Mocking Task<IEnumerable<T>> with NSubstitute - asp.net-mvc

I'm having issues trying to get NSubstitute to return an IEnumerable interface from a Task.
The factory I'm mocking:
public interface IWebApiFactory<T> : IDisposable
{
<T> GetOne(int id);
Task<IEnumerable<T>> GetAll();
Task<IEnumerable<T>> GetMany();
void SetAuth(string token);
}
The test method:
[TestMethod]
public async Task TestMutlipleUsersAsViewResult()
{
var employees = new List<EmployeeDTO>()
{
new EmployeeDTO(),
new EmployeeDTO()
};
// Arrange
var factory = Substitute.For<IWebApiFactory<EmployeeDTO>>();
factory.GetMany().Returns(Task.FromResult(employees));
}
The error I am getting is:
cannot convert from 'System.Threading.Tasks.Task> to System.Func>>
Is this an issue with me passing a list, as a posed to IEnumerable even though List is IEnumerable?
Edit:
These are the functions within NSubstitute
public static ConfiguredCall Returns<T>(this T value, Func<CallInfo, T> returnThis, params Func<CallInfo, T>[] returnThese);
public static ConfiguredCall Returns<T>(this T value, T returnThis, params T[] returnThese);

None of the overloads is a good match for the value you passed. The second signature, public static ConfiguredCall Returns<T>(this T value, T returnThis, params T[] returnThese); expect a value of the same type as the function's return type so it isn't the best match.
The simplest way to overcome this is to change the declaration of employees to IEnumerable<EmployeeDTO> :
IEnumerable<EmployeeDTO> employees = new List<EmployeeDTO>()
{
new EmployeeDTO(),
new EmployeeDTO()
};

Related

MVC optional body parameter

I am trying to wire up a webhook from a 3rd party system.
When creating the subscription it hits the URL i provide and requires a validated token returned to create the hook.
When the event is triggered the hook posts to the same URL i provided with data in the body.
How can I get a Core 2.1 MVC controller/routing to see these as either two different methods on the controller or a method signature where the complex object is optional?
Either two POST methods (this creates ambiguity exception)
public async Task<IActionResult> Index(){}
public async Task<IActionResult> Index([FromBody] ComplexObject co){}
or complexObject is optional (if not it throws a Executing ObjectResult, writing value of type '"Microsoft.AspNetCore.Mvc.SerializableError" on the subscription creation step.)
public async Task<IActionResult> Index([FromBody] ComplexObject co){}
Another way around this :
public class AllowBindToNullAttribute : ModelBinderAttribute
{
public AllowBindToNullAttribute()
: base(typeof(AllowBindToNullBinder))
{
}
public class AllowBindToNullBinder : IModelBinder
{
public async Task BindModelAsync(ModelBindingContext bindingContext)
{
var stream = bindingContext.HttpContext.Request.Body;
string body;
using (var reader = new StreamReader(stream))
{
body = await reader.ReadToEndAsync();
}
var instance = JsonConvert.DeserializeObject(body, bindingContext.ModelType);
bindingContext.Result = ModelBindingResult.Success(instance);
}
}
}
You'd use it like this:
public async Task<IActionResult> Index(
[FromBody] [AllowBindToNull] ComplexObject co = null){}
I used the empty parameter method signature and checked the body for data. Not ideal.

