Pairing Tour: Day 3

Today I continued my pairing tour with Steven Degutis. I worked with him on a client's Rails app. However, this particular client has a very interesting setup with their application. They have brought service oriented architecture to the Rails world. Their application is actually multiple applications communicating with each other via HTTP requests. This may sound pretty messy, but they have managed to isolate the service calls into gems, which are managed and tested on their own. So each service (i.e. Rails app) has its own gem that wraps all the HTTP calls so that the user of the service is none the wiser. This really doesn't seem to bad. However, in practice it hasn't turned out so well. The have experienced some pain in adding features to the services. Adding a feature to a services means updating all of it's clients as well. This is not an inherent aspect of SOA, but it is a sign that they have broken the Common Closure Principle. They are starting to see that many of these separate modules all change together, which means that they should be kept together in the same package. Unfortunately, there is no simple answer to solving this problem. Bring the clients and services together into the same package is going be very difficult, especially since both clients and services are Rails apps. So, I definitely learned a lesson about the CCP today. On another note, pairing with Steven was a fun time. He is very discipled. He sticks to his principles well. And, he is very fast. I don't think I have ever seen anyone type and maneuver around Vim like he does. I definitely leaned a lot by pairing with him. I'm not pairing with a Craftsman tomorrow, because it's Friday, so I get to work on some Open Source stuff. I've been interested in Jasmine, the BDD framework for Javascript lately, so I'm planning to work on that.