Currently we are trying to implement some unittesting on our services. In the below service an order is created and a audit registration is made about the creation of an order. When writing the two tests (because we think the tests should be seperated to get tests with 1 responsibility) this was where I started with:
public class TestPacklineOrderManagementService
{
[Fact]
public void CreateNewProductWhenNoPacklineOrderIsAvailable()
{
IPackLineOrderRepository packLineOrderRepository = Substitute.For<IPackLineOrderRepository>();
packLineOrderRepository.GetActive(Arg.Any<PackLine>()).Returns(x => null);
var rawProductRepository = Substitute.For<IRawProductRepository>();
rawProductRepository.Get(1).Returns(new RawProduct {Id = 1});
var packlineRepository = Substitute.For<IPackLineRepository>();
packlineRepository.Get(1).Returns(new PackLine {Id = 1});
var auditRegistrationService = Substitute.For<IAuditRegistrationService>();
var packlineOrderManagementService = new PacklineOrderManagementService(packLineOrderRepository, rawProductRepository, packlineRepository, auditRegistrationService);
packlineOrderManagementService.SetProduct(1,1);
packLineOrderRepository.Received()
.Insert(Arg.Is<PackLineOrder>(x => x.PackLine.Id == 1 && x.Product.Id == 1));
}
[Fact]
public void AuditCreateNewProductWhenNoPacklineOrderIsAvailable()
{
IPackLineOrderRepository packLineOrderRepository = Substitute.For<IPackLineOrderRepository>();
packLineOrderRepository.GetActive(Arg.Any<PackLine>()).Returns(x=>null);
var rawProductRepository = Substitute.For<IRawProductRepository>();
rawProductRepository.Get(1).Returns(new RawProduct { Id = 1 });
var packlineRepository = Substitute.For<IPackLineRepository>();
packlineRepository.Get(1).Returns(new PackLine { Id = 1 });
var auditRegistrationService = Substitute.For<IAuditRegistrationService>();
var packlineOrderManagementService = new PacklineOrderManagementService(packLineOrderRepository, rawProductRepository, packlineRepository, auditRegistrationService);
packlineOrderManagementService.SetProduct(1, 1);
auditRegistrationService.Received()
.Audit(Arg.Is<PackLineOrderAudit>(item => item.Action == PackLineOrderAction.CreatePacklineOrder));
}
}
As you can see a lot of duplicate code. To prevent this I tried to refactor this and it resulted in the code below:
public class TestPacklineOrderManagementService2
{
[Fact]
public void CreateNewProductWhenNoPacklineOrderIsAvailable()
{
IPackLineOrderRepository packLineOrderRepository;
IAuditRegistrationService auditRegistrationService;
var packlineOrderManagementService = BuilderForCreateNewProductWhenNoPacklineOrderIsAvailable(out packLineOrderRepository, out auditRegistrationService);
packlineOrderManagementService.SetProduct(1,1);
packLineOrderRepository.Received().Insert(Arg.Any<PackLineOrder>());
}
[Fact]
public void AuditCreateNewProductWhenNoPacklineOrderIsAvailable()
{
IPackLineOrderRepository packLineOrderRepository;
IAuditRegistrationService auditRegistrationService;
var packlineOrderManagementService = BuilderForCreateNewProductWhenNoPacklineOrderIsAvailable(out packLineOrderRepository, out auditRegistrationService);
packlineOrderManagementService.SetProduct(1, 1);
auditRegistrationService.Received()
.Audit(Arg.Is<PackLineOrderAudit>(item => item.Action == PackLineOrderAction.CreatePacklineOrder));
}
private PacklineOrderManagementService BuilderForCreateNewProductWhenNoPacklineOrderIsAvailable(out IPackLineOrderRepository packLineOrderRepository,
out IAuditRegistrationService auditRegistrationService)
{
packLineOrderRepository = CreatePackLineOrderRepository(x => null);
auditRegistrationService = CreateAuditRegistrationService();
var rawProductRepository = CreateRawProductRepository(x => new RawProduct { Id = 1 });
var packlineRepository = CreatePacklineRepository(x => new PackLine { Id = 1 });
var packlineOrderManagementService = new PacklineOrderManagementService(packLineOrderRepository,
