+    empty_message: str = Field(default="Es tut mir leid, ich kann keine leere Frage beantworten.")