fix pure number message

src/utils.ts

@@ -43,7 +43,7 @@ export function adaptSession(bot: WeComBot, input: WecomEventResponse) {
     switch (body.MsgType) {
       case 'text':
         const textBody = body as WecomChatBody;
-        session.content = textBody.Content;
+        session.content = textBody.Content.toString();
         break;
       case 'image':
         const imageBody = body as WecomPicBody;