Update app.py

app.py

@@ -54,21 +54,31 @@ def tuples_from_messages(messages: List[Any]) -> List[List[str]]:
         return []
     # Already tuples-like
     if isinstance(messages[0], (list, tuple)) and len(messages[0]) == 2:
-        return [list(x) for x in messages]
+        out: List[List[str]] = []
+        for x in messages:
+            try:
+                a, b = x[0], x[1]
+            except Exception:
+                continue
+            out.append([str(a) if a is not None else "", str(b) if b is not None else ""])
+        return out
 
     # Convert from messages-style
     pairs: List[List[str]] = []
     last_user: Optional[str] = None
     for m in messages:
+        if not isinstance(m, dict):
+            # Skip any stray items
+            continue
         role = m.get("role")
         content = m.get("content", "")
         if role == "user":
-            last_user = content
+            last_user = str(content)
         elif role == "assistant":
             if last_user is None:
-                pairs.append(["", content])
+                pairs.append(["", str(content)])
             else:
-                pairs.append([last_user, content])
+                pairs.append([last_user, str(content)])
                 last_user = None
     if last_user is not None:
         pairs.append([last_user, ""])
@@ -81,7 +91,13 @@ def messages_from_tuples(history_tuples: List[List[str]]) -> List[Dict[str, str]
     [{"role": "user", ...}, {"role": "assistant", ...}, ...]
     """
     messages: List[Dict[str, str]] = []
-    for u, a in history_tuples:
+    for pair in history_tuples:
+        if not isinstance(pair, (list, tuple)) or len(pair) != 2:
+            # Skip malformed entries defensively
+            continue
+        u, a = pair
+        u = "" if u is None else str(u)
+        a = "" if a is None else str(a)
         if u:
             messages.append({"role": "user", "content": u})
         if a:
@@ -235,18 +251,20 @@ def clear_chat():
 
 def chat_fn(message, history, system_prompt, temperature, top_p):
     """Non-streaming chat handler (returns tuples)."""
-    history = tuples_from_messages(history)
+    history = tuples_from_messages(history or [])
     if not chat_model.model_loaded:
         return history + [[message, "Please wait for the model to load or reload the space."]]
 
     formatted_history = messages_from_tuples(history)
     response = chat_model.generate_once(message, formatted_history, system_prompt, temperature, MAX_NEW_TOKENS, top_p)
-    return history + [[message, response]]
+
+    # Always return strict [[str, str], ...]
+    return tuples_from_messages(history + [[message, response]])
 
 
 def chat_stream_fn(message, history, system_prompt, temperature, top_p):
     """Streaming chat handler: yields updated tuples as tokens arrive."""
-    history = tuples_from_messages(history)
+    history = tuples_from_messages(history or [])
     if not chat_model.model_loaded:
         yield history + [[message, "Please wait for the model to load or reload the space."]]
         return
@@ -256,7 +274,8 @@ def chat_stream_fn(message, history, system_prompt, temperature, top_p):
     # Start a new row for the assistant and fill progressively
     base = history + [[message, ""]]
     for chunk in chat_model.stream_generate(message, formatted_history, system_prompt, temperature, MAX_NEW_TOKENS, top_p):
-        yield base[:-1] + [[message, chunk]]
+        yield tuples_from_messages(base[:-1] + [[message, chunk]])
+    # Final state already yielded
     # Ensure completion (in case streamer ended exactly on boundary)
     # No extra yield needed; last chunk already yielded.
 
@@ -334,6 +353,7 @@ with gr.Blocks(
 
     chatbot = gr.Chatbot(
         type="tuples",
+        value=[],  # ensure initial value is a list of [user, assistant]
         label="Chat History",
         height=500,
         show_copy_button=True,
@@ -391,4 +411,4 @@ with gr.Blocks(
 demo.queue()
 
 if __name__ == "__main__":
-    demo.launch(show_error=True, debug=True)
+    demo.launch(show_error=True, debug=True)