I have the following FluentValidation code which I need to change so that the validation calls the IsUniqueCode function and also passes the currentID parameter which is the id of the Language object been validated.
public class LanguageValidator : AbstractValidator<Language>
{
public LanguageValidator()
{
RuleFor(x => x.Code).NotEmpty().WithMessage("Language code is required").Length(0, 100);
RuleFor(x => x.Code).Must(IsUniqueCode).WithMessage("Language code provided already exists");
}
private bool IsUniqueCode(string code, int currentID)
{
var _db = new MyDbContext();
var language = _db.Languages.SingleOrDefault(x => x.Code == code);
if (language== null) return true;
return (language.LanguageId != currentID);
}
}
This is so that the second time I save the object it doesn't fail the validation that the Language code provided already exists.
The above code doesn't compile because of
RuleFor(x => x.Code)
.Must(**IsUniqueCode**)
.WithMessage("Language code provided already exists");
Related
I recently started learning Unit Testing and now have the requirement write unit tests using Xunit and Moq for dot net core application.
I can write some very basic but when it comes to write them for complex classes , I am kind of stuck.
Below is the class I will be writing tests for.
public class AgeCategoryRequestHandler : IInventoryRequestHandler<InventoryRequest, HandlerResult>
{
private readonly IRepositoryResolver _repositoryResolver;
Hotels.HBSI.Logging.ILogger logger;
public AgeCategoryRequestHandler(IRepositoryResolver repositoryResolver, Hotels.HBSI.Logging.ILogger iLogger)
{
_repositoryResolver = repositoryResolver;
logger = iLogger;
}
public async Task<HandlerResult> Run(InventoryRequest inventoryRequest)
{
var result = await ProcessRequest(inventoryRequest);
return CreateResponse(inventoryRequest, result);
}
private async Task<int> ProcessRequest(InventoryRequest inventoryRequest)
{
logger.Info("AgeCategory requesthandler processrequest start");
var repository = _repositoryResolver.ResolveEstabAgeCategory();
if (repository is not null)
{
return await repository.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories)
.ConfigureAwait(false);
}
logger.Info("AgeCategory requesthandler processrequest complete");
return InernalError.reponotfound;
}
public HandlerResult CreateResponse(InventoryRequest inventoryRequest, int resultCount)
{
var requestCount = inventoryRequest.EstabAgeCategories.Count;
var handlerResult = new HandlerResult() { Id = RequestHandlerEnum.AgeCategrory.ToInt() };
if (requestCount > 0 && resultCount < requestCount)
{
handlerResult.IsSuccess = false;
handlerResult.ErrorCode = OTAErrorType.InvalidAgeCategory.ToInt();
}
else if (requestCount > 0 || requestCount == resultCount)
{
handlerResult.IsSuccess = true;
handlerResult.ErrorCode = 0;
}
return handlerResult;
}
}
Just to start , IRepositoryResolver and ILogger are in the constructor so I have created mock for these but unable to go beyond that as I am still in initial phase of learning.
Could someone explain me the steps/approach to accomplish this?.
Edit : What I have done so far is below ( can't figure out what are the things to be done and where to start or write )
Edit 2 : Did some more modifications to my test code , can someone comment if I am in right direction ? what else can I test ?
public class AgeCategoryRequestHandlerTest
{
private AgeCategoryRequestHandler _ageCategoryRequestHandler;
private readonly Mock<AgeCategoryRequestHandler> _ageCategory = new Mock<AgeCategoryRequestHandler>();
private readonly Mock<Hotels.HBSI.Logging.ILogger> _mockLogger = new Mock<Hotels.HBSI.Logging.ILogger>();
private readonly Mock<IRepositoryResolver> _mockRepositoryResolver = new Mock<IