Remove exclude_unset parameter (#2654)

fastchat/serve/openai_api_server.py

@@ -452,7 +452,7 @@ async def chat_completion_stream_generator(
         chunk = ChatCompletionStreamResponse(
             id=id, choices=[choice_data], model=model_name
         )
-        yield f"data: {chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n"
+        yield f"data: {chunk.json(ensure_ascii=False)}\n\n"
 
         previous_text = ""
         async for content in generate_completion_stream(gen_params, worker_addr):
@@ -482,7 +482,7 @@ async def chat_completion_stream_generator(
                 if content.get("finish_reason", None) is not None:
                     finish_stream_events.append(chunk)
                 continue
-            yield f"data: {chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n"
+            yield f"data: {chunk.json(ensure_ascii=False)}\n\n"
     # There is not "content" field in the last delta message, so exclude_none to exclude field "content".
     for finish_chunk in finish_stream_events:
         yield f"data: {finish_chunk.json(exclude_none=True, ensure_ascii=False)}\n\n"
@@ -615,10 +615,10 @@ async def generate_completion_stream_generator(
                     if content.get("finish_reason", None) is not None:
                         finish_stream_events.append(chunk)
                     continue
-                yield f"data: {chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n"
+                yield f"data: {chunk.json(ensure_ascii=False)}\n\n"
     # There is not "content" field in the last delta message, so exclude_none to exclude field "content".
     for finish_chunk in finish_stream_events:
-        yield f"data: {finish_chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n"
+        yield f"data: {finish_chunk.json(exclude_none=True, ensure_ascii=False)}\n\n"
     yield "data: [DONE]\n\n"