rawProductRepository, packlineRepository, auditRegistrationService);
return packlineOrderManagementService;
}
private IPackLineOrderRepository CreatePackLineOrderRepository(Func<CallInfo, PackLineOrder> getActiveResult)
{
IPackLineOrderRepository packLineOrderRepository = Substitute.For<IPackLineOrderRepository>();
packLineOrderRepository.GetActive(Arg.Any<PackLine>()).Returns(getActiveResult);
return packLineOrderRepository;
}
private IRawProductRepository CreateRawProductRepository(Func<CallInfo, RawProduct> getResult)
{
IRawProductRepository rawProductRepository = Substitute.For<IRawProductRepository>();
rawProductRepository.Get(1).Returns(getResult);
return rawProductRepository;
}
private IPackLineRepository CreatePacklineRepository(Func<CallInfo, PackLine> getResult)
{
IPackLineRepository packLineRepository = Substitute.For<IPackLineRepository>();
packLineRepository.Get(1).Returns(getResult);
return packLineRepository;
}
private IAuditRegistrationService CreateAuditRegistrationService()
{
return Substitute.For<IAuditRegistrationService>();
}
}
Is there any way to get a better code base for our unittests?
Better is very subjective, it depends a lot on how you define it. Some people might argue that your first example was better since all of the setup code is together in your test. I do have some feedback based on your code above though...
When you're writing tests, don't use the same value for two parameters to your system under test (SUT) unless they really are the same, it hides transposition errors. So, in your test, you're setting up one of your substitutes like this:
rawProductRepository.Get(1).Returns(new RawProduct {Id = 1});
Then calling your SUT:
packlineOrderManagementService.SetProduct(1,1);
Are the 1s in the SUT call related to the Repository setup? It's not at all clear which 1 is which...
This somewhat subjective, but if your test setup is exactly the same, do you really need to duplicate the test, with different asserts? Does it really make sense for the Audit to take place if the Insert hasn't etc?
If you do have groups of tests that have similar setups, then you could push the common bits into your classes constructor. You could also organise your tests using nested classes, something like this:
public class TestPacklineOrderManagementService
{
public class TestSetProduct {
IPackLineOrderRepository _packLineOrderRepository;
IRawProductRepository _rawProductRepository;
// etc
public TestSetProduct() {
_packLineOrderRepository = Substitute.For<IPackLineOrderRepository>();
_packLineOrderRepository.GetActive(Arg.Any<PackLine>()).Returns(x => null);
_rawProductRepository = Substitute.For<IRawProductRepository>();
// etc
}
[Fact]
public void CreateNewProductWhenNoPacklineOrderIsAvailable()
{
// Any test specific setup...
_packlineOrderManagementService.SetProduct(1,1);
_packLineOrderRepository.Received()
.Insert(Arg.Is<PackLineOrder>(x => x.PackLine.Id == 1
&& x.Product.Id == 1));
}
[Fact]
public void AuditCreateNewProductWhenNoPacklineOrderIsAvailable()
{
_packlineOrderManagementService.SetProduct(1, 1);
_auditRegistrationService.Received()
.Audit(Arg.Is<PackLineOrderAudit>(item =>
item.Action == PackLineOrderAction.CreatePacklineOrder));
}
}
public class TestSomeOtherScenario {
// tests...
}
}
This approach and make your tests more succinct and easier to follow, if they only contain the test specific information, but is it better? It's very subjective, some people (including the xunit team) don't like shared per test setups. Really it's about finding the approach that works for you and your team...
Related
I am trying to Test a function which I have below to get all active categories which will use a relation predicate bucket. The mocked data in the initializer class adds three objects which are both active and not deleted. It adds a fourth to the end which is deleted and not active.