Autofac Automocking in ASP.NET MVC

So I'm trying to use Autofac Automocking in ASP.NET MVC 5, but for some reason I can't get it to work.
Here's the test so far:
using (var mock = AutoMock.GetLoose())
{
const string mainUserID = "MainUserID";
const string otherUserID = "OtherUserID";
ApplicationUser user = new ApplicationUser()
{
Id = mainUserID,
UserName = "TestUser"
};
var dataProvider = mock.Mock<IDataProtectionProvider>();
dataProvider.DefaultValue = DefaultValue.Mock;
var userManagerMock = mock.Mock<ApplicationUserManager>();
}
The test fails when mocking the ApplicationUserManager. The error is this:
Result StackTrace:
at Autofac.Extras.Moq.AutoMock.Mock[T](Parameter[] parameters)
at AwenterWeb_NUnit.AccountControllerTest.<Deactivate_User>d__0.MoveNext() in C:\Users\Fabis\Documents\Docs\Kvalifikācijas darbs 2015\AwenterWeb\AwenterWeb-NUnit\AccountControllerTest.cs:line 51
at NUnit.Framework.AsyncInvocationRegion.AsyncTaskInvocationRegion.WaitForPendingOperationsToComplete(Object invocationResult)
at NUnit.Core.NUnitAsyncTestMethod.RunTestMethod()
Result Message: System.InvalidCastException : Unable to cast object of type 'AwenterWeb.ApplicationUserManager' to type 'Moq.IMocked`1[AwenterWeb.ApplicationUserManager]'.
The same thing happens when trying to automock the ApplicationDbContext and it has a very simple constructor, so there shouldn't even be any issues with it.
I'm new to Mocking - what should I do in this scenario?
Edit: Also kind of an unrelated question, maybe you guys know - I've noticed that when creating a Moq for a DbSet using a list created previously in the test, I have to do this:
var dbSetMock = new Mock<IDbSet<DbEntity>>();
dbSetMock.Setup(m => m.Provider).Returns(data.Provider);
dbSetMock.Setup(m => m.Expression).Returns(data.Expression);
dbSetMock.Setup(m => m.ElementType).Returns(data.ElementType);
dbSetMock.Setup(m => m.GetEnumerator()).Returns(data.GetEnumerator());
It seems really unintuitive. Is there a way to just tell the mock to take the list? So something like:
dbSetMock.Setup(m => m).Returns(data);
Or any other way to create a DbSet Moq from an existing list quickly without having to write those 4 extra lines?
If you look at ligne 73 of MoqRegistrationHandler.cs you can see that only interface is moqable using Autofac.Extras.Moq
var typedService = service as TypedService;
if (typedService == null ||
!typedService.ServiceType.IsInterface ||
typedService.ServiceType.IsGenericType && typedService.ServiceType.GetGenericTypeDefinition() == typeof(IEnumerable<>) ||
typedService.ServiceType.IsArray ||
typeof(IStartable).IsAssignableFrom(typedService.ServiceType))
return Enumerable.Empty<IComponentRegistration>();
var rb = RegistrationBuilder.ForDelegate((c, p) => CreateMock(c, typedService))
.As(service)
.InstancePerLifetimeScope();
You can change the code but it may be quite difficult to make it works with non parameter less dependency.
Can your dependencies be changed to use an interface instead of a concrete class ? if it is not possible and/or if it doesn't make sense, you can use the MockRepository to create your non parameter-less component and then inject it on the AutoMock class.
class Program
{
static void Main(string[] args)
{
using (var mock = AutoMock.GetLoose())
{
/// configure your non interface component with constructor parameters
/// if foo need more complex parameters you can get them
/// using mock.Mock<T>().Object
var fooMock = mock.MockRepository.Create<Foo>((String)null);
fooMock.SetupGet(f => f.Value).Returns("test");
// insert your instance into the container
mock.Provide<Foo>(fooMock.Object);
var bar = mock.Create<Bar>();
Console.WriteLine(bar.GetValue());
}
}
}
public class Foo
{
public Foo(String value)
{
this._value = value;
}
private readonly String _value;
public virtual String Value
{
get
{
return this._value;
}
}
}
public interface IBar
{
String GetValue();
}
public class Bar : IBar
{
public Bar(Foo foo)
{
this._foo = foo;
}
private readonly Foo _foo;
public String GetValue()
{
return this._foo.Value;
}
}
It is not a perfect solution but without big refactoring of the Autofac.Extras.Moq project I can't see any simpler way to do it.

mvvmcross showviewmodel byte[] as param

I work with iOS throw Xamarin. I want's send byte[] from one viewModel to another using showviewmodel.
I invoke this Command:
private MvxCommand _editUser;
public System.Windows.Input.ICommand EditUser
{
get{
return new MvxCommand
(() => ShowViewModel<UserViewModel> (new {array = new byte[3]}));
}
}
and wait my byte[] as param in Init method on another viewModel(UserViewModel):
public void Init(byte[] array)
{
}
Constructor works good, but then does not reach the the Init method;
It throws an exception:
Failed to construct and initialize ViewModel for type AccountApp.Core.iOS.UserViewModel from locator MvxDefaultViewModelLocator - check MvxTrace for more information.
Any ideas?
Thanks.
Only strings, ints, doubles and bools are allowed in this constructor parameter passing at present. You would need to serialize this byte[] array to a string and then reconstruct it in the constructor of the view model you are navigating to.

