Question

What is the best approach for mocking out a static class in c#. For instance:

String appPath = System.Web.Hosting.HostingEnvironment.ApplicationPhysicalPath;

I want to mock this but will need to wrap it in a class with an interface, what is the best approach and does this approach work for all static methods?

Will this approach not make a lot of allmost pointless interfaces and classes?

Answer 1

What is the best approach for mocking out a static class in c#

The best approach is to hide those static calls behind abstractions. Those can be faked. For instance:

public interface IApplicationPhysicalPathProvider
{
    string ApplicationPhysicalPath { get; }
}

public class AspNetApplicationPhysicalPathProvider : IApplicationPhysicalPathProvider
{
    public string ApplicationPhysicalPath 
    {
        get { return HostingEnvironment.ApplicationPhysicalPath; }
    }
}

This advice holds for any mocking framework and even if you don’t use a mocking framework at all.