Routemeister how to support request response

Currently Routemeister does not come with built in support for a request-response scenario, much because I haven't decided on how this should behave and there hasn't been a need for it yet. But this doesn't stop you from implementing support for it.

Routemeister is asynchronous, hence it relies on the handler to return a Task. Well luckily, Task<T> extends Task. We can use this to our advantage.

Lets take the shipped SequentialAsyncRouter and add one "small" method to it:

public async Task<TResult> RequestAsync<TResult>(object message)
{
    var messageType = message.GetType();
    var route = _messageRoutes.GetRoute(messageType);
    if (!route.Actions.Any())
        return default(TResult);

    if (route.Actions.Length > 1)
        throw new Exception("The route has more than one action...");

    var envelope = new MessageEnvelope(message, messageType);
    var action = route.Actions[0];
    var resultingTask = (Task<TResult>)action.Invoke(
        _messageHandlerCreator(action.HandlerType, envelope),
        envelope.Message);

    return await resultingTask.ConfigureAwait(false);
}

And there we go, you can now define your handler (remeber you are in control) to support responses:

public interface IMyRequestHandlerOf<in TRequest, TResponse>
{
    Task<TResponse> HandleAsync(TRequest request);
}

Actually, it works just as well without the response type, but semantics are good so I would define this second interface for defining handlers supporting request-response messaging.

Feel free to comment on if this should be put in Routemeister as is.

Happy routing!

//Daniel