At some point, we all have to write some small apps. I’m talking about things like…
- Some small utility or diagnostic app
- Something to help with your deployment process
- Other small applications or websites (i.e. something that takes a month or less)
In these cases, we often throw good software design principles out the window. We say that we don’t need to write unit tests, we don’t need dependency injection, we can put data access code in our code-behinds, and things like that. Since it’s a small app, we think we can get away with it.
Just because your app didn’t take you long to write doesn’t mean that you get off easy. The consequences of your decisions just aren’t as severe, but that doesn’t mean that the pain is gone!
How many times have you written some small utility to help with something and then your boss sees it and really likes it, and then he asks you to add more functionality to it. Eventually you’ve spent a couple months on the app. If you cheated at the beginning, that code is going to hard to change and it’s going to start becoming more of a pain.
Maybe you’re writing a console app to help with your deployment process. Now this code better work, because if it doesn’t, your app might not deploy correctly. This is very important code! Doesn’t code this important warrant some extra attention (i.e. tests)?
Look, I’m not saying that every little app has to be this big, blown-out, enterprise application. I’m just saying that you should be careful when you cheat, because you don’t want that to come back to haunt you.
Many times you can take simple steps to make things easier to change. Take dependency injection, for example. It is really easy to set up an IoC container like StructureMap, it doesn’t overly complicate your code, and you don’t have to write tons of extra code to use it. But if you want to write tests for you code, dependency injection will make it a lot easier. You’re just putting code in better places.
Again, there are times to use dependency injection and there are times where it’s superfluous. There are times when unit testing is essential and times when you can get away with it (personally I always like writing tests if I can, that way I know my code works). But you need to be careful. Software is software, and many of the same development principles that apply to big apps still apply to small apps.