During the test, the call will return all four objects, and not the expected number of three. This is where I am stuck with.
I have tried making _randomCategories as a Queryable object, but this also failed.
There is a lot of code in the first class so it may be hard to follow, so each part is broken into regions saying which part it performs, i.e. Test Setup, Mock Data, & the Tests themselves.
The Mock Data region are the expected results. May not be necessary for my needs here as it is not used in this other than to get the expected count, but it may be relevant to the overall structure of the tests.
CategoryServiceTests.cs
#region Test Setup
public class CategoryServiceFixture : IDisposable
{
public CategoryService Sut { get; private set; }
private SystemRepository SystemRepository { get; set; }
private Mock<CategoryRepository> _categoryRepositoryMock;
private List<CategoryEntity> _randomCategories;
public CategoryServiceFixture()
{
// Init Category List
_randomCategories = CategoryEntityInitializer.GetAllMockCategories();
// Init repository
_categoryRepositoryMock = new Mock<CategoryRepository>(new object[] { null });
// Setup mocking behavior
// BaseRepository
_categoryRepositoryMock
.Setup(m => m.GetAll(It.IsAny<IRelationPredicateBucket>(), It.IsAny<IDataAccessAdapter>()))
.Returns(_randomCategories);
SystemRepository = new SystemRepository(category: _categoryRepositoryMock.Object);
Sut = new CategoryService(this.SystemRepository);
}
public void Dispose()
{
//Sut.Dispose();
}
}
[CollectionDefinition("CategoryService Collection")]
public class CategoryServiceCollection : ICollectionFixture<CategoryServiceFixture> { }
#endregion
#region Mock Data
public static class CategoryRepositoryMockData
{
public static IEnumerable<object> GetCategories
{
get
{
yield return new object[] { 1, new List<CategoryEntity>() {
new CategoryEntity
{
CategoryId = 1,
Name = "Test1",
IsDeleted = false,
IsActive = true
},
new CategoryEntity
{
CategoryId = 2,
Name = "Test2",
IsDeleted = false,
IsActive = true
},
new CategoryEntity
{
CategoryId = 3,
Name = "Test3",
IsDeleted = false,
IsActive = true
}
}};
}
}
}
#endregion
#region Tests
[Collection("CategoryService Collection")]
public class CategoryServiceTests
{
private CategoryServiceFixture _fixture;
public CategoryServiceTests(CategoryServiceFixture fixture)
{
_fixture = fixture;
}
[Theory]
[Trait("Category", "Get All Active Categories")]
[Trait("Expected", "Return Correct")]
[MemberData("GetCategories", MemberType = typeof(CategoryRepositoryMockData))]
public void GetActiveCategories_ShouldReturn(int id, IList<CategoryEntity> expectedCategoryObjects)
{
var result = _fixture.Sut.GetActiveCategories();
Assert.Equal(expectedCategoryObjects.Count, result.Count);
}
}
#endregion
This class generates the mock database objects. This is what is supposed to be searched through and select the correct ones from the list.
CategoryEntityInitializer.cs
public static class CategoryEntityInitializer
{
public static List<CategoryEntity> GetAllMockCategories()
{
List<CategoryEntity> _categories = new List<CategoryEntity>();
for (var i = 1; i <= 3; i++)
{
var entity = new CategoryEntity()
{
CategoryId = i,
Name = String.Format("{0}{1}", "Test", i),
IsDeleted = false,
IsActive = true
};
_categories.Add(entity);
}
var lastEntity = new CategoryEntity()
{
CategoryId = 4,
Name = String.Format("{0}{1}", "Test", 4),
IsDeleted = true,
IsActive = false
};
_categories.Add(lastEntity);
return _categories;
}
}
This class is where the predicate is.
