optimize error response in streaming

src/api/models/base.py

@@ -11,6 +11,7 @@ from api.schema import (
     # Embeddings
     EmbeddingsRequest,
     EmbeddingsResponse,
+    Error,
 )
 
 
@@ -43,14 +44,19 @@ class BaseChatModel(ABC):
         return "chatcmpl-" + str(uuid.uuid4())[:8]
 
     @staticmethod
-    def stream_response_to_bytes(response: ChatStreamResponse | None = None) -> bytes:
-        if response:
+    def stream_response_to_bytes(response: ChatStreamResponse | Error | None = None) -> bytes:
+        if isinstance(response, Error):
+            data = response.model_dump_json()
+        elif isinstance(response, ChatStreamResponse):
             # to populate other fields when using exclude_unset=True
             response.system_fingerprint = "fp"
             response.object = "chat.completion.chunk"
             response.created = int(time.time())
-            return "data: {}\n\n".format(response.model_dump_json(exclude_unset=True)).encode("utf-8")
-        return "data: [DONE]\n\n".encode("utf-8")
+            data = response.model_dump_json(exclude_unset=True)
+        else:
+            data = "[DONE]"
+
+        return f"data: {data}\n\n".encode("utf-8")
 
 
 class BaseEmbeddingsModel(ABC):