Access the error message in ModelState error dictionary in ASP.net MVC unit test

I have added a key-value pair in the action result like this:
[HttpPost, Authorize]
public ActionResult ListFacilities(int countryid)
{
...
ModelState.AddModelError("Error","No facilities reported in this country!");
...
}
I have some cumbersome codes like these in a unit test to :
public void ShowFailforFacilities()
{
//bogus data
var facilities = controller.ListFacilities(1) as PartialViewResult;
Assert.AreSame("No facilities reported in this country!",
facilities.ViewData.ModelState["Error"].Errors.FirstOrDefault().ErrorMessage);
}
Of course, it works whenever I have only one error.
I don't like facilities.ViewData.ModelState["Error"].Errors.FirstOrDefault().ErrorMessage.
Is there an easier way for me to fetch the value from that dictionary?
Your FirstOrDefault isn't needed, because you'll get a NullReferenceException when accessing ErrorMessage. You can just use First().
Either way, I couldn't find any built-in solution. What I've done instead is create an extension method:
public static class ExtMethod
{
public static string GetErrorMessageForKey(this ModelStateDictionary dictionary, string key)
{
return dictionary[key].Errors.First().ErrorMessage;
}
}
Which works like this:
ModelState.GetErrorMessageForKey("error");
If you need better exception handling, or support for multiple errors, its easy to extend...
If you want this to be shorter you can create an extension method for the ViewData...
public static class ExtMethod
{
public static string GetModelStateError(this ViewDataDictionary viewData, string key)
{
return viewData.ModelState[key].Errors.First().ErrorMessage;
}
}
and usage:
ViewData.GetModelStateError("error");
Have you tried this?
// Note: In this example, "Error" is the name of your model property.
facilities.ViewData.ModelState["Error"].Value
facilities.ViewData.ModelState["Error"].Error