CategoryService.cs
public class CategoryService : BaseService
{
public IList<CategoryModel> GetActiveCategories()
{
var bucket = new RelationPredicateBucket();
bucket.PredicateExpression.Add(CategoryFields.IsDeleted == false);
bucket.PredicateExpression.Add(CategoryFields.IsActive == true);
var categoriesEntities = _systemRepository.Category.GetAll(bucket);
return CategoryMapper.MapToModels(categoriesEntities);
}
}
The rest of the code structure works fine for every other test and across different test classes. This is the first time I have had to test the relation predicate bucket.
UPDATE 18/05/16
I found the solution to the problem. Answer in the below code.
_categoryRepositoryMock
.Setup(m => m.GetAll(It.IsAny<IRelationPredicateBucket>(), It.IsAny<IDataAccessAdapter>()))
.Returns(new Func<IRelationPredicateBucket, IDataAccessAdapter, IEnumerable<CategoryEntity>>(
(bucket, adapter) => _randomCategories.Where(a => a.IsDeleted == false && a.IsActive == true)));
Old Answer 11/05/16
I believe I have found part of the answer. In mocking the repository, I was returning all four objects, no matter if the predicate bucket would work or not.
_categoryRepositoryMock
.Setup(m => m.GetAll(It.IsAny<IRelationPredicateBucket>(), It.IsAny<IDataAccessAdapter>()))
.Returns(_randomCategories);
This will cause it to return all four as I have not implemented the bucket to filter out the matches. I thought that the .Returns would place the data into the repository as if returned from the database and then get filtered with the bucket.
What I have found out is that the call to the repository does not go to the one it would if it was running normally, but instead goes to the mocked repository and this is where you need to filter the data to be returned.
It needs to be done something similar to this.
_categoryRepositoryMock
.Setup(m => m.GetAll(It.IsAny<IRelationPredicateBucket>(), It.IsAny<IDataAccessAdapter>()))
.Returns(
(IRelationPredicateBucket bucket) => _randomCategories.Where(x => x.Name.Equals(bucket)));
Although this still give me a problem as I don't know how to get inside the bucket to match to the list, it is at least heading in the correct direction.
NOTE: I have also found from searching that another reason for this type of failure is due to the code, in this case the function being called is too complex to be tested. It should be seperated into smaller chucks to make it less complex and to test each part seperately.
Before
public class CategoryService : BaseService
{
public IList<CategoryModel> GetActiveCategories()
{
var bucket = new RelationPredicateBucket();
bucket.PredicateExpression.Add(CategoryFields.IsDeleted == false);
bucket.PredicateExpression.Add(CategoryFields.IsActive == true);
var categoriesEntities = _systemRepository.Category.GetAll(bucket);
return CategoryMapper.MapToModels(categoriesEntities);
}
}
After
public class CategoryService : BaseService
{
public IList<CategoryModel> GetActiveCategories()
{
var bucket = GetActiveCategoriesBucket();
var categoriesEntities = _systemRepository.Category.GetAll(bucket);
return CategoryMapper.MapToModels(categoriesEntities);
}
public RelationPredicateBucket GetActiveCategoriesBucket()
{
var bucket = new RelationPredicateBucket();
bucket.PredicateExpression.Add(CategoryFields.IsDeleted == false);
bucket.PredicateExpression.Add(CategoryFields.IsActive == true);
return bucket;
}
}
I have the code below which I would like to test, but I'm not sure whether it is possible or not.
I have EF repositories and they are put together to a class as public properties. I don't know exactly whether it is bad solution or not, but it is easier to manage the code and its dependencies. Only the testability is still a question.
Purpose of my test is injecting data via
administrationRepository.ModuleScreen.GetAll()
method and catch the result. I know that it can be tested once it is deployed, but I want the tests in build time in order to have as fast feedback as possible.
I went through questions and answers here, but I cannot find answers. In my code I got to the point where the property is set up, but when I call the administrationRepoMock.Object.ModuleScreen.GetAll() ReSharper offers only the methods coming from Entitiy Framework and not the Moq related functions.
It is possible what I want? If so, how? Is my design suitable for this? If not can you give me articles, urls where I can see examples?
