fix finish reason

Author: luukunn

fastdeploy/entrypoints/openai/serving_chat.py

@@ -325,7 +325,9 @@ async def chat_completion_stream_generator(
                             continue
                         delta_message.content = delta_message_output.content or ""
                         delta_message.reasoning_content = delta_message_output.reasoning_content or ""
-                        delta_message.tool_calls = delta_message_output.tool_calls
+                        if delta_message_output.tool_calls:
+                            delta_message.tool_calls = delta_message_output.tool_calls
+                            tool_called = True
 
                     choice = ChatCompletionResponseStreamChoice(
                         index=0,

fastdeploy/entrypoints/openai/serving_completion.py

@@ -418,7 +418,9 @@ async def completion_stream_generator(
                             continue
                         delta_message.text = delta_message_output.content or ""
                         delta_message.reasoning_content = delta_message_output.reasoning_content or ""
-                        delta_message.tool_calls = delta_message_output.tool_calls
+                        if delta_message_output.tool_calls:
+                            delta_message.tool_calls = delta_message_output.tool_calls
+                            tool_called[idx] = True
 
                     choices.append(delta_message)