I have a small system that uses Jonathan Oliver's CommonDomain and EventStore.
How can I unit test my aggregate roots in order to verify that correct events are raised?
Consider following aggregate root:
public class Subscriber : AggregateBase
{
private Subscriber(Guid id)
{
this.Id = id;
}
private Subscriber(Guid id, string email, DateTimeOffset registeredDate)
: this(id)
{
this.RaiseEvent(new NewSubscriberRegistered(this.Id, email, registeredDate));
}
public string Email{ get; private set; }
public DateTimeOffset RegisteredDate { get; private set; }
public static Subscriber Create(Guid id, string email, DateTimeOffset registeredDate)
{
return new Subscriber(id, email, registeredDate);
}
private void Apply(NewSubscriberRegistered #event)
{
this.Email = #event.Email;
this.RegisteredDate = #event.RegisteredDate;
}
}
I would like to write a following test:
// Arrange
var id = Guid.NewGuid();
var email = "test#thelightfull.com";
var registeredDate = DateTimeOffset.Now;
// Act
var subscriber = Subscriber.Create(id, email, registeredDate);
// Assert
var eventsRaised = subscriber.GetEvents(); <---- How to get the events?
// Assert that NewSubscriberRegistered event was raised with valid data
I could set up whole EventStore with memory persistence and synchronous dispatcher, hook up mock event handler and store any published events for verification, but it seems a bit of overkill.
There is an interface IRouteEvents in CommonDomain. Looks like I could mock it to get the events directly from AggregateBase but how would I actually pass it to my Subscriber class? I don't want to 'pollute' my domian with testing-related code.
I've found out that AggregateBase explicitly implements IAggregate interface, which exposes ICollection GetUncommittedEvents(); method.
So the unit test looks like that:
var eventsRaised = ((IAggregate)subscriber).GetUncommittedEvents();
and no dependency on EventStore is required.
I just pushed up NEventStoreExample with code I gathered in various places (StackOverflow, Documently, Greg Young's skillcast).
It's a very basic implementation of NEventStore that uses CommonDomain to rebuild aggregate state and an EventSpecification base test class to test aggregate behaviour.
Here is a fairly simple test fixture that uses NUnit and ApprovalTests to test CommonDomain aggregate roots . (ApprovalTests is not required - just kinda makes life simple).
The assumption is that
1) the fixture is instantiated with an aggregate (perhaps already set in a certain state) along with a series of 'given' events to be applied.
2) the test will then invoke a specific command handler as part of the TestCommand method - current expectation is a Func that returns the command that is handled
3) the aggregate snapshot, commands, and events all contain 'rich' ToString methods
The TestCommand method then compares the expected with the approved interactions within the aggregate.
public class DomainTestFixture<T>
where T : AggregateBase
{
private readonly T _agg;
private readonly StringBuilder _outputSb = new StringBuilder();
public DomainTestFixture(T agg, List<object> giveEvents)
{
_agg = agg;
_outputSb.AppendLine(string.Format("Given a {0}:", agg.GetType().Name));
giveEvents.ForEach(x => ((IAggregate) _agg).ApplyEvent(x));
_outputSb.AppendLine(
giveEvents.Count == 0
? string.Format("with no previously applied events.")
