Update chatStream.js

server/chatStream.js

@@ -183,7 +183,7 @@ export function extractSessionName(text) {
 export async function streamChat({
   sessionId,
   model,
-  history,
+  history = [],
   userMessage,
   tools,
   accessToken,
@@ -230,10 +230,9 @@ export async function streamChat({
   }
 
   const hasUserMessage =
-    userMessage !== undefined &&
-    userMessage !== null &&
-    userMessage !== "" &&
-    !(Array.isArray(userMessage) && userMessage.length === 0);
+      userMessage !== undefined &&
+      userMessage !== null &&
+      (typeof userMessage === "string" ? userMessage.trim() !== "" : Array.isArray(userMessage) && userMessage.length > 0);
 
   const messages = [
     { role: "system", content: SYSTEM_PROMPT },