Force List[Tuple[str,str]] to chat history widget (#12530)

Co-authored-by: Bagatur <baskaryan@gmail.com>

templates/rag-conversation/rag_conversation/chain.py

@@ -15,7 +15,7 @@ from langchain.schema.runnable import (
     RunnablePassthrough,
 )
 from langchain.vectorstores import Pinecone
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 if os.environ.get("PINECONE_API_KEY", None) is None:
     raise Exception("Missing `PINECONE_API_KEY` environment variable.")
@@ -87,7 +87,7 @@ def _format_chat_history(chat_history: List[Tuple[str, str]]) -> List:
 
 # User input
 class ChatHistory(BaseModel):
-    chat_history: List[Tuple[str, str]]
+    chat_history: List[Tuple[str, str]] = Field(..., extra={"widget": {"type": "chat"}})
     question: str