: string.Format("with previously applied events:")
);
giveEvents.ForEach(x => _outputSb.AppendLine(string.Format(" - {0}", x)));
((IAggregate) _agg).ClearUncommittedEvents();
var snapshot = ((IAggregate) _agg).GetSnapshot();
_outputSb.AppendLine(string.Format("which results in the state: {0}", snapshot));
}
public void TestCommand(Func<T, object> action)
{
var cmd = action.Invoke(_agg);
_outputSb.AppendLine(string.Format("When handling the command: {0}", cmd));
_outputSb.AppendLine(string.Format("Then the {0} reacts ", _agg.GetType().Name));
var raisedEvents = ((IAggregate) _agg).GetUncommittedEvents().Cast<object>().ToList();
_outputSb.AppendLine(
raisedEvents.Count == 0
? string.Format("with no raised events")
: string.Format("with the following raised events:")
);
raisedEvents.ForEach(x => _outputSb.AppendLine(string.Format(" - {0}", x)));
var snapshot = ((IAggregate) _agg).GetSnapshot();
var typ = snapshot.GetType();
_outputSb.AppendLine(string.Format("and results in the state: {0}", snapshot));
Approvals.Verify(_outputSb.ToString());
Assert.Pass(_outputSb.ToString());
}
}
and an example usage
[Test]
public void Test_Some_Aggregate_Handle_Command()
{
var aggId = Guid.Empty;
var tester = new DomainTestFixture<PartAggregate>(
new PartAggregate(aggId, null),
new List<object>()
{
new PartOrdered(),
new PartReceived()
}
);
tester.TestCommand(
(agg) =>
{
var cmd = new RejectPart();
agg.Handle(cmd);
return cmd;
});
}
Related
I am using EF Core in a projet to get stored procedure calling. In my context i have the following :
public class MyContext : DbContext
{
public DbQuery<User> UserQuery { get; set; }
public MyContext(DbContextOptions<MyContext> options) : base(options) { }
}
And i call the stored procedure like this :
public virtual async Task<User> GetUserAsync(string name)
{
return await MyContext.Query<User>()
.FromSql($"EXEC [dbo].[GetUser], #Login = {name}")
.FirstOrDefaultAsync();
}
Code is working fine. I need to test this method in unit tests, i'm using InMemoryDatabase to mock my context MyContext like this :
[Fact]
public async Task GetUserAsync_should_return_first_user_with_login_and_password_if_exists()
{
// Arrange
var users = new List<User>
{
new User()
{
Login = "test#outlook.fr",
Password = "pass1",
},
};
var options = new DbContextOptionsBuilder<MyContext>()
.UseInMemoryDatabase(databaseName: "BddName")
.Options;
var context = new MyContext(options);
var loginProvider = A.Fake<LoginProvider>(opts => opts.WithArgumentsForConstructor(() => new LoginProvider(context)));
// Act
// Assert
context.Dispose();
}
And i have no idea how can i set my list into the result of the stored procedure called from DbQuery. I tried to follow this article : https://nodogmablog.bryanhogan.net/2017/11/unit-testing-entity-framework-core-stored-procedures/ but it works for DbSet only and not DbQuery.
I need some advices for this case.
Thanks in advance.
The link in the OP does apply to the DbQuery type as well, as you're mocking the provider. Both DbSet and DbQuery work in the same way in this regard.
See https://stackoverflow.com/a/56940311/2975810 for a previous answer on the topic.
I'm quite new to unit testing and I need an hand to understand if I'm doing things in the correct way. My major problem is regarding the DB testing... Here's my code then I'll expose my perplexities
Consider this class that's an item of a pipeline I've to perform
public class RetrieveApplicationUsernamePipelineStep : IPipelineStep
{
public const string RetrieveApplicationUsernameKey = "RetrieveApplicationUsername";
private readonly IRetrieveApplicationUserRepository repository;
public int Order => 3;
public string Name => RetrieveApplicationUsernameKey;
public RetrieveApplicationUsernamePipelineStep(IRetrieveApplicationUserRepository repository)
{
this.repository = repository;
}
public async Task<IDictionary<string, object>> Action(IDictionary<string, object> context)
{
string res = await repository.GetApplicationUser(context);
context[Resources.ApplicationUser] = res;
return context;
}
}
I wrote the following tests
[TestFixture]
public class RetrieveApplicationUsernamePipelineStepTests
{
private IRetrieveApplicationUserRepository retrieveApplicationUserRepository;
[OneTimeSetUp]
public void Start()
{
var configuration = new ConfigurationFromConfigFile();
retrieveApplicationUserRepository = new RetrieveApplicationUserRepository(configuration);
}
[Test]
public async Task ActionSuccessfullyCompleted()
{
var context = new Dictionary<string, object>();
var repository = Substitute.For<IRetrieveApplicationUserRepository>();
repository.GetApplicationUser(context).Returns("user1");
var pipeline = new RetrieveApplicationUsernamePipelineStep(repository);
var res = await pipeline.Action(context);
Assert.IsNotNull(res[Resources.ApplicationUser]);
Assert.IsNotEmpty((string)res[Resources.ApplicationUser]);
}
[Test]
public void ActionFailingCompleted()
{
var context = new Dictionary<string, object>();
var repository = Substitute.For<IRetrieveApplicationUserRepository>();
repository.GetApplicationUser(context).Throws(new UserMappingNotFoundException());
var pipeline = new RetrieveApplicationUsernamePipelineStep(repository);
Assert.ThrowsAsync<UserMappingNotFoundException>(async () => await pipeline.Action(context));
}
[Test]
public void NameTest()
{
var pipeline = new RetrieveApplicationUsernamePipelineStep(retrieveApplicationUserRepository);
Assert.IsTrue(pipeline.Name == RetrieveApplicationUsernamePipelineStep.RetrieveApplicationUsernameKey);
}
[Test]
public void OrderTest()
{
var pipeline = new RetrieveApplicationUsernamePipelineStep(retrieveApplicationUserRepository);
Assert.IsTrue(pipeline.Order == 3);
}
}
And those test works fine since for ActionSuccessfullyCompleted and ActionFailingCompleted I substitute the IRetrieveApplicationUserRepository's result with my expected one.
The real implementation of ther repository is
public class RetrieveApplicationUserRepository : IRetrieveApplicationUserRepository
{
#region Variables
private readonly IConfiguration configuration;
#endregion
#region Ctor
public RetrieveApplicationUserRepository(IConfiguration configuration)
{
this.configuration = configuration;
}
#endregion
#region IRetrieveApplicationUserRepository
public async Task<string> GetApplicationUser(IDictionary<string, object> context)
{
if (configuration.AppSettings[Resources.ApplicationUserFromDomainUserKey] == null)
throw new KeyNotFoundException(Resources.ApplicationUserFromDomainUserKey);
if (string.IsNullOrEmpty(configuration.ConnectionString))
throw new NullReferenceException();
string storedProcedure = configuration.AppSettings.Get(Resources.ApplicationUserFromDomainUserKey);
string result;
using (var sqlConnection = new SqlConnection(configuration.ConnectionString))
{
using (var sqlCommand = new SqlCommand(storedProcedure, sqlConnection))
{
sqlCommand.CommandType = CommandType.StoredProcedure;
sqlCommand.Parameters.AddWithValue("#DOMAINUSER", context[Resources.DomainUser]);
sqlCommand.Parameters.AddWithValue("#DOMAIN", context[Resources.DomainName]);
sqlCommand.Parameters.AddWithValue("#APPID", context[Resources.ApplicationId]);
sqlConnection.Open();
result = (string)await sqlCommand.ExecuteScalarAsync();
}
}
if (result == null)
throw new UserMappingNotFoundException();
return result;
}
#endregion
}
Here're the questions :
Are the test I wrote correct?
I've seen using Resharper's Code Coverage that it wants me to test-cover the properties...is there a way I can avoid this? is this test meaningful?
What's your approach when you've to unit test component that're related to DB? Have you got a real-db that's used for test? Consider that the real DB is about 10Gb so I don't want to have a copy as mdf (condider I can have this) just to test a small portion of the DB
Talking with my colleagues they told me to use test just for TDD while I wish to use them to avoid regressions
Going back to the DB question, I don't want to have a test where I write if username is "John" and maybe tomorrow John user won't be present in the DB anymore,so that the test I expect to pass wont' pass anoymore
The usual approach is to isolate the database side with an abstraction, so you can provide a test dummy (mock, fake, etc) of that abstraction. Only test an actual database when you do the integration testing.
For the tests of database stored procedures, you may well want a different test harness, creating a new test database in memory (equivalently, in a RAM-backed filesystem). You only need to populate enough data for the individual test (we're doing functional testing here, not performance testing), and you may be able to retain table structure across tests with judicious use of rollback.
