tweak check for batched prompt data

src/axolotl/prompt_strategies/bradley_terry/chat_template.py

@@ -21,6 +21,9 @@ class BTChatTemplateStrategy(ChatTemplateStrategy):
     Bradley-Terry reward model pairwise chat template prompt strategy.
     """
 
+    def is_prompt_batched(self, prompt: dict[str, Any]) -> bool:
+        return all(isinstance(v, list) for v in prompt.values())
+
     def _tokenize_single_prompt(self, prompt):
         """
 

src/axolotl/prompt_strategies/chat_template.py

@@ -226,12 +226,17 @@ class ChatTemplateStrategy(PromptTokenizingStrategy):
         # Let calling code know we can handle lists of examples
         return True
 
+    def is_prompt_batched(self, prompt: dict[str, Any]) -> bool:
+        return all(isinstance(v, list) for v in prompt.values()) and all(
+            isinstance(v, list) for v in prompt[self.messages]
+        )
+
     def tokenize_prompt(self, prompt: dict[str, Any]):
         """
         Public method that can handle either a single prompt or a batch of prompts.
         """
 
-        if not all(isinstance(v, list) for v in prompt.values()):
+        if not self.is_prompt_batched(prompt):
             return self._tokenize_single_prompt(prompt)
 
         res = defaultdict(lambda: [])