Repository:
public interface IModuleScreen
{
IEnumerable<DomainModel.Administration.ModuleScreen> GetAll();
}
public interface IAdministrationRepository
{
IModuleScreen ModuleScreen { get; }
}
public partial class AdministrationRepository : IAdministrationRepository
{
public virtual IModuleScreen ModuleScreen { get; private set; }
public AdministrationRepository( IModuleScreen moduleScreen )
{
this.ModuleScreen = moduleScreen;
}
}
Application:
public partial class DigitalLibraryApplication : IDigitalLibraryApplication
{
private IAdministrationRepository _administrationRepository;
private IMapper.IMapper.IMapper _mapper;
private IDiLibApplicationHelper _dilibApplicationHelper;
#region Ctor
public DigitalLibraryApplication( IAdministrationRepository administrationRepository, IMapper.IMapper.IMapper mapper, IDiLibApplicationHelper diLibApplicationHelper)
{
_administrationRepository = administrationRepository;
_mapper = mapper;
_dilibApplicationHelper = diLibApplicationHelper;
}
#endregion
public IEnumerable<ModuleScreenContract> GetModuleScreens()
{
//inject data here
IEnumerable<ModuleScreen> result = _administrationRepository.ModuleScreen.GetAll();
List<ModuleScreenContract> mappedResult = _mapper.MapModuleScreenToModuleScreenContracts(result);
return mappedResult;
}
}
Test code:
[Test]
public void ItCalls_ModuleRepository_Get_Method()
{
List<SayusiAndo.DiLib.DomainModel.Administration.ModuleScreen> queryResult = new List<SayusiAndo.DiLib.DomainModel.Administration.ModuleScreen>()
{
new DomainModel.Administration.ModuleScreen()
{
Id = 100,
},
};
var moduleScreenMock = new Mock<IModuleScreen>();
moduleScreenMock.Setup(c => c.GetAll()).Returns(queryResult);
administrationRepoMock.SetupProperty(c => c.ModuleScreen, moduleScreenMock.Object);
var mapperMock = new Mock<IMapper.IMapper.IMapper>();
var dilibApplicationHerlperMock = new Mock<IDiLibApplicationHelper>();
IDigitalLibraryApplication app = new DigitalLibraryApplication( administrationRepoMock.Object, mapperMock.Object, dilibApplicationHerlperMock.Object );
app.GetModules();
//issue is here
administrationRepoMock.Object.ModuleScreen.GetAll() //???
}
Here is a refactoring of your test that passes when run. You can update the pass criteria to suit you definition of a successful test.
[Test]
public void ItCalls_ModuleRepository_Get_Method() {
// Arrange
List<ModuleScreen> queryResult = new List<ModuleScreen>()
{
new ModuleScreen()
{
Id = 100,
},
};
//Building mapped result from query to compare results later
List<ModuleScreenContract> expectedMappedResult = queryResult
.Select(m => new ModuleScreenContract { Id = m.Id })
.ToList();
var moduleScreenMock = new Mock<IModuleScreen>();
moduleScreenMock
.Setup(c => c.GetAll())
.Returns(queryResult)
.Verifiable();
var administrationRepoMock = new Mock<IAdministrationRepository>();
administrationRepoMock
.Setup(c => c.ModuleScreen)
.Returns(moduleScreenMock.Object)
.Verifiable();
var mapperMock = new Mock<IMapper>();
mapperMock.Setup(c => c.MapModuleScreenToModuleScreenContracts(queryResult))
.Returns(expectedMappedResult)
.Verifiable();
//NOTE: Not seeing this guy doing anything. What's its purpose
var dilibApplicationHerlperMock = new Mock<IDiLibApplicationHelper>();
IDigitalLibraryApplication app = new DigitalLibraryApplication(administrationRepoMock.Object, mapperMock.Object, dilibApplicationHerlperMock.Object);
//Act (Call the method under test)
var actualMappedResult = app.GetModuleScreens();
//Assert
//Verify that configured methods were actually called. If not, test will fail.
moduleScreenMock.Verify();
mapperMock.Verify();
administrationRepoMock.Verify();
//there should actually be a result.