I have done this, but it's some time ago, so I'll refrain from giving examples that may be no longer state-of-the-art (even if the code does still exist, and if I could find it).
I am planning to write an ActionFilter for business validation and in which some services will be resolved via Service Locator(I know this is not good practice and as far as possible i avoid Service Locator pattern, but for this case i want to use it).
OnActionExecuting method of the filter is something like this:
public override void OnActionExecuting(ActionExecutingContext actionContext)
{
// get validator for input;
var validator = actionContext.HttpContext.RequestServices.GetService<IValidator<TypeOfInput>>();// i will ask another question for this line
if(!validator.IsValid(input))
{
//send errors
}
}
Is it possible to write unit test for above ActionFilterand how?
Here is an sample on how to create a mock (using XUnit and Moq framework) to verify that the IsValid method is called and where the mock returns an false.
using Dealz.Common.Web.Tests.Utils;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.Extensions.DependencyInjection;
using Moq;
using System;
using Xunit;
namespace Dealz.Common.Web.Tests.ActionFilters
{
public class TestActionFilter
{
[Fact]
public void ActionFilterTest()
{
/****************
* Setup
****************/
// Create the userValidatorMock
var userValidatorMock = new Mock<IValidator<User>>();
userValidatorMock.Setup(validator => validator
// For any parameter passed to IsValid
.IsValid(It.IsAny<User>())
)
// return false when IsValid is called
.Returns(false)
// Make sure that `IsValid` is being called at least once or throw error
.Verifiable();
// If provider.GetService(typeof(IValidator<User>)) gets called,
// IValidator<User> mock will be returned
var serviceProviderMock = new Mock<IServiceProvider>();
serviceProviderMock.Setup(provider => provider.GetService(typeof(IValidator<User>)))
.Returns(userValidatorMock.Object);
// Mock the HttpContext to return a mockable
var httpContextMock = new Mock<HttpContext>();
httpContextMock.SetupGet(context => context.RequestServices)
.Returns(serviceProviderMock.Object);
var actionExecutingContext = HttpContextUtils.MockedActionExecutingContext(httpContextMock.Object, null);
/****************
* Act
****************/
var userValidator = new ValidationActionFilter<User>();
userValidator.OnActionExecuting(actionExecutingContext);
/****************
* Verify
****************/
// Make sure that IsValid is being called at least once, otherwise this throws an exception. This is a behavior test
userValidatorMock.Verify();
// TODO: Also Mock HttpContext.Response and return in it's Body proeprty a memory stream where
// your ActionFilter writes to and validate the input is what you desire.
}
}
class User
{
public string Username { get; set; }
}
class ValidationActionFilter<T> : IActionFilter where T : class, new()
{
public void OnActionExecuted(ActionExecutedContext context)
{
throw new NotImplementedException();
}
public void OnActionExecuting(ActionExecutingContext actionContext)
{
var type = typeof(IValidator<>).MakeGenericType(typeof(T));
var validator = (IValidator<T>)actionContext.HttpContext
.RequestServices.GetService<IValidator<T>>();
// Get your input somehow
T input = new T();
if (!validator.IsValid(input))
{
//send errors
actionContext.HttpContext.Response.WriteAsync("Error");
}
}
}
internal interface IValidator<T>
{
bool IsValid(T input);
}
}
HttpContextUtils.cs
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using System.Collections.Generic;
namespace Dealz.Common.Web.Tests.Utils
{
public class HttpContextUtils
{
public static ActionExecutingContext MockedActionExecutingContext(
HttpContext context,
IList<IFilterMetadata> filters,
IDictionary<string, object> actionArguments,
object controller
)
{
var actionContext = new ActionContext() { HttpContext = context };
return new ActionExecutingContext(actionContext, filters, actionArguments, controller);
}
public static ActionExecutingContext MockedActionExecutingContext(
HttpContext context,
object controller
)
{
return MockedActionExecutingContext(context, new List<IFilterMetadata>(), new Dictionary<string, object>(), controller);
}
}
}
As you can see, it's quite a mess, you need to create plenty of mocks to simulate different responses of the actuall classes, only to be able to test the ActionAttribute in isolation.
