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Moq checking if method is called with parameter from another call

I have the following function that I am trying to put under unit test
public MessageListDto GetMessageList(SimpleSearchCriteria criteria)
{
var messages = _repository.GetMessages(criteria, out int total);
return new MessageListDto(messages, total);
}
and the following is my test so far, in which I am able to determine that _repository.GetMessages is call with the correct parameters.
However, how do I test that the second line is tested properly, I need to test that
A new object of type MessageListDto is constructed with the two parameters returned from the line above
the newly constructed object is returned
[Test]
public void Test1()
{
int total = 10;
var searchCriteria = new SimpleSearchCriteria();
var mockRepo = new Mock<IMessageRepository>();
var messageService = new MessageService(mockRepo.Object);
messageService.GetMessageList(searchCriteria);
mockRepo.Verify(r => r.GetMessages(searchCriteria, out total), Times.Once);
mockRepo.Verity ??????????
}

As we have discussed in the comment section your goal is to test the returned messages is passed to the dto's constructor without any modification.
With your current code you can't do that because you are creating the DTO explicitly inside your method. So, you can't replace it with a spy.
Just to clarify some terminologies:
Dummy: simple code that returns bogus data
Fake: a working alternative which can take shortcuts
Stub: custom logic with predefined data
Mock: custom logic with expectations (interactive stub)
Shim: custom logic at run-time
Spy: interceptors to record calls
To be able to capture the arguments of the MessageListDto constructor call you need to introduce an other layer between your GetMessageList method and the constructor. (In other words indirection)
For the sake of simplicity let me assume that IMessageRepository's GetMessages returns a string array.
So, you can introduce an interface like this:
public interface IDtoProvider
{
public MessageListDto CreateMessageList(string[] messages, int total)
=> new MessageListDto(messages, total);
}
Here I have used C# 8's interface default implementation feature
It can be further shortened with C# 9's target-typed new expression feature
If you are using older C# version then you need to separate the interface and the default implementation from each other
Now lets amend your MessageService to receive a IDtoProvider instance via its constructor
class MessageService
{
private readonly IMessageRepository _repository;
private readonly IDtoProvider _dtoProvider;
public MessageService(IMessageRepository repository, IDtoProvider dtoProvider)
=> (_repository, _dtoProvider) = (repository, dtoProvider);
public MessageListDto GetMessageList(SimpleSearchCriteria criteria)
{
var messages = _repository.GetMessages(criteria, out int total);
return _dtoProvider.CreateMessageList(messages, total);
}
...
}
Here I've took advantage of ValueTuple's deconstruct capability
With these in our hand we can write a unit test like this:
//Arrange - Repo
string[] messages = new[] { "OnlyElement" };
int total = 10;
var mockRepo = new Mock<IMessageRepository>();
mockRepo
.Setup(repo => repo.GetMessages(It.IsAny<SimpleSearchCriteria>(), out total))
.Returns(messages);
//Arrange - Provider
var dto = new MessageListDto(messages, total);
string[] messagesArgument = null;
int totalArgument = -1;
var mockProvider = new Mock<IDtoProvider>();
mockProvider
.Setup(provider => provider.CreateMessageList(It.IsAny<string[]>(), It.IsAny<int>()))
.Callback<string[], int>((messages, total) => (messagesArgument, totalArgument) = (messages, total))
.Returns(dto);
//Arrange - SUT
var searchCriteria = new SimpleSearchCriteria();
var sut = new MessageService(mockRepo.Object, mockProvider.Object);
//Act
sut.GetMessageList(searchCriteria);
//Assert - Repo
mockRepo.Verify(r => r.GetMessages(searchCriteria, out total), Times.Once);
//Assert - Provider
Assert.Equal(messages, messagesArgument);
Assert.Equal(total, totalArgument);
I've defined how should the IMessageRepository mock behave
I've defined how should the IDtoProvider mock behave
2.1 I've used here the Callback method to capture the calling argument
2.2 If you perform multiple calls against your mocked method then please consider to use Capture.In
I've instantiated a MessageService (which is our system under test) with the mock objects
I've called the GetMessageList inside the Act phase
I've made assertion against the repo mock call
I've made assertion against the calling parameters of the CreateMessageList
6.1 Here I have used xunit's assertion