Assert.IsNotNull(actualMappedResult);
//with items
CollectionAssert.AllItemsAreNotNull(actualMappedResult.ToList());
//There lengths should be equal
Assert.AreEqual(queryResult.Count, actualMappedResult.Count());
//And there should be a mapped object with the same id (Assumption)
var expected = queryResult.First().Id;
var actual = actualMappedResult.First().Id;
Assert.AreEqual(expected, actual);
}
I am new to testing and have never used MSpec. I looked at tutorials and the only examples is "lite", like 1 + 1 should be 2. I need to test this real method and I don't know where to start.
public ILineItem CreateLineItem(BaseVariationContent sku, int quantityToAdd)
{
var price = sku.GetDefaultPrice();
var parent = sku.GetParentProducts().FirstOrDefault() != null ? _contentLoader.Get<ProductContent>(sku.GetParentProducts().FirstOrDefault()).Code : string.Empty;
return new LineItem
{
Code = sku.Code,
DisplayName = sku.DisplayName,
Description = sku.Description,
Quantity = quantityToAdd,
PlacedPrice = price.UnitPrice.Amount,
ListPrice = price.UnitPrice.Amount,
Created = DateAndTime.Now,
MaxQuantity = sku.MaxQuantity ?? 100,
MinQuantity = sku.MinQuantity ?? 1,
InventoryStatus = sku.TrackInventory ? (int)InventoryStatus.Enabled : (int)InventoryStatus.Disabled,
WarehouseCode = string.Empty, // TODO: Add warehouse id
ParentCatalogEntryId = parent,
};
}
BaseVariationContent is just a class with a lot of properties and that has an extension.
The MSpec github repo has a pretty nice README that explains the basic syntax components of an MSpec test class and test case.
https://github.com/machine/machine.specifications#machinespecifications
I won't fill in the details of your test, but I will show you the important parts to setup an mspec test.
[Subject("Line Item")]
public class When_creating_a_basic_line_item_from_generic_sku()
{
Establish context = () =>
{
// you would use this if the Subject's constructor
// required more complicated setup, mocks, etc.
}
Because of = () => Subject.CreateLineItem(Sku, Quantity);
It should_be_in_some_state = () => Item.InventoryStatus.ShouldEqual(InventoryStatus.Enabled);
private static Whatever Subject = new Whatever();
private static BaseVariationContent Sku = new GenericSku();
private static int Quantity = 1;
private static ILineItem Item;
}
You'll want to run these tests, so use the command-line tool
https://github.com/machine/machine.specifications#command-line-reference
or one of the integrations
https://github.com/machine/machine.specifications#resharper-integration
Let me navigate to you with a real implementation.
Let's assume you have a service called SiteService and it returns the current siteId (you have multiple siteIds for your application).
you want to write a test case, when requesting the current site it should return the site id definition in configuration.
you will need to create a test class (standard class file), let's give a meaningful name like "SiteServiceSpec.cs"
Next, you will need to mock the ISiteConfiguration so that it can get the site id from the SiteConfiguration
public abstract class SiteServiceContext : WithFakes
{
Establish context = () =>
{
var siteConfiguration = An<ISiteConfiguration>();
siteConfiguration.WhenToldTo(x => x.Id)
.Return(CurrentSiteId);
Repository = An<IRepository<WebSite.Domain.Site.Site>>();
SUT = new SiteService(siteConfiguration, Repository);
};
protected const short CurrentSiteId = 1;
protected static SiteService SUT;
protected static IRepository<WebSite.Domain.Site.Site> Repository;
}
Now, here comes the example of the test class.
