frontend: improve empty result handling

frontend/telegram_bot.go

@@ -145,7 +145,10 @@ func webHandlerTelegramBot(w http.ResponseWriter, r *http.Request) {
 	}
 
 	commandResult = strings.TrimSpace(commandResult)
-	if len(commandResult) > 0 {
+	if len(commandResult) < 0 {
+		commandResult = "empty result"
+	}
+
 	// Create a JSON response
 	w.Header().Add("Content-Type", "application/json")
 	response := &tgWebhookResponse{
@@ -162,5 +165,4 @@ func webHandlerTelegramBot(w http.ResponseWriter, r *http.Request) {
 	}
 	// println(string(data))
 	w.Write(data)
-	}
 }