Selecting Instances of an Interface Based On Specific Value

I'll start here with a little bit of background. We have an ASP.Net MVC web application that sits upon a structure roughly based upon the Onion Architecture concept. Therefore, we have the following (simplified) vertical structure:
ASP.Net MVC controller layer
Application service layer
Business Service layer
NOTE: The above is simplified because it doesn't deal with the views, repositories, domain objects, etc which aren't relevant to this question.
For a horizontal structure, we have some major areas defined by what we call "Item Types" (for the sake of simplicity, this question will deal with two sample item types: "ItemTypeA", "ItemTypeB", etc).
We have a business service interface which has a separate implementation per item type:
public interface ISampleBusinessService
{
string SampleMethod(string arg);
}
public class ItemTypeASampleBusinessService : ISampleBusinessService
{
public string SampleMethod(string arg)
{
return "Item Type A: " + arg;
}
}
public class ItemTypeBSampleBusinessService : ISampleBusinessService
{
public string SampleMethod(string arg)
{
return "Item Type B: " + arg;
}
}
Sitting above that is an application service that uses the business service:
public interface ISampleAppService
{
string SampleMethod(string arg);
}
public class SampleAppService
{
private readonly ISampleBusinessService service;
public SampleAppService(ISampleBusinessService service)
{
this.service = service
}
public string SampleMethod(string arg)
{
return service.SampleMethod(arg);
}
}
And sitting above that is our controller which uses the application service:
public class SampleController : Controller
{
private ISampelAppService service
public SampleController(ISampleAppService service)
{
this.service = service;
}
public PartialViewResult SampleAction(string arg)
{
return PartialView( service.SampleMethod(arg) );
}
}
Note that the controller, application service interface and implementation, and business service interface are all generic - they don't care about which item type is being used. However, the business service implementations are specific to the item type. We know which item type we're dealing with at the time we call the action method on the controller (via RenderAction in the views) but we aren't sure what the best way to determine which business service implementation to use. There are a few options we've considered:
Base class the controller and create item type-specific controller inheritors, then something similar with the app services. This feels like a weak solution - we would end up writing a few classes that add nothing in terms of functionality except to work out which item type we're dealing with.
Pass a flag down to the service layer and create the service implementation in a factory (i.e. a SampleBusinessServiceFactory which takes an "itemType" argument in its CreateInstance method). The problem with this is that we're passing a variable down several layers just so that we can decide upon an implementation. We have used this approach so far.
Generics - we haven't really thought this one through but it seems that there would be some difficulties with this as well (how would you call an Action method with generics from an ActionResult call in the view?). It would be similar, in a sense to passing a flag down, but would be based upon strongly typing object/services instead of using enums/magic strings.
What approach would be best suited to solving this problem? New options would be welcomed.
Any help provided will be much appreciated.
Cheers,
Zac
This smells like Big Design Up Front ( http://en.wikipedia.org/wiki/Big_Design_Up_Front )
However its very possible to invoke both controllers and action methods generically:
In asp.net mvc is it possible to make a generic controller?
Some info about invoking actions with generic action results ( which result in the same effect ).
http://www.lostechies.com/blogs/jimmy_bogard/archive/2009/12/12/enabling-ioc-in-asp-net-actionresults-or-a-better-actionresult.aspx
I am a big fan of this approach and learning about these techniques is helpful to anybody who wants to keep their controllers extraordinarily slim.
Comment Answer:
You don't really need to call the generic action method, you just need a way to pass the generic parameter to your controller. The basic flow is to include your modelType as a route parameter. You could easily call generic render actions with the correct RouteValueDictionary. Here is some sample code from an older project of mine:
Start of my generic controller:
public GenericController()
{
TypeTranslator.Configure("Brainnom.Web.Model", "Brainnom.Web");
}
[UrlRoute(Path="admin/{modelType}/add", Order=9000)]
public virtual ActionResult Add()
{
return View( new MODEL() );
}
[HttpPost]
[UrlRoute(Path = "admin/{modelType}/add", Order = 9000)]
public virtual ActionResult Add( MODEL model, string modelType)
{
if (!ModelState.IsValid)
return View(model);
var postedModel = new MODEL();
UpdateModel(postedModel);
using (var session = new MongoSession())
{
session.Add(postedModel);
}
return RedirectToRoute("Browse", new { modelType });
}
and my GenericControllerFactory ( which I do need to refactor someday )
using System;
using System.Web.Mvc;
using System.Web.Routing;
namespace Brainnom.Web.Controllers
{
public class GenericControllerFactory : DefaultControllerFactory
{
protected override Type GetControllerType(System.Web.Routing.RequestContext requestContext, string controllerName)
{
//the generic type parameter doesn't matter here
if (controllerName.EndsWith("Co"))//assuming we don't have any other generic controllers here
return typeof(GenericController<>);
return base.GetControllerType(requestContext, controllerName);
}
protected override IController GetControllerInstance(System.Web.Routing.RequestContext requestContext, Type controllerType)
{
//are we asking for the generic controller?
if (requestContext.RouteData.Values.ContainsKey("modelType"))
{
string typeName = requestContext.RouteData.Values["modelType"].ToString();
//magic time
return GetGenericControllerInstance(typeName, requestContext);
}
if (!typeof(IController).IsAssignableFrom(controllerType))
throw new ArgumentException(string.Format("Type requested is not a controller: {0}",controllerType.Name),"controllerType");
return base.GetControllerInstance(requestContext, controllerType);
}
/// <summary>
/// Returns the a generic IController tied to the typeName requested.
/// Since we only have a single generic controller the type is hardcoded for now
/// </summary>
/// <param name="typeName"></param>
/// <returns></returns>
private IController GetGenericControllerInstance(string typeName, RequestContext requestContext)
{
var actionName = requestContext.RouteData.Values["action"];
//try and resolve a custom view model
Type actionModelType = Type.GetType("Brainnom.Web.Models." + typeName + actionName + "ViewModel, Brainnom.Web", false, true) ??
Type.GetType("Brainnom.Web.Models." + typeName + ",Brainnom.Web", false, true);
Type controllerType = typeof(GenericController<>).MakeGenericType(actionModelType);
var controllerBase = Activator.CreateInstance(controllerType, new object[0] {}) as IController;
return controllerBase;
}
}
}

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