[Subject(typeof(SiteService))]
public class When_requesting_current_site : SiteServiceContext
{
It should_return_site_with_id_defined_in_configuration = () =>
Result.Id.ShouldEqual(CurrentSiteId);
Establish context = () =>
{
var site = An<WebSite.Domain.Site.Site>();
site.WhenToldTo(x => x.Id)
.Return(CurrentSiteId);
Repository.WhenToldTo(x => x.GetById(CurrentSiteId))
.Return(site);
};
Because of = () =>
Result = SUT.GetCurrentSite();
static WebSite.Domain.Site.Site Result;
}
I hope it will help you to get an idea of how it works. Besides, follow the structure provided by #anthony-mastrean
I'm using handwritten fakes for a demo app but I'm not sure I'm using the mock appropriately. Here's my code below:
[Fact]
public void TransferFund_WithInsufficientAccountBalance_ThrowsException()
{
IBankAccountRepository stubRepository = new FakeBankAccountRepository();
var service = new BankAccountService(stubRepository);
const int senderAccountNo = 1, receiverAccountNo = 2;
const decimal amountToTransfer = 400;
Assert.Throws<Exception>(() => service.TransferFund(senderAccountNo, receiverAccountNo, amountToTransfer));
}
[Fact]
public void TransferFund_WithSufficientAccountBalance_UpdatesAccounts()
{
var mockRepository = new FakeBankAccountRepository();
var service = new BankAccountService(mockRepository);
const int senderAccountNo = 1, receiverAccountNo = 2;
const decimal amountToTransfer = 100;
service.TransferFund(senderAccountNo, receiverAccountNo, amountToTransfer);
mockRepository.Verify();
}
Test double:
public class FakeBankAccountRepository : IBankAccountRepository
{
private List<BankAccount> _list = new List<BankAccount>
{
new BankAccount(1, 200),
new BankAccount(2, 400)
};
private int _updateCalled;
public void Update(BankAccount bankAccount)
{
var account = _list.First(a => a.AccountNo == bankAccount.AccountNo);
account.Balance = bankAccount.Balance;
_updateCalled++;
}
public void Add(BankAccount bankAccount)
{
if (_list.FirstOrDefault(a => a.AccountNo == bankAccount.AccountNo) != null)
throw new Exception("Account exist");
_list.Add(bankAccount);
}
public BankAccount Find(int accountNo)
{
return _list.FirstOrDefault(a => a.AccountNo == accountNo);
}
public void Verify()
{
if (_updateCalled != 2)
{
throw new Xunit.Sdk.AssertException("Update called: " + _updateCalled);
}
}
}
the second test instantiates the fake and refers to it as mock, then it calls the verify method. Is this approach right or wrong?
That's how mocking frameworks work
You either make assumptions about interactions between components (usually done via various Expect-family methods) and later Verify them (your second test)
Or you tell your test double to behave in a certain way (Stub, Setup) because it's necessary in the flow (your first test)
The approach is correct but it's reinventing the wheel all over again. Unless you have very good reasons to do so, I'd invest some time into learning and using one of mocking frameworks (Moq or FakeItEasy come to mind).
I've hit a snag when using Moq to simulate an dependency which is called a large number of times. When I call Verify, Moq takes a long time (several minutes) to respond, and sometimes crashes with a NullReferenceException (I guess this is understandable, given the amount of data that Moq would have to accumulate to do the Verify from a "cold start").
So my question is, is there another strategy that I can use to do this using Moq, or should I revert to a hand-crafted stub for this rather unusual case. Specifically, is there a way to tell Moq up front that I'm only interested in verifying specific filters on the parameters, and to ignore all other values?
Neither of the approaches below is satisfactory.
