testing the controller in asp.net mvc

Question

Hi,

I would like to test the validation of submitted DTO. This is the bare bone of a controller create action:

[AcceptVerbs(HttpVerbs.Post)]
        public RedirectToRouteResult Create(SomeDTO SomeDTO)
        {
            SomeObject SomeObject = null;

            try
            {
SomeObject = this.RepositoryService.getSomeObjectRepository().Create(SomeDTO, this.RepositoryService);
            }
            catch (BrokenRulesException ex)
            {
                ex.AddModelStateErrors(ModelState, "Model");
            }
            catch (Exception e)
            {
                ModelState.AddModelError("Exception", e.Message);
            }

            TempData["ViewData"] = ViewData;
            TempData["SomeDTO "] = SomeDTO;

            return ModelState.IsValid ? RedirectToAction("SomeObjectDetail", new { Id = SomeObject.Id }) : RedirectToAction("Form");
        }

The mechanics , although not relevant, is as follows: I have a strongly typed view = form which submits a dto to this action which either returns the form or the details page of the created object.

I would like to unit test whether the Model contains certain key/errorMessage combinations given some invalid dto. Did someone do similar stuff? Any pointers would be very much appreciated.

Thanks.

Best wishes,

Christian

Answer 1

In your case, I don't think you really want to test the model state. Rather, you should simply use the test set up to induce a correct/incorrect model state, then test that the appropriate result is returned under the conditions. You can use separate tests to validate the various conditions under which the model is valid/invalid, though, if you use DataAnnotations, I don't see much point in testing that they and the model binding infrastructure work correctly. Presumably Microsoft has already done this.

Original, based on the (faulty) assumption that a ViewResult was being returned

I think it should be something like this.

[TestMethod]
public void TestCreate()
{
     // set up

    var result = Create( invalidDTO ) as ViewResult;

    var modelState = result.ViewData.ModelState;

    Assert.IsFalse( modelState.IsValid );

    var errors = modelState.Errors;

    Assert.AreEqual( 1, errors.Count );
    Assert.AreEqual( errors[0].ErrorMessage, "some error message" );
}