I like #Tseng's above answer but thought of giving one more answer as his answer covers more scenarios (like generics) and could be overwhelming for some users.
Here I have an action filter attribute which just checks the ModelState and short circuits(returns the response without the action being invoked) the request by setting the Result property on the context. Within the filter, I try to use the ServiceLocator pattern to get a logger to log some data(some might not like this but this is an example)
Filter
public class ValidationFilterAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext context)
{
if (!context.ModelState.IsValid)
{
var logger = context.HttpContext.RequestServices.GetRequiredService<ILogger<ValidationFilterAttribute>>();
logger.LogWarning("some message here");
context.Result = new JsonResult(new InvalidData() { Message = "some messgae here" })
{
StatusCode = 400
};
}
}
}
public class InvalidData
{
public string Message { get; set; }
}
Unit Test
[Fact]
public void ValidationFilterAttributeTest_ModelStateErrors_ResultInBadRequestResult()
{
// Arrange
var serviceProviderMock = new Mock<IServiceProvider>();
serviceProviderMock
.Setup(serviceProvider => serviceProvider.GetService(typeof(ILogger<ValidationFilterAttribute>)))
.Returns(Mock.Of<ILogger<ValidationFilterAttribute>>());
var httpContext = new DefaultHttpContext();
httpContext.RequestServices = serviceProviderMock.Object;
var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
var actionExecutingContext = new ActionExecutingContext(
actionContext,
filters: new List<IFilterMetadata>(), // for majority of scenarios you need not worry about populating this parameter
actionArguments: new Dictionary<string, object>(), // if the filter uses this data, add some data to this dictionary
controller: null); // since the filter being tested here does not use the data from this parameter, just provide null
var validationFilter = new ValidationFilterAttribute();
// Act
// Add an erorr into model state on purpose to make it invalid
actionContext.ModelState.AddModelError("Age", "Age cannot be below 18 years.");
validationFilter.OnActionExecuting(actionExecutingContext);
// Assert
var jsonResult = Assert.IsType<JsonResult>(actionExecutingContext.Result);
Assert.Equal(400, jsonResult.StatusCode);
var invalidData = Assert.IsType<InvalidData>(jsonResult.Value);
Assert.Equal("some messgae here", invalidData.Message);
}
I have this simple Saga in Rebus:
public void MySaga : Saga<MySagaData>
IAmInitiatedBy<Event1>
IHandleMessages<Event2>
{
private IBus bus;
private ILog logger;
public MySaga(IBus bus, ILog logger)
{
if (bus == null) throw new ArgumentNullException("bus");
if (logger == null) throw new ArgumentNullException("logger");
this.bus = bus;
this.logger = logger;
}
protected override void CorrelateMessages(ICorrelationConfig<MySagaData> config)
{
config.Correlate<Event>(m => m.MyObjectId.Id, s => s.Id);
config.Correlate<Event>(m => m.MyObjectId.Id, s => s.Id);
}
public Task Handle(Event1 message)
{
return Task.Run(() =>
{
this.Data.Id = message.MyObjectId.Id;
this.Data.State = MyEnumSagaData.Step1;
var cmd = new ResponseCommandToEvent1(message.MyObjectId);
bus.Send(cmd);
});
}
public Task Handle(Event2 message)
{
return Task.Run(() =>
{
this.Data.State = MyEnumSagaData.Step2;
var cmd = new ResponseCommandToEvent2(message.MyObjectId);
bus.Send(cmd);
});
}
}
and thanks to the kind mookid8000 I can test the saga using FakeBus and a SagaFixture:
[TestInitialize]
public void TestInitialize()
{
var log = new Mock<ILog>();
bus = new FakeBus();
fixture = SagaFixture.For<MySaga>(() => new MySaga(bus, log.Object));
idTest = new MyObjectId(Guid.Parse("1B2E7286-97E5-4978-B5B0-D288D71AD670"));
}
[TestMethod]
public void TestIAmInitiatedBy()
{
evt = new Event1(idTest);
fixture.Deliver(evt);
var testableFixture = fixture.Data.OfType<MySagaData>().First();
Assert.AreEqual(MyEnumSagaData.Step1, testableFixture.State);
// ... more asserts
}
[TestMethod]
public void TestIHandleMessages()
{
evt = new Event2(idTest);
fixture.Deliver(evt);
var testableFixture = fixture.Data.OfType<MySagaData>().First();
Assert.AreEqual(MyEnumSagaData.Step2, testableFixture.State);
// ... more asserts
}
[TestCleanup]
public void TestCleanup()
{
fixture.Dispose();
bus.Dispose();
}
The first test method that check IAmInitiatedBy is correctly executed and no error is thrown, while the second test fail. It looks like a correlation issues since fixture.Data contains no elements and in fixture.LogEvents contains as last elements this error: Could not find existing saga data for message Event2/b91d161b-eb1b-419d-9576-2c13cd9d9c51.
