Task based workflow with NServiceBus and SignalR

Over the last six months our team has been working on breaking our system down into a whole lot of distinct, reusable components. Most of the work is completely automated, but there is always the case where we need some human input.

For each of these scenarios we've created very specific task based UI's, so we can taylor the screens to the exact need of the task. This has meant that we've been a lot more focused on solving a real business problem rather than just trying to jam as much information on the screen at once.

Up to this point, each task has been very distinct from the others, without too much consideration of the workflow that would really take place. There are a couple of options for how the tasks could be completed:

• Task centric users who complete just one type of task, and who don't particularly worry about the work flowing from their action
• Customer centric users who might need to call the customer to get some extra details, and are very interested in the way the rest of the work flows, as they want to be able to get all the information required to complete the whole transaction while on the phone. 

Our system currently supports task centric users, but we need a solution to customer centric solutions. For that, I had seen and heard a bit about SignalR:

Async signaling library for .NET to help build real-time, multi-user interactive web applications.

Along with listening to Hanselminutes, one of the posts that got me started was push notifications with nservicebus and signalr, which was right up my alley as we're using NServiceBus as our underlying infrastructure for messaging. The only difference in our project was using MVC3 for the web app, so I avoided the EventStream and created a class implementing SignalR's Hub - which was super easy.

I got a bit confused about how to get the Clients who are connected to my implementation of the Hub, but this stackoverflow answer from David Fowler helped me get the clients, so I could start notifying away!

Within a day I had a working notification system working! It definitely requires more refinement to make it more useful to our users, such as only notifying some people of the changes (trying to identify who 'owns' a transaction and wants to see further tasks) and some UI design to make things a bit friendlier, but it's definitely been really fund and easy to work with.

If you're working with task based UI's how do you create customer centric workflow?

Asynchronous Testing Woes

Over the last six months I've been having fun working with NServiceBus producing our new app at work. It's been great splitting our system up into functional bits (that we can hopefully reuse). Our current requirements mean we have one big saga (long running process) that uses a whole lot of handlers to get the job done.

This is awesome, as we've been able to attach a problem by talking about what the solution should be, splitting up into pairs and work on our own bit of the solution, then get back together and figure out our next bit of work, just having to define our messaging requirements collaboratively before we start.

We've also invested in writing specification tests with SpecFlow - taking a business scenario and making sure that our system can handle it from end to end. While this has been fun to learn, it's been hard work to get working due to the async nature of our system. What we've ended up doing is firing off the spec and then waiting 10 seconds until we check our auditing system to see if the saga has completed. This works fine for most of the tests, but there are often one or two specs that fail, but when you check the audits, everything has worked properly.

It would be awesome in this case to have a spec subscribe to the auditing events (currently there isn't an event published saying a saga has completed, but commands are sent to the auditor) - in that case the test could just wait until the publish, but it would also need a timeout (for when the saga actually fails).

This brings me to one problem that I've had with my specflow tests - the amount of time they take to run. These aren't like unit tests that we run all the time and only take a few seconds, the suit of tests takes minutes to run, so I'm looking to see if there are any solutions to run them in parallel. At the moment we use the NUnit library to implement the tests, but I have seen that MbUnit has a parallel library which looks interesting.

How do you do integration tests? Do you even do them?