Am writing unit test for a multi-threading application, where I need to wait until a specific event triggered so that I know the asyn operation is done. E.g. When I call repository.add(something), I wait for event AfterChange before doing any assertion. So I write a util function to do that.

    public static void SyncAction(EventHandler event_, Action action_)
    {
      var signal = new object();
      EventHandler callback = null;
      callback = new EventHandler((s, e) =>
      {
        lock (signal)
        {
          Monitor.Pulse(signal);
        }

        event_ -= callback;
      });

      event_ += callback;

      lock (signal)
      {
        action_();
        Assert.IsTrue(Monitor.Wait(signal, 10000));
      }
    }

However, the compiler prevents from passing event out of the class. Is there a way to achieve that?