What is this GUID? Is completly different from the one I defined in the unit test? Any ideas? Is legal what I'm tryng to test (since I'm using an in-memory bus)?
This line is bad: this.Data.Id = message.MyObjectId.Id. If you checked the value of Data.Id before you overwrote it, you would have noticed that the property already had a value.
You do not assign the saga ID - Rebus does that. And you should leave that property alone :)
Regarding your error - when Rebus wants to log information about a specific message, it logs a short name for the type and the message ID, i.e. the value of the automatically-assigned rbs2-msg-id header. In other words: It's not the value of the property m.MyObjectId.Id, you're seeing, it's the message ID.
Since the saga fixture is re-initialized for every test run, and you only deliver an Event2 to it (which is not allowed to initiate a new instance), the saga will not be hit.
I am trying to test the AddCategory of the following CategoryService.
My problem is that I am having a hard time understanding what to mock/fake.
My attempt at the test is at the bottom.
I am using MOQ, xUnit and FluentAssertions.
I am using FluentValidation for the validators.
Category Service
public class CategoryService : ValidatingServiceBase, ICategoryService
{
private readonly IUnitOfWork unitOfWork;
private readonly IRepository<Category> categoryRepository;
private readonly IRepository<SubCategory> subCategoryRepository;
private readonly IValidationService validationService;
public CategoryService(
IUnitOfWork unitOfWork,
IRepository<Category> categoryRepository,
IRepository<SubCategory> subCategoryRepository,
IValidationService validationService)
: base(validationService)
{
this.unitOfWork = unitOfWork;
this.categoryRepository = categoryRepository;
this.subCategoryRepository = subCategoryRepository;
this.validationService = validationService;
}
public bool AddCategory(Category category)
{
var validationResult = validationService.Validate(category);
if (!validationResult.IsValid)
{
return false;
}
else
{
categoryRepository.Add(category);
return true;
}
}
public bool DoesCategoryExist(string categoryName)
{
return categoryRepository.Query().SingleOrDefault(x => x.Name == categoryName) != null;
}
}
Validation Service
public class ValidationService : ServiceBase, IValidationService
{
private readonly IValidatorFactory validatorFactory;
public ValidationService(IValidatorFactory validatorFactory)
{
Enforce.ArgumentNotNull(validatorFactory, "validatorFactory");
this.validatorFactory = validatorFactory;
}
public ValidationResult Validate<TEntity>(TEntity entity) where TEntity : class
{
var validator = validatorFactory.GetValidator<TEntity>();
return validator.Validate(entity);
}
}
Validator Factory
public class ValidatorFactory : IValidatorFactory
{
public IValidator GetValidator(Type type)
{
Enforce.ArgumentNotNull(type, "type");
return DependencyResolver.Current.GetService(typeof(IValidator<>).MakeGenericType(type)) as IValidator;
}
public IValidator<T> GetValidator<T>()
{
return DependencyResolver.Current.GetService<IValidator<T>>();
}
}
Category Validator
public class CategoryValidator : AbstractValidator<Category>
{
public CategoryValidator(ICategoryService service)
{
RuleFor(x => x.Name)
.NotEmpty()
.Must((category, name) =>
{
return service.DoesCategoryExist(name);
});
}
}
Unit Test Attempt
[Fact]
public void AddCategory_Should_ReturnTrue()
{
var category = new Category() { Name = "Cat1" };
var unitOfWork = new Mock<IUnitOfWork>();
var categoryRepo = new Mock<IRepository<Category>>();
