import 'dart:html';

void main() {
  wsAPI()
    .then((_) => print('Great success!'))
    .catchError((_) => print('Miserable failure'));
}
  
Future<void> wsAPI() async {
  try {
    final socket = await wsConnect('wss://127.0.0.1:7654');
    print('${socket.readyState}');
  } catch (e) {print(e);}  
}

Future<WebSocket> wsConnect(String url) async {
  final socket = WebSocket(url);
  socket.onError.listen((_) => throw Exception('connection error'));
  socket.onClose.listen((_) => throw Exception('connection close'));
  return socket;
}