Keep your dart server running via an isolate

gistfile1.dart

import 'dart:io';
import 'dart:isolate';

void main(List<String> args) {
  var sPort = new ReceivePort();
  spawnIsolate(sPort.sendPort);

  sPort.listen((message) {
    if (message == null) {
      spawnIsolate(sPort.sendPort);
    } else {
      print(message);
    }
  });
}

spawnIsolate(SendPort sendPort) async {
  Isolate mainRunner = await Isolate.spawn(startServer, sendPort, paused:true);
  mainRunner.addOnExitListener(sendPort);
  mainRunner.addErrorListener(sendPort);
  mainRunner.resume(mainRunner.pauseCapability);
  return mainRunner;
}


startServer(SendPort sendPort) {
  server.startServer();
}