var subCategoryRepo = new Mock<IRepository<SubCategory>>();
var mockCategoryService = new Mock<ICategoryService>();
var categoryValidator = new CategoryValidator(mockCategoryService.Object);
var validatorFactory = new Mock<IValidatorFactory>();
validatorFactory.Setup(x => x.GetValidator<CategoryValidator>()).Returns(categoryValidator as IValidator<CategoryValidator>);
var validationService = new ValidationService(validatorFactory.Object);
var categoryService = new CategoryService(
unitOfWork.Object,
categoryRepo.Object,
subCategoryRepo.Object,
validationService);
categoryService.AddCategory(category);
}
Well for the AddCategory method, I think you really only need two mocks, one for the ValidationService, and one for the CategoryRepository, because the other dependencies aren't exercised in that function and therefore are irrelevant
(the story might be different of course if your ctor throws on null arguments but in this case I think you are OK - albeit you might consider adding these checks in the future :)
Anyway, being pedantic, I'd nearly be inclined to write two (or more - maybe one for null input to verify it throws or returns false or whatever) "unit" tests for this function;
One to verify that given an invalid category, the function returns false,
One to verify that given a valid category, the function calls Add on the CategoryRepository dependency.
So it would look like this (sorry, this is using MSTest syntax as I'm not familiar with xUnit but it's the same idea). Also have not tested below for typos, etc :)
public void AddCategory_InvalidCategory_ShouldReturnFalse()
{
//Arrange
var mockValidator = new Mock<IValidator>();
//no matter what we pass to the validator, it will return false
mockValidator.Setup(v=>v.Validate(It.IsAny<Category>()).Returns(false);
var sut= new CategoryService(null,null,null,mockValidator.Object);
bool expected = false;
//ACT
bool actual = sut.AddCategory(new Category());
//ASSERT
Assert.AreEqual(expected,actual,"Validator didn't return false as expected");
}
public void AddCategory_ValidCategory_ShouldCallRepositoryAdd()
{
//Arrange
var mockValidator = new Mock<IValidator>();
//no matter what we pass to the validator, it will return true
mockValidator.Setup(v=>v.Validate(It.IsAny<Category>()).Returns(true);
var mockRepo = new Mock<IRepository<SubCategory>>();
mockRepo.Setup(r=>r.Add(It.IsAny<Category>())); //do not know or care what happens as this is a void method.
var sut= new CategoryService(null,mockRepo.Object,null,mockValidator.Object);
bool expected = false;
//ACT
bool actual = sut.AddCategory(new Category());
//ASSERT
mockRepo.Verify(r=>r.Add(It.IsAny<Category>(),Times.Exactly(1),"Repo ADD method not called or called too many times, etc");
Assert.AreEqual(expected,actual,"Add was called BUT the AddCategoryMethod didn't return true as expected"); //and of course you could be totally pedantic and create a new test method for that last assert ;)
}
The reason I favour this approach is because it forces you to consider the behaviour of the method under test, as well as ensuring that you don't involve any dependencies that are not being tested plus it means your test methods only create exactly what they need to in order to run the tests (and of course you can create some setup/teardown helpers to pre-create those mocks for you);
Of course you could put all the above into a single method but for the sake of saving a few LOC I hope you'll agree that having two separate tests to verify two separate behaviours is a more robust approach.
Just my 2c. hope it helps!