How to access JsonResult data when testing in ASP.NET MVC

Question

I have this code in C# mvc Controller:

[HttpPost]
    public ActionResult Delete(string runId)
    {
        if (runId == "" || runId == null)
        {
            return this.Json(new { error = "Null or empty params" });
        }
        try
        {
            int userId = (int)Session["UserId"];
            int run = Convert.ToInt32(runId);

            CloudMgr cloud = new CloudMgr(Session);
            cloud.DeleteRun(userId, run);

            return this.Json(new { success = true });
        }
        catch (Exception ex)
        {
            return this.Json(new { error = ex.ToString() });
        }
    }

How I can access my Json "error" field in a ControllerTest to check if it is null or not?

[TestMethod]
    public void DeleteWrongParam()
    {
        WhatIfController controller = new WhatIfController();
        controller.ControllerContext = 
        TestUtils.CreateMockSessionControllerContext().Object as ControllerContext;

        JsonResult result = controller.DeleteWhatIf(null) as JsonResult;

Assert.IsNotNull(result.Data.error); is what I would like to do. Any Ideas? Thanks.

Answer 1

You can use like this - the result will be the expected object definition. So in case of success, your success flag will be TRUE otherwise false and if false then you should expect that the error property will be updated with the error message.

        JsonResult jsonResult = oemController.List() as JsonResult;
        JavaScriptSerializer serializer = new JavaScriptSerializer();
        Result result = serializer.Deserialize<Result>(serializer.Serialize(jsonResult.Data));

        public class Result 
        {
            public bool success ;
            public string error;
        }

Answer 2

JavaScriptSerializer is good for string and static type. Here you created anonymous type as Json(new { success = true }). This case, you had better used dynamic type.

JsonResult result = controller.DeleteWhatIf(null) as JsonResult;
dynamic dresult = result.Data;
Assert.IsTrue(dresult.succes);

You need to import Microsoft.CSharp dll to test project.

If test and your controller are in different assemblies, you need to make the test assembly a "friend" assembly of the controller assembly, like this:

[assembly: InternalsVisibleTo("testproject assembly name")]