ABTesting by using an ActionFilterAttribute

Question

We are thinking of doing some unit testing with MVC3. I thought a reasonable solution would be to mark actions to return "B" Views and to mark other actions so that result could be recorded.

Perhaps a controller would look like this:

[AB(ABModes.View)]
public ActionResult SignUp()
{
    return View();
}

[HttpPost]
public ActionResult SignUp(int id)
{
    return RedirectToAction("Confirmation");
    return View();
}

[AB(ABModes.Result)]
public ActionResult Confirmation()
{
    return View();
}

The SignUp would return an A or B View and the Confirmation would record which View was used.

The attribute would look something like this:

using System;
using System.Web.Mvc;

namespace ABTesting.lib
{
    public class ABAttribute : ActionFilterAttribute
    {
        private ABModes mode;
        private Abstract.IABChooser abChooser;
        private Abstract.IABLogMessenger abMessenger;

        public ABAttribute(ABModes mode) : this(mode, new Concrete.ABChooser(), null)
        {

        }

        public ABAttribute(ABModes mode, Abstract.IABChooser abChooser, Abstract.IABLogMessenger abMessenger)
        {
            this.mode = mode;
            this.abChooser = abChooser;
            this.abMessenger = abMessenger;
        }


        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            var result = filterContext.Result as ViewResultBase;
            var action = filterContext.Controller.ControllerContext.RouteData.Values["action"].ToString();
            var actionName = String.IsNullOrEmpty(result.ViewName) ? action : result.ViewName;
            if(mode == ABModes.View)
                result.ViewName = String.Format("{0}{1}", actionName, abChooser.UseB()? "_B" : String.Empty);
            else{
                var controller = filterContext.Controller.ControllerContext.RouteData.Values["controller"].ToString();
                if (abMessenger != null)
                    abMessenger.Write(new Entities.ABLogMessage
                                          {
                                              DateCreated = DateTime.Now,
                                              ControllerName = controller,
                                              ActionName = actionName,
                                              IsB = abChooser.UseB()
                                          });
            }
            base.OnActionExecuted(filterContext);
        }
    }
}

and

public interface IABChooser
{
    bool UseB();
}

and

public interface IABLogMessenger
{
    void Write(ABLogMessage message);
}

Does this seem like a reasonable way of accomplishing this with minimal code changes?

Answer 1

This does seem like a reasonable solution. I know this because I have used this same concept to develop an A/B testing framework (http://www.nuget.org/packages/AbTestMaster). It's freely available on nuget and is open source as well.

That might make your life slightly simpler.