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Override AutoFixture ICustomization registrations using moq / automoq and xunit

I have the following setup:
A calendar controller that calls a calendar service that calls a calendar client wrapper that calls the client. Controller -> Service -> ClientWrapper -> Client.
I am making an integration test that mocks the lowest tier (the client) and calls the controller to see if the client was called correctly.
My CalendarControllerBuilder:
internal class CalendarControllerBuilder
{
public CalendarControllerBuilder()
{
CalendarClientMock = new Mock<ICalendarServiceClient>(MockBehavior.Strict);
}
public Mock<ICalendarServiceClient> CalendarClientMock { get; set; }
public CalendarControllerBuilder With(Mock<ICalendarServiceClient> calendarClientWrapperMock)
{
CalendarClientMock = calendarClientWrapperMock;
return this;
}
public CalendarController Create()
{
var calendarClientWrapperMock = new CalendarClientWrapper(CalendarClientMock.Object);
var calenderService = new CalendarService(calendarClientWrapperMock);
return new CalendarController(calenderService);
}
}
Test setup with customization registration:
internal class CalenderControllerCustomization : ICustomization
{
public void Customize(IFixture fixture)
{
fixture.Register<CalendarController>(() =>
{
// ----- ICalendarServiceClient mock setups -----
var calendarServiceClientMock = new Mock<ICalendarServiceClient>(MockBehavior.Strict);
calendarServiceClientMock.Setup(m => m.GetEvents(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<CancellationToken>()))
.ReturnsAsync(fixture.Create<EventList>()).Verifiable();
return new CalendarControllerBuilder()
.With(calendarServiceClientMock)
.Create();
});
}
}
My automoq data attribute (using AutoFixture.Xunit2):
public class Attributes
{
public class AutoMoqDataAttribute<T> : AutoDataAttribute where T : ICustomization, new()
{
public AutoMoqDataAttribute()
: base(() => new Fixture()
.Customize(
new CompositeCustomization(
new AutoMoqCustomization(),
new T())))
{
}
}
public class AutoMoqDataAttribute : AutoDataAttribute
{
public AutoMoqDataAttribute()
: base(() => new Fixture()
.Customize(
new AutoMoqCustomization()))
{
}
}
}
My test that works fine and uses the customization registration:
[Theory]
[AutoMoqData<CalenderControllerCustomization>]
public async Task Test_GetAllEvents_ClientIsCalledCorrectlyAndReturnsCorrectData(
IFixture fixture,
[Frozen] Mock<ICalendarServiceClient> calendarServiceClientMock,
CalendarController sut)
{
// Arrange
var startDate = fixture.Create<DateTimeOffset>();
var endDate = fixture.Create<DateTimeOffset>();
// Act
var eventList = await sut.GetAllEvents(startDate, endDate);
// Assert
eventList.Events.Count.Should().Be(3); // fixture always create 3 of lists here
calendarServiceClientMock.Verify();
}
THE PROBLEM:
Now I want to override the setup with my own data returned.
[Theory]
[AutoMoqData<CalenderControllerCustomization>]
public async Task Test_GetAllEvents_ClientIsCalledCorrectlyAndReturnsCorrectData_Overridden(
IFixture fixture,
[Frozen] Mock<ICalendarServiceClient> calendarServiceClientMock,
CalendarController sut)
{
// Arrange
var startDate = fixture.Create<DateTimeOffset>();
var endDate = fixture.Create<DateTimeOffset>();
var result = fixture.Build<EventList>()
.With(x => x.Events, fixture.CreateMany<Event>(5).ToList())
.Create();
// override client mock setup:
calendarServiceClientMock.Setup(m => m.GetEvents(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<CancellationToken>()))
.ReturnsAsync(fixture.Build<EventList>()
.With(x => x.Events, fixture.CreateMany<Event>(5).ToList())
.Create()).Verifiable();
// Act
var eventList = await sut.GetAllEvents(startDate, endDate);
// Assert
eventList.Events.Count.Should().Be(5); // FAILS - IT GETS 3 AND NOT 5
calendarServiceClientMock.Verify(); // THIS FAILS TOO IF I SET 3 IN ABOVE
}
I have tried with and without the Frozen attribute.
What am I missing here? I don't want to call my calendarcontroller builder as the point is to avoid boilerplate. Do I need a registration of the client or something else I'm missing
(maybe related to Override Autofixture customization setup but using moq and not n-subtitute. Could not get this to work even with correct order of parameters)
Thanks for reading!

