Quantcast
Viewing latest article 10
Browse Latest Browse All 33

Unit Tests for ASP.NET MVC application that uses resources in code behind.

Image may be NSFW.
Clik here to view.
Download source files - here.

Some time ago I start to play with ASP.NET MVC. It is very well pattern and Microsoft made nice choose that implemented it for ASP.NET in my opinion.
I started a project that uses ASP.NET MVC. This project requests multilingual support. I use resources for this. It works well when I use resource's properties in the View's layer but when I call resource's properties from code behind. It's something likes to next:
public ActionResult Index()
{
ViewData["Message"] = CommonResource.WELCOME;
return View();
}
It works but I pay attention that this code breaks my Unit Tests. My Unit Tests looks like:
[TestMethod]
public void Index_Test()
{
//// Arrange
var controller = new HomeController();

// Act
var result = controller.Index();

// Assert
Assert.IsInstanceOfType(result, typeof(ViewResult));
}
It happens because I run my code in other project and my ResourceManager is not filled (it equals to null). How can I fix it? A first idea that came to mind is "extract interface".. but it is very annoying because resource's class is auto-generate and I should update this code after each updating of resources.. I made some research and found additional way for extracting resources - HttpContext contains GetGlobalResourceObject method! It is well way because I can set mock for HttpContext and for any its methods or properties.

Note:GetGlobalResourceObject returns object but I use only strings for localization. So I create linq method for HttpContext that returns string if it presents:
public static string GetGlobalResource(
this HttpContextBase httpContext
, string classKey, string resourceKey)
{
var result = httpContext.GetGlobalResourceObject
(classKey, resourceKey);
return null != result
? result.ToString() : string.Empty;
}
Pay attention, MissingManifestResourceException is possible in this code if you pass incorrect key/keys!

So I change pieces of code in Controller's classes in the next manner:
public ActionResult Index()
{
ViewData[CommonStrings.MESSAGE] = HttpContext
.GetGlobalResource(CommonStrings
.COMMON_RESOURCE, CommonStrings.WELCOME);
return View();
}
After it I should change my Unit Test's methods in next manner:
[TestMethod]
public void Index_Test()
{
//// Arrange
var httpContextMock = MockRepository
.GenerateMock<HttpContextBase>();
httpContextMock.Stub
(x => x.GetGlobalResource(
CommonStrings.COMMON_RESOURCE, CommonStrings.WELCOME))
.Return(CommonStrings.WELCOME);

var controller = new HomeController();
var context = new ControllerContext
(httpContextMock, new RouteData(), controller);
controller.ControllerContext = context;

// Act
var result = controller.Index();

// Assert
Assert.IsInstanceOfType(result, typeof(ViewResult));
ViewDataDictionary viewData = ((ViewResult)result).ViewData;
Assert.AreEqual(CommonStrings.WELCOME
, viewData[CommonStrings.MESSAGE]);
}
Moreover, you can see that I added additional checking related to localization.

Viewing latest article 10
Browse Latest Browse All 33

Trending Articles