Question

In my unit tests, I use things like AssemblyInitialize, ClassInitialize and TestInitialize to configure my tests. In AssemblyInitialize I initialize some singleton factories for creating services, a unit of work and repositories (all trough Unity/Dependency Injection). In my TestInitialize I clear the state they have to make sure each test can run independently.

Trough Stackoverflow I came around the following articles: Writing Testable Code and How to Think About the “new” Operator with Respect to Unit Testing. I have to say they changed how I think about some code I’ve written but my mind is still buzzing.

For example, take the following code:

public class MyPresenter : BasePresenter<IMyView>
{
    public MyPresenter(IMyView view) 
        : base(view)
    {
    }

    public void PrepareView()
    {
        using (IMyService service = ServiceFactory.Instance.CreateService<IMyService>())
        {
            View.Data = service.GetData();
        }
    }
}

Which is used in an aspx page like this:

Presenter = new MyPresenter(this);
if (!IsPostback)
{
    presenter.PrepareView();
}

How should I change this type of kind with the previous articles in mind? Should I pass a service instance to the PrepareView method? But then my ASPX page has to know about services and factories and stuff and dispose of the service after it’s used.

What should I do with my Singleton factory? Make it a property of the class and inject it trough Unity?

Answer 1

I found this kind of resolving dependencies inelegant, Take a look at the way Ninject wire the dependencies or inject them.

You can see the difference, Service Locator is an antipattern, reading this blog also makes more clear the essential purpose and practices for dependency injection in .NET