a.cs

public class MyController
{
    //in state testing ALL we can test is the state of the result.
    public ActionResult myAction()
    {
          //some controller stuff
          return result;
    }
 }   

b.cs

public class MyController
{
    //in state testing ALL we can test is the state of the result.
    public ActionResult myAction()
    {
          //some controller stuff
          return result;
    }
 }   

c.cs

public class MyService
{ 
     // i should be testing here too!
     public Bar Stuff(object foo)
     {
        //somecomplex stuff.

        return new Bar();
     }

}