The first step is to setup the MessageService mock, so that it returns something deterministic and then in the second step you verify that that has been used to construct your MessageListDto.
[Test]
public void Test1()
{
// arrange
int total = 10;
var searchCriteria = new SimpleSearchCriteria();
var messages = new [] {"message1", "message2"} // or similar
var mockRepo = new Mock<IMessageRepository>();
// or similar, I am not quite certain as to the specific syntax. Especially wrt. out parameters. Check the documentation.
mockRepo.Setup(x => x.GetMessages(It.IsAny<SimpleSearchCriteria>(), It.IsAny<int>())).Returns(messages);
var messageService = new MessageService(mockRepo.Object);
// act
var result = messageService.GetMessageList(searchCriteria);
// assert
mockRepo.Verify(r => r.GetMessages(searchCriteria, out total), Times.Once);
// or similar; here you might want to check out FluentAssertions as #Peter Csala suggested
Assert.Equal(result.Messages, messages);
}

What's missing from previous answers is that whenever possible, you should set up the mocked method with the exact parameters, that you expect it to receive. In other words set up the method with concrete values instead of It.IsAny<>(). In such case you won't have to verify the method later at all. (Unless it's critical to test, how many times a method is called). Simply, if mocked GetMessages receives different arguments than expected, it will return null, set total to 0 and your test will fail. Having the mocked methods set up properly, you can now focus on verifying what GetMessageList returns, which is the purpose of this unit test.
[Test]
public void Test1()
{
int total = 10;
var messages = new[] {new Message()};
var searchCriteria = new SimpleSearchCriteria();
var mockRepo = new Mock<IMessageRepository>();
mockRepo.Setup(_ => _.GetMessages(searchCriteria, out total))
.Returns(messages);
var messageService = new MessageService(mockRepo.Object);
var dto = messageService.GetMessageList(searchCriteria);
Assert.AreSame(messages, dto.Messages);
Assert.AreEqual(total, dto.Total);
}

Unit test result in null object while testing a web api 2

I am new to MS Unit Testing and Moq objects. I am trying to test my Web API 2 controller. I have given below my unit test and controller code. While stepping through the code, it doesn't even go to the GetDeliveryCodeStrategy method.
[TestMethod]
public void CreateDelivery_ShouldReturnDeliveryCode()
{
Mock<IDeliveryStrategy> deliveryStrategy = new Mock<IDeliveryStrategy>
();
Mock<IDeliveryCode> deliveryCode = new Mock<IDeliveryCode>();
var controller = new DeliveryCodeController(deliveryStrategy.Object,
deliveryCode.Object);
var controllerContext = new HttpControllerContext();
var request = new HttpRequestMessage();
request.Headers.Add("appToken", "a57ffa87-950e-40f4-b965-17788becac7d");
controllerContext.Request = request;
controller.ControllerContext = controllerContext;
var result = controller.CreateDelivery(50) as
CreatedNegotiatedContentResult<IDeliveryCode>;
Assert.IsNotNull(result);
}
public class DeliveryCodeController : ApiController
{
IDeliveryStrategy _deliveryBatch;
IDeliveryCode _deliveryCode;
//Constructor dependency injection through Autofac
public DeliveryCodeController(IDeliveryStrategy DeliveryBatch,
IDeliveryCode deliveryCode)
{
_deliveryBatch = DeliveryBatch;
_deliveryCode = deliveryCode;
}
[HttpPost]
[Route("api/DeliveryCode/{percentage}")]
public IHttpActionResult CreateDelivery(int percentage)
{
String appToken = String.Empty;
if (Request.Headers.TryGetValues("appToken", out IEnumerable<String>
headerValues))
{
appToken = headerValues.FirstOrDefault();
}
if (!String.IsNullOrEmpty(appToken)))
{
IDeliveryContext deliveryContext =
_deliveryBatch.GetDeliveryCodeStrategy(percentage);
_deliveryCode.Code = deliveryContext.Create();
return Created(Request.RequestUri.ToString(), _deliveryCode);
}
else
{
return Content(HttpStatusCode.Forbidden, new Error { message = "The App
Token is not valid." });
}
}
}
When I do the "Debug Test" and step through the code, the deliveryContext
object comes as null in the code IDeliveryContext deliveryContext =
_deliveryBatch.GetDeliveryCodeStrategy(percentage);

You have to set up the Mock to return a certain value:
IDeliveryContext deliveryContext = // ???? - whatever you want it to be.
// Could be another Mock.
// This is what the Mock will return.
Mock<IDeliveryStrategy> deliveryStrategy = new Mock<IDeliveryStrategy>();
deliveryStrategy.Setup(x => x.GetDeliveryCodeStrategy(It.IsAny<decimal>()))
.Returns(deliveryContext);
This tells the Mock that that when its GetDeliveryCodeStrategy method is called, it should return the specified IDeliveryContext. Depending on what you're trying to do, that could be another Mock. (Mocks that return mocks are undesirable, but if you're starting out I'd file that detail away and come back to it.)
I'm guessing that percentage is a decimal. It.IsAny<decimal>() means that the mock doesn't care what the value is. That's usually okay because what you're testing is what your class does with the object returned by the mock.

