gistfile1.txt

public interface IMessageGateway
{
    // will throw exception if sending fails
    void SendSMS(SMS sms);
}


-------------------------------------------------


public class MessageDispatcher
{
    private static readonly Logger Log = LogManager.GetCurrentClassLogger();

    public IMessageGateway MessageGateway { get; private set; }

    public MessageDispatcher(IMessageGateway gateway)
    {
        MessageGateway = gateway;
    }

    public void SendSMS(SMS sms)
    {
        Log.Info("Sending SMS to message gateway: {0}", sms.ToJson());
        MessageGateway.SendSMS(sms);
    }
}

[13/02/2014 9:14:41 am]  so you have callbacks in NSubstitute where you can hide state like that
[13/02/2014 9:14:41 am]  http://nsubstitute.github.io/help/callbacks/
[13/02/2014 9:15:08 am]  but, how that mixes with throwing exceptions, i haven't tried
[13/02/2014 9:15:34 am]  ha, well look at that http://nsubstitute.github.io/help/throwing-exceptions/
[13/02/2014 9:15:47 am]  just throwing an exception inside the .Do seems to be all you need
[13/02/2014 9:16:51 am]  messageGateWay.WhenForAnyArgs(x => x.SendSms(null)).Do(x => if (++i < 2) { throw new Exception() });