Can not instantiate proxy...Could not find a parameterless constructor

I am trying to create a unit test using Moq which tests the [MongoDB.AspNet.Identity V2][1] provider. This line is giving me grief:

var appUser = new Mock<PreRegistrationMVC.Models.ApplicationUser>();
var userStore = new Mock<MongoDB.AspNet.Identity.UserStore<PreRegistrationMVC.Models.ApplicationUser>>();

It seems the userStore won't instantiate properly here is the error.

Castle.DynamicProxy.InvalidProxyConstructorArgumentsException was unhandled by user code
HResult=-2147024809
Message=Can not instantiate proxy of class: MongoDB.AspNet.Identity.UserStore`1[[MVC.Models.ApplicationUser, MVC, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].
Could not find a parameterless constructor.
Source=Moq
StackTrace:
at Castle.DynamicProxy.ProxyGenerator.CreateClassProxyInstance(Type proxyType, List`1 proxyArguments, Type classToProxy, Object[] constructorArguments)
at Castle.DynamicProxy.ProxyGenerator.CreateClassProxy(Type classToProxy, Type[] additionalInterfacesToProxy, ProxyGenerationOptions options, Object[] constructorArguments, IInterceptor[] interceptors)
at Moq.Proxy.CastleProxyFactory.CreateProxy(Type mockType, ICallInterceptor interceptor, Type[] interfaces, Object[] arguments)
at Moq.Mock`1.<InitializeInstance>b__2()
at Moq.PexProtector.Invoke(Action action)
at Moq.Mock`1.InitializeInstance()
at Moq.Mock`1.OnGetObject()
at Moq.Mock.GetObject()
at Moq.Mock.get_Object()
at Moq.Mock`1.get_Object()
at MVC_Tests.Identity.Accounts.AccountController_Test.TestSuccessfulRegister() in c:\Users\Tim\Documents\Visual Studio 2013\Projects\PreRegistrationApp\MVC_Tests\Identity\Accounts\AccountController_Test.cs:line 108
InnerException:


I am completely new to Moq so I am looking for:
What type of settings are needed for Moq to instantiate this? Is there something about the UserStore class that won't play well with Moq?

Thanks for reading.


[1]:

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MOQ is good for mocking interfaces, but does not work so well with concrete classes. So instead of mocking concrete class, ask for the inteface:

var userStore = new Mock<IUserStore<PreRegistrationMVC.Models.ApplicationUser>>();

Also `ApplicationUser` should be POCO, so no need to mock it, just create its instance without MOQ and use in tests.

I had this problem. I had written...

var x = new Mock<Concrete>();

... instead of ...

var x = new Mock<IConcrete>();

You can try referring Mock behavior,as shown below

Mock<testClass>(MockBehavior.Strict, new object[] {"Hello"});

Add an empty constructor to your `ApplicationUser` class.

I know this is a late response, but I was looking for an answer and couldn't find exactly what I needed, but when creating a mock, you can pass the parameters to your wanted constructor.

So for example if you have class like this:

public class Foo
{
private readonly Boo _boo;

public Foo(Boo boo)
{
_boo = boo;
}
}



You can mock it like this:

private readonly Mock<Foo> _foo = new Mock<Foo>(new Mock<Boo>().Object);