You need to call Setup() on mock objects for the methods that you want to use:
var deliveryStrategy = new Mock<IDeliveryStrategy>();
deliveryStrategy.Setup(x => x.GetDeliveryCodeStrategy(It.IsAny<int>))
.Returns(AMockOfDeliveryContext); //you need to mock it beforehand so you can
//use the object here

How to mock a method inside the same class being tested?

I am creating some unit tests for a method ValidateObject in a service ObjectService. The ValidateObject method calls another method ValidateObjectPropertyB. I want to mock the calls to the last method.
The ObjectService and relevant method look like this:
public class ObjectService : IObjectService
{
public bool ValidateObject(object objectToValidate)
{
return
!String.IsNullOrEmpty(objectToValidate.PropertyA) &&
ValidateObjectPropertyB(objectToValidate.PropertyB, currentUserId);
}
public bool ValidateObjectPropertyB(long propertyB, long userId)
{
return validationResult;
}
}
Right now my Test class ObjectServiceTest contains the following code:
public class ObjectServiceTest
{
var objectToValidate = new Object(validPropertyA, validPropertyB);
using(var mock = new AutoMock.GetStrict())
{
var mockObjectService = new Mock<IObjectService>();
mockObjectService.callBase = true;
mockObjectService.Setup(s => s.ValidateObjectPropertyB(objectToValidate.PropertyB, _user.Id)).Returns(true);
var service = mock.Create<ObjectService>();
var result = service.ValidateObject(objectTovalidate);
Assert.IsTrue(result);
}
}
The above test fails because result is false, the for PropertyA succeeds
What am I doing wrong?

ValidateObject works in part by calling ValidateObjectPropertyB. I am presuming you are wanting to mock this second method so that you can demonstrate that ValidateObject does indeed call ValidateObjectPropertyB (provided !String.IsNullOrEmpty(objectToValidate.PropertyA) evaluates to true)
If this is the case then you are testing implementation detail, which generally you shouldn't do. Consider a function that took two integer values and returned their sum, you would want to verify that when this function was passed 3 and 5 it returned 8, you should not test that it arrived at this answer by using a particular method/class under the hood because this is not relevant to the desired outcome and should in future you decide you wished to refactor your code the test would likely start failing even if the code still returned the desired result.
Looking at your code, it seems that return value of ValidateObject is not directly dependent on the method call to ValidateObjectPropertyB but rather the value of validationResult. It is this value that you must set to properly test ValidateObject.
One way to achieve what you are asking would be to make ValidateObjectPropertyB virtual, then create a derived class that overrides this method to return what ever you want. However I do not recommend doing this purely for the sake of unit testing.

Moq setting method return value

I have the below class, and I am trying to test the method AddRecordToQueue.
I am using Moq to mock the result of the the AddToQueue method within the AddRecordToQueue method.
The AddToQueue method returns a boolean, so i am trying to mock the result with a true value
public class Test
{
private readonly IRabbitMqConnection rabbitMqConnection;
public Test(IRabbitMqConnection rabbitMqConnection)
{
this.rabbitMqConnection = rabbitMqConnection;
}
public bool AddRecordToQueue(string messageExchange, object data)
{
var jsonified = JsonConvert.SerializeObject(data);
var customerBuffer = Encoding.UTF8.GetBytes(jsonified);
var result = this.rabbitMqConnection.AddToQueue(customerBuffer, messageExchange);
return result;
}
}
My test class looks like the below.
[TestClass]
public class TestCon
{
[TestMethod]
public void MockTest()
{
Moq.Mock<IRabbitMqConnection> rabbitConection = new Moq.Mock<IRabbitMqConnection>();
var draftContactsManager = new Test(rabbitConection.Object);
rabbitConection.Setup(e => e.AddToQueue(null, string.Empty)).Returns((bool res) => true);
var result = draftContactsManager.AddRecordToQueue("someExchange", null);
Assert.IsTrue(result);
}
}
I cant seem to set the moq result as true. Can anyone advise what I am missing
thanks

I think that you need to change the Returns to just return true instead of the lambda. Like this:
rabbitConection.Setup(e => e.AddToQueue(null, string.Empty)).Returns(true)
EDIT:
If this still doesn't work then it is probably due to the parameters not matching. You are passing in "someExchange" but the mock is set up for string.Empty. If you aren't sure what values will be used you could use the It.IsAny method to get around this.
rabbitConection.Setup(e => e.AddToQueue(It.IsAny<byte[]>(), It.IsAny<string>())).Returns(true)

