I am a developer, I believe in unit testing and I write a lot of them. But it was not always the case, mostly because I was working on a highly coupled code base. Whenever I wanted to test a single functionality I had to set up a lot of things (database, configuration files, …) to do so even if this functionality was not linked to these dependencies. It was spaghetti code into a big ball of mud.

Then I discovered the Dependency Injection (DI) pattern and it changed the way I designed my code and it made testing much easier. The DI purpose is to reduce coupling between software components in order to improve maintainability and testability. I created the following piece of code to demonstrate the principle :

publicclass User
{publicstring Name {get;set;}publicstring Email {get;set;}