fix #2438

Former-commit-id: 412d856eeada2abcea598fac0a8d35ae90cc9c01

src/llmtuner/chat/chat_model.py

@@ -94,6 +94,9 @@ class ChatModel:
         tools: Optional[str] = None,
         **input_kwargs,
     ) -> List[Response]:
+        if not self.can_generate:
+            raise ValueError("The current model does not support `chat`.")
+
         gen_kwargs, prompt_length = self._process_args(messages, system, tools, **input_kwargs)
         generate_output = self.model.generate(**gen_kwargs)
         response_ids = generate_output[:, prompt_length:]
@@ -123,6 +126,9 @@ class ChatModel:
         tools: Optional[str] = None,
         **input_kwargs,
     ) -> Generator[str, None, None]:
+        if not self.can_generate:
+            raise ValueError("The current model does not support `stream_chat`.")
+
         gen_kwargs, _ = self._process_args(messages, system, tools, **input_kwargs)
         streamer = TextIteratorStreamer(self.tokenizer, timeout=60.0, skip_prompt=True, skip_special_tokens=True)
         gen_kwargs["streamer"] = streamer
@@ -134,9 +140,11 @@ class ChatModel:
 
     @torch.inference_mode()
     def get_scores(self, batch_input: List[str], **input_kwargs) -> List[float]:
+        if self.can_generate:
+            raise ValueError("Cannot get scores using an auto-regressive model.")
+
         max_length = input_kwargs.pop("max_length", None)
         device = getattr(self.model.pretrained_model, "device", "cuda")
-
         inputs = self.tokenizer(
             batch_input,
             padding=True,