One of the “sexy” buzz words, or more accurately “buzz phrases” that is being bandied around with increased frequency is “unit testing”. Put simply unit testing is the ability to implement specific tests of small “units” of an application (often down at the individual method level) and then automate those tests in a predictably repeatable way. The theory goes that if you are able to automate the testing of all of the individual building blocks of your application, ensuring that each of those components behaves as expected under various circumstances, testing what happens when you use those components as expected, and also when you use them in ways that they are not supposed to be used, then you stand a much better change of the application as a whole behaving as expected.

There are several popular unit testing frameworks available and in common use today, many of which integrate directly with common development tools such as Microsoft Visual Studio. In fact some versions of Visual Studio have an excellent unit testing framework build in; it’s called the Microsoft Unit Test Framework for Managed Code and it is included in the Visual Studio Premium and Ultimate editions. I am delighted to be able to tell you that in Synergy .NET version 10.1 we have added support for unit testing Synergy applications with that framework.

I’ve always been of the opinion that unit testing is a good idea, but it was never really something that I had ever set out to actually do. But that all changed in December, when I found that I had a few spare days on my hands. I decided to give it a try.

As many of you know I develop the CodeGen tool that is used by my team, as well as by an increasing number of customers. I decided to set about writing some unit tests for some areas of the code generator.

I was surprised by how easy it was to do, and by how quickly I was able to start to see some tangible results from the relatively minimal effort; I probably spent around two days developing around 700 individual unit tests for various parts of the CodeGen environment.

Now bear in mind that when I started this effort I wasn’t aware of any bugs. I wasn’t naive enough to think that my “baby” was bug free, but I was pretty sure there weren’t many bugs in the code, I pretty much thought that everything was “hunky dory”. Boy was I in for a surprise!

By developing these SIMPLE tests … call this routine, pass these parameters, expect to get this result type of stuff … I was able to identify (and fix) over 20 bugs! Now to be fair most of these bugs were in pretty remote areas of the code, in places that perhaps rarely get executed. After all there are lots of people using CodeGen every day … but a bug is a bug … the app would have fallen over for someone, somewhere, sometime, eventually. We all have those kind of bugs … right?

Anyway, suffice it to say that I’m now a unit testing convert. So much so in fact that I think that the next time I get to develop a new application I’m pretty sure that the first code that I’ll write after the specs are agreed will be the unit tests … BEFORE the actual application code is written!

Unit testing is a pretty big subject, and I’m really just scratching the surface at this point, so I’m not going to go into more detail just yet. So for now I’m just throwing this information out there as a little “teaser” … I’ll be talking more about unit testing with Synergy .NET at the DevPartner conferences a little later in the year, and I’ll certainly write some more in-depth articles on the subject for the BLOG also.