With the current way you customize the fixture I don't think you can. By creating a custom builder and instantiating the mock by hand you've basically painted yourself in a corner.
To get AutoFixture to control the instances you need in the test, you must allow it to generate them. Here's a possible solution.
The root of your SUT is the controller. Let's say it receives as a parameter an ICalendarService that's always the concrete implementation CalendarService.
To tell AutoFixture that the implementation is always a concrete type you can relay the resolved type to the concrete implementation.
fixture.Customizations.Add(new TypeRelay(typeof(ICalendarService), typeof(CalendarService)));
Next the service takes as a constructor parameter an abstraction that's ICalendarClient which is resolved as the wrapper but only for the service. This means you have to identify the constructor parameter and relay the request to the wrapper type.
fixture.Customizations.Add(new FilteringSpecimenBuilder(
new FixedRequestRelay(typeof(CalendarClientWrapper)),
new YourConstructorParameterSpecification()));
The YourConstructorParameterSpecification is a IRequestSpecification implementation that identifies a request as a parameter of type ICalendarClient that belongs to the constructor of type CalendarService.
FixedRequestRelay is a simple ISpecimenBuilder that always resolves the same predefined request from ISpecimenContext instead of the received one.
Here's a very basic implementation of it.
public record FixedRequestRelay(object Request) : ISpecimenBuilder
{
public object Create(object request, ISpecimenContext context)
=> context.Resolve(this.Request);
}
Next you have your wrapper that also takes as a parameter an abstraction of type ICustomerClient. However this instance you want to be resolved as a mock that you can control from the test. Since you use AutoFixure.AutoMoq you can leave this one as is and let AutoMoq generate a mock for it.
Let's say this is the resulting customization.
public class CalendarCustomization : ICustomization
{
public void Customize(IFixture fixture)
{
fixture.Customizations.Add(new TypeRelay(typeof(ICalendarService), typeof(CalendarService)));
fixture.Customizations.Add(new FilteringSpecimenBuilder(
new FixedRequestRelay(typeof(CalendarClientWrapper)),
new AndRequestSpecification(
new ParameterSpecification(typeof(ICalendarClient), "client"),
new ParameterMemberSpecification(
new DeclaringTypeSpecification(
new ExactTypeSpecification(typeof(CalendarService)))))));
}
}
By using it you can write a test like this.
[Theory, MyData]
public async Task Foo(
[MinLength(5)] Event[] events,
[Frozen] Mock<ICalendarClient> clientMock,
CalendarController controller,
DateTime start, DateTime end)
{
clientMock
.Setup(x => x.GetAllEvents(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<CancellationToken>()))
.ReturnsAsync(events);
var actual = await controller.GetAllEvents(start, end, default);
Assert.Equal(events, actual);
}

Nunit testing with Mock. Instance of Interface

I have the following (simplified) code.
public class Controller
{
private readonly IService _service;
public Controller(IService service)
{
_service = service;
}
public async Task<IHttpActionResult> Create(MyObject object)
{
var result = _service.method(object);
if (!result.Succeeded)
{
return this.GetErrorResult(object);
}
}
}
and SimpleInjector is used to inject the dependency between _service and its implementation class, like this:
public static void Register(Container container)
{
container.Register<IService, Service>();
}
As a note, injection and unit testing are new to me so I do not fully understand them, but am learning.
If I run the application through Swagger, all is working fine.
As a note, the Register function is called when I run the application through Swagger.
Now, I am trying to setup some unit tests using NUnit, and am Mocking the IService object like this:
var Service = new Mock<IService>();
Controller _controller = new Controller(Service.Object);
_controller.Create(new MyObject object());
which seems to be correct to me so far - although I am not sure?
The problem is that for the unit test, result is always null - I think the is because there is a problem with my Mock of the interface - it does not seem to be finding the method - it never steps into it and does not show up int he debugger.
As a note, for the unit test, the Register method does not get called. I did try calling it to register the dependency, but it does not help.
As I said above, this is all new to me and I am on the edge of my understanding on all of this.
I am out of ideas and do not know where to look from here, so any help would be greatly appreciated.
EDIT:
The original question had the following:
public async Task<IHttpActionResult> Create(string content)
which I have updated to:
public async Task<IHttpActionResult> Create(MyObject object)
Can anyone advise how I can pass in a generic reference to MyObject on the setup, without having to make an instance of this class.
So basically I want to tell it that an instance of this class will be passed in, without creating that instance.
I have tried the following:
Service.Setup(x => x.method(It.IsAny<MyObject>())
but it says cannot convert MethodGroup to MyObject
and here is the definition of IService:
public interface IService
{
IdentityResult method(ApplicationUser user, UserLoginInfo login);
}

You need to configure the Mock object to return something for IService.method as follows:
var Service = new Mock<IService>();
Service.Setup(x => x.method(It.IsAny<string>())
.Returns<string>(str => **whatever result you need**);
With the addition of your actual IService definition, you should change the Setup call to:
Service.Setup(x => x.method(It.IsAny<ApplicationUser>(), It.IsAny<UserLoginInfo>())
.Returns<ApplicationUser, UserLoginInfo>((user, login) => new IdentityResult(true));

The setup method has to be called on the Mock object.
var Service = new Mock<IService>();
Service.Setup(x=>x.method("argument")).Returns(YourReturnObject)
Controller _controller = new Controller(Service.Object);

Using your simplified example
public class Controller
{
private readonly IService _service;
public Controller(IService service)
{
_service = service;
}
public async Task<IHttpActionResult> Create(string content)
{
var result = await _service.method(content);
if (!result.Succeeded)
{
return this.GetErrorResult(result);
}
return Ok();
}
}
Lets assume IService is defined as
public interface IService {
Task<Result> method(string input);
}
public class Result {
public bool Succeeded { get; set; }
}
For the unit test you need to setup the mock to fake the actions wanted for the test
public async Task Controller_Given_Content_Should_Return_Ok() {
//Arrange
var input = "content";
var mockService = new Mock<IService>();
mockService
.Setup(m => m.method(input))
.ReturnAsync(new Result { Succeeded = true });
var _controller = new Controller(mockService.Object);
//Act
var result = await _controller.Create(input);
//Assert
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result,typeof(OkResult));
}
Given that the method under test is asynchronous you would want to setup the test to be asynchronous as well.

How I can test a particular method in my Service class using Mock C#?

Please help me with my issue. I have a Service class which is given below:
public class RateService:IRatesService
{
...
public RatesDTO GetById(int Id)
{
return Mapper.Map<Rates, RatesDTO>(this.db.Rates.GetAll().Where(m => m.RateId == Id).First());
}
}
An interface IRatesServicelooks like that sample of code:
public interface IRatesService
{
.....
RatesDTO GetById(int Id);
....
}
And now I try to test public RatesDTO GetById(int Id) method. My code is given below:
[TestClass]
public class UnitTest1
{
[TestMethod]
public void TestMethod1()
{
Mock<IRatesService> mock = new Mock<IRatesService>();
mock.Setup(m => m.GetById(It.IsAny<int>())).Returns<RatesDTO>(total=>total);
Assert.IsNotNull(mock.Object.GetById(1));
}
}
But when I run test I get an error like this:
Test Name: TestMethod1 Test
FullName: Provider.Tests.Services.UnitTest1.TestMethod1
Result Message:
Test method Provider.Tests.Services.UnitTest1.TestMethod1 threw
exception: System.ArgumentException: Невозможно преобразовать объект
типа "System.Int32" к типу "Provider.BLL.DTO.RatesDTO".
What is the best practice to test the Service classes and methods?

You are trying to test your mock. That doesn't make any sense.
You should strive to test your actual code.
In your case, you might want to make sure that your GetById returns RatesDTO with the right id value.
You could use Mock framework, to facilitate your testing.
e.g. if you are trying to perform a unit-test and you are using a DB layer you might want to mock the database layer GetAll function and return several objects and then run a test to check that you actually return the right object (same id).

Your RateService is the system under test. When creating mocks for your unit tests the norm is to mock the dependencies of your system under test.
So given your current service lets say it has a dependency on a data store.
public class RateService : IRatesService {
private readonly IDbContext db;
public RateService(IDbContext dbContext) {
this.db = dbContext;
}
//...
public RatesDTO GetById(int Id) {
return Mapper.Map<Rates, RatesDTO>(this.db.Rates.GetAll().Where(m => m.RateId == Id).First());
}
//...
}
IDbContext would be the dependency of the system under test.
You would mock that up when testing RateService
[TestClass]
public class RateServiceUnitTests {
[TestMethod]
public void Given_ValidId_GetById_Should_Return_Dto() {
//Arrange
var validId = 1;
var fakes = new List<Rates>() {
new Rates { RateId = validId }
};
var mock = new Mock<IDbContext>();
//Assuming IDbContext.Rates.GetAll() returns an IEnumerable<Rates>
mock.Setup(m => m.Rates.GetAll()).Returns(fakes);
var sut = new RateService(mock.Object);
//Act
var result = sut.GetById(validId);
//Assert
Assert.IsNotNull(result);
}
}
Noticed that you are also using a mapper. You should make sure that is configured for the test as well otherwise the test will fail. When using static calls in your classes they can cause issues when you try to isolate your system for testing. Try adding the mapper as a dependency as well.

NSubstitute creating two instances of substituted instance

I've got a base ApiController for my controllers to inherit:
public BaseApiController(ILogger logger) : ApiController
{
private readonly ILogger _logger;
public BaseApiController(ILogger logger)
{
_logger = logger.ForContext("SomeContext");
}
}
And a simple controller that's inheriting from the base controller:
public SomeController : BaseApiController
{
public SomeController(ILogger logger) : base(logger)
{ }
public IHttpActionResult SomeAction()
{
_logger.Information("Start doing something...");
//Do stuff...
_logger.Information("End doing something...");
return Ok();
}
}
I've created a simple test for the controller using Xunit and Nsubstitute:
public void SomeAction_ReturnsOk()
{
//Arrange
var logger = Substitute.For<ILogger>();
var controller = new SomeController(logger) {
Request = Substitute.For<HttpRequestMessage>()
};
//Act
var result = controller.SomeAction();
//Assert
logger.ReceivedWithAnyArgs().Information(Arg.Any<string>());
}
When executing the test case, it fails stating that it has received zero calls to the logger.Information() method. When debugging the _receivedCalls property (on the substituted ILogger), if the debug context is within the test case itself it is showing a single call to the logger.ForContext() method (which was called on the base class constructor), however when looking at the debug within the context of the controller.SomeAction() method, the same _receivedCalls property shows the two calls to logger.Information() as would be expected but not the call to ForContext().
So it appears to me that for some reason Nsubstitute is creating two separate instances of the substitute class, one in the context of the base controller and one in the actual controller - why is this and how can I avoid it?

You need to stub the ForContext return like this:
public void SomeAction_ReturnsOk()
{
//Arrange
var logger = Substitute.For<ILogger>();
logger.ForContext(Arg.Any<string>()).Returns(logger);
var controller = new SomeController(logger) {
Request = Substitute.For<HttpRequestMessage>()
};
//Act
var result = controller.SomeAction();
//Assert
logger.Received().Information(Arg.Any<string>());
}
I change the assert to:
logger.Received().Information(Arg.Any<string>());
OR:
logger.ReceivedWithAnyArgs().Information("");

Unit Testing with DbContext mock through Service Layer

I'm a beginner at writing unit tests and I have a test I'm trying to get working. I'll start of by explaining what I'm trying to test.
I'm trying to test a method which saves messages in a Mvc 4 project. The method is called SaveMessage and is shown below.
namespace ChatProj.Service_Layer
{
public class UserService : IUserService
{
public MessageContext messageContext = new MessageContext();
public UserService()
{
_messageRepository = new MessageRepository(messageContext);
}
private IMessageRepository _messageRepository;
-> public void SaveMessage(Message message)
{
messageContext.Messages.Add(message);
_messageRepository.Save();
}
The _messageRepository.Save in the SaveMessage method is implemented in my DAL layer MessageRepository and looks like this:
public void Save()
{
context.SaveChanges();
}
This way of saving will seem a bit overcomplicated, but I structured the project this way because I didn't want the service layer (IUserService & UserService) to handle operations that could & should (i think) be handled by the Data Access Layer (IMessageRepository & MessageRepository).
Now comes the tricky part. I've been trying to understand how I could unit test this. This is my try:
namespace ChatProj.Tests
{
[TestFixture]
class MessageRepositoryTests
{
[SetUp]
public void Setup()
{
}
[Test]
public void SaveMessage_SaveWorking_VerifyUse()
{
//Arrange
var userServiceMock = new Mock<UserService>();
var message = new Message { MessageID = 0, Name = "Erland", MessageString = "Nunit Test", MessageDate = DateTime.Now };
var repositoryMock = new Mock<IMessageRepository>();
var contextMock = new Mock<MessageContext>();
MessageRepository messageRepository = new MessageRepository(contextMock.Object);
UserService userService = new UserService();
//Act
userService.SaveMessage(message);
//Assert
repositoryMock.Verify(m => m.Save());
userServiceMock.Verify(m => m.SaveMessage(message));
}
}
I get this error: Imgur link , and I'm not quite sure how to solve it. I've tried looking at several other SO posts but I fail to make the test work.
So I'm wondering, how do I practically get my Unit Test to work?

You should setup your MessageContext properties to return fake data and don't make real Db call with SaveChanges method.
Right now it still tries to access a real DB.
But you can setup only virtual properties or if it will be an inteface.
So the best solution is to extract an interface from your MessageContext and inject it into repository. Then you can easily mock your IMessageContext interface and force it to return appropriate in-memory data.

Take a look at these two lines:
UserService userService = new UserService();
//Act
userService.SaveMessage(message);
You're creating a userService instance, and then immediately saving your message. Now jump into the SaveMessage code.
public void SaveMessage(Message message)
{
messageContext.Messages.Add(message);
_messageRepository.Save();
}
Ok, now you're adding stuff to messageContext, and then calling _messageRepository.Save(). But where are messageContext and _messageRepository instantiated?
public MessageContext messageContext = new MessageContext();
public UserService()
{
_messageRepository = new MessageRepository(messageContext);
}
You're creating them at instantiation. The mocks that you've created in your test aren't being used. Instead of creating instances of these objects in the constructor, you might consider passing them into the UserService constructor as arguments. Then, you can pass in mocked instances in your test.