Given CUT and Dep:
public interface ISomeInterface
{
void SomeMethod(int someValue);
}
public class ClassUnderTest
{
private readonly ISomeInterface _dep;
public ClassUnderTest(ISomeInterface dep)
{
_dep = dep;
}
public void DoWork()
{
for (var i = 0; i < 1000000; i++) // Large number of calls to dep
{
_dep.SomeMethod(i);
}
}
}
Moq Strategy 1 - Verify
var mockSF = new Mock<ISomeInterface>();
var cut = new ClassUnderTest(mockSF.Object);
cut.DoWork();
mockSF.Verify(mockInt => mockInt.SomeMethod(It.Is<int>(i => i == 12345)),
Times.Once());
mockSF.Verify(mockInt => mockInt.SomeMethod(It.Is<int>(i => i == -1)),
Times.Never());
Moq Strategy 2 - Callback
var mockSF = new Mock<ISomeInterface>();
var cut = new ClassUnderTest(mockSF.Object);
bool isGoodValueAlreadyUsed = false;
mockSF.Setup(mockInt => mockInt.SomeMethod(It.Is<int>(i => i == 12345)))
.Callback(() =>
{
if (isGoodValueAlreadyUsed)
{
throw new InvalidOperationException();
}
isGoodValueAlreadyUsed = true;
});
mockSF.Setup(mockInt => mockInt.SomeMethod(It.Is<int>(i => i == -1)))
.Callback(() =>
{ throw new InvalidOperationException(); });
cut.DoWork();
Assert.IsTrue(isGoodValueAlreadyUsed);
Usually when such a limitation is reached, I would reconsider my design (no offense, I see your rep). Looks like the method under test does too much work, which is violation of the single responsibility principle. It first generates a large list of items, and then verifies a worker is called for each one of them, while also verifying that the sequence contains the right elements.
I'd split the functionality into a sequence generator, and verify that the sequence has the right elements, and another method which acts on the sequence, and verify that it executes the worker for each element:
namespace StackOverflowExample.Moq
{
public interface ISequenceGenerator
{
IEnumerable<int> GetSequence();
}
public class SequenceGenrator : ISequenceGenerator
{
public IEnumerable<int> GetSequence()
{
var list = new List<int>();
for (var i = 0; i < 1000000; i++) // Large number of calls to dep
{
list.Add(i);
}
return list;
}
}
public interface ISomeInterface
{
void SomeMethod(int someValue);
}
public class ClassUnderTest
{
private readonly ISequenceGenerator _generator;
private readonly ISomeInterface _dep;
public ClassUnderTest(ISomeInterface dep, ISequenceGenerator generator)
{
_dep = dep;
_generator = generator;
}
public void DoWork()
{
foreach (var i in _generator.GetSequence())
{
_dep.SomeMethod(i);
}
}
}
[TestFixture]
public class LargeSequence
{
[Test]
public void SequenceGenerator_should_()
{
//arrange
var generator = new SequenceGenrator();
//act
var list = generator.GetSequence();
//assert
list.Should().Not.Contain(-1);
Executing.This(() => list.Single(i => i == 12345)).Should().NotThrow();
//any other assertions
}
[Test]
public void DoWork_should_perform_action_on_each_element_from_generator()
{
//arrange
var items = new List<int> {1, 2, 3}; //can use autofixture to generate random lists
var generator = Mock.Of<ISequenceGenerator>(g => g.GetSequence() == items);
var mockSF = new Mock<ISomeInterface>();
var classUnderTest = new ClassUnderTest(mockSF.Object, generator);
//act
classUnderTest.DoWork();
//assert
foreach (var item in items)
{
mockSF.Verify(c=>c.SomeMethod(item), Times.Once());
}
}
}
}
EDIT:
Different approaches can be mixed to define a specific expectations, incl. When(), the obsoleted AtMost(), MockBehavior.Strict, Callback, etc.
Again, Moq is not designed to work on large sets, so there is performance penalty. You are still better off using another measures to verify what data will be passed to the mock.
For the example in the OP, here is a simplified setup:
var mockSF = new Mock<ISomeInterface>(MockBehavior.Strict);
var cnt = 0;
mockSF.Setup(m => m.SomeMethod(It.Is<int>(i => i != -1)));
mockSF.Setup(m => m.SomeMethod(It.Is<int>(i => i == 12345))).Callback(() =>cnt++).AtMostOnce();
This will throw for -1, for more than one invocation with 12, and assertion can be made on cnt != 0.