You need to setup the method with the actual arguments it's invoked.
If JsonConvert.SerializeObject(data) returns null, then this is the setup:
rabbitConection.Setup(e => e.AddToQueue(null, "someExchange")).Returns(true)
Additionally, you can setup the method to return true/false regardless of values of the arguments:
rabbitConection.Setup(e => e.AddToQueue(It.IsAny<byte[]>(), It.IsAny<string>())).Returns(true)
With the above setup, the method will return true no matter what what you've passed to the method. The previous example will return true only when the method is called with the setuped arguments.

As the others said, the Setup is incorrect.
You need to call Setup before using the associated Object
It should be something similar to:
...
rabbitConection
.Setup(e => e.AddToQueue(It.IsAny<byte[]>(), It.IsAny<string>()))
.Returns(true);
var draftContactsManager = new Test(rabbitConection.Object);
...

Using Rhino Mocks how can I set a property of a parameter for a Mocked method

Using the new Rhino Mocks 3.5 Arrange/Act/Assert (AAA) Testing style, I'm having problems writing a test.
I have a method that calls a method on a repository class. ActivateFoo, where my Foo object has an IsActive property. The result of the ActivateFoo object should change the property.
Here is sample code:
[TestMethod]
public void Should_update_foo_to_active_inside_of_repository()
{
// arrange
var repo = MockRepository.GenerateMock<IRepository>();
var foo = new Foo() { ID = 1, IsActive = false };
var target = new Presenter(repo);
repo.Expect(x => x.ActivateFoo(foo)).Return(true);
// act
target.Activate(foo);
// assert
Assert.IsTrue(foo.IsActive);
repo.VerifyAllExpectations();
}
I'm guessing that the key piece of code would be inbetween "ActivateFoo(foo))." and "Return(true);".
One point to clarify how the method chaining stuff works behind the scenes, If there is code written on the line I expect, does it matter if it is after Return() or before? (unless of course the solution is using the MethodOptions overload of Expect, or something else).
Thanks in advance for any help.

Thanks to AB Kolan this is the resulting code I used and works.
[TestMethod]
public void Should_update_foo_to_active_inside_of_repository()
{
// arrange
var repo = MockRepository.GenerateMock<IRepository>();
var foo = new Foo() { ID = 1, IsActive = false };
var target = new Presenter(repo);
repo.Expect(x => x.ActivateFoo(foo)).
Do(new Func<Foo, bool>(
delegate(Foo f) { f.IsActive = true; return true; }
));
// act
target.Activate(foo);
// assert
Assert.IsTrue(foo.IsActive);
repo.VerifyAllExpectations();
}
I tend to not like to have to have extra methods of functions for single use of a test, preferring an inline delegate if possible.
To address the issue of is this something I should be doing or not as far as the design. As the names are there, this isn't the exact code and inside of the target.Activate() method. The code in Activate() does some checking and if needed, will do the repository ActivateFoo(), and then check the result of that operation and do other things.
So, it might be possible that at a later time I will have to refactor this out and separate the steps, but for now, I've got it to work.
Thanks

You might want to try something out like this using the Do handler. I honestly feel ActivateFoo should be void return type. But here's the code for ActivateFoo with bool return type.
[TestMethod]
public void Should_update_foo_to_active_inside_of_repository()
{
// arrange
var repo = MockRepository.GenerateMock<IRepository>();
var foo = new Foo() { ID = 1, IsActive = false };
var target = new Presenter(repo);
repo.Expect(x => x.ActivateFoo(foo)).
Do(new ActivateFooDelegate(ActivateFooDelegateInstance));
// act
target.Activate(foo);
// assert
Assert.IsTrue(foo.IsActive);
repo.VerifyAllExpectations();
}
private delegate bool ActivateFooDelegate(Foo f);
public bool ActivateFooDelegateInstance(Foo f)
{
f.IsActive = true;
return f.IsActive;
}

I was not really using this version of RhinoMocks yet, but in the old versions you would have to use a .Do(appropriate delegate) to set the flag and return the value (instead of .Return).
Please let me know if it works, if not I can play around with it.

From the looks of it, ActivateFoo should be a void method. And since you are mocking it out, you shouldn't be verifying that it changes anything on your object.
You would verify that the IsActive property is changed when you were testing your repository method ActivateFoo, not when you are testing the Activate method on the presenter.