To show how you could test a NHibernate session.Query<T> on a controller

Action result

   [NHibernateActionFilter]
   public class MemberController

      private readonly IDbService db;

      public MemberController(IDbService db)
      {
         this.db = db;
      }


    public ActionResult CompanyPage(int id)
      {
         var model = new CompanyPageViewModel
            {
               CompanyPage = db.Query<BobMemberCompanyPage>().FirstOrDefault(w => w.Id == id)
            };

         return View("CompanyPage", model);
      }
}

DbService

    public class DbService : IDbService
    {
        [Dependency]
        public ISessionFactory SessionFactory { get; set; }

        [Dependency]
        public ISession Session
        {
            get { return SessionFactory.GetCurrentSession(); }
        }

        public IQueryable<T> Query<T>() where T : class
        {
            return Session.Query<T>();
        }
  }

FakeDbService

   public class FakeDbService : IDbService
   {
      public FakeDbService()
      {
      }

      public ISessionFactory SessionFactory { get; set; }
      public ISession Session
      {
         get
         {
            var mock = new Mock<ISession>();
            mock.Setup(w => w.Save(It.IsAny<object>()));
            return mock.Object;
         }
      }

      public IQueryable<T> Query<T>() where T : class
      {
         return Sets[typeof(T)] as IQueryable<T>;
      }

      public void AddSet<T>(IQueryable<T> objects)
      {
         Sets.Add(typeof(T), objects);
      }
   }
  }

global

   public class MvcApplication : HttpApplication
   {

      public static ISessionFactory SessionFactory { get; set; }

     ....

     
      protected void Application_Start()
      {
         SessionFactory = SetUpNhibernate();
         Bootstrapper.Initialise();  //makes call to setup unity...
         ....
      }

}  

iDbService

   public interface IDbService
   {
      ISessionFactory SessionFactory { get; set; }
      ISession Session { get; }
      IQueryable<T> Query<T>() where T : class;
   }

Test

      [TestMethod]
      public void test_company_view_for_an_unkown_user()
      {
         var db = new FakeDbService();
         db.AddSet(TestData.BobMemberCompanyPages);
         var controller = new MemberController(db);

         var result = controller.CompanyPage(12) as ViewResult;

         const string expected = "CompanyPage";
         Assert.IsNotNull(result, "Should have returned a ActionResult");
         Assert.AreEqual(expected, result.ViewName);
      }

Testdata

public class TestData
{
  public static IQueryable<BobMemberCompanyPage> BobMemberCompanyPages
      {
         get
         {
            return
               new List<BobMemberCompanyPage> { 
                   new BobMemberCompanyPage { Id = 12, CompanyName = "company", Show = true}
               }.AsQueryable();
         }
      }
}

unity setup

            container.RegisterType<IDbService, DbService>();
            container.RegisterType<ISession>();
            //Session Factory
            container.RegisterInstance<ISessionFactory>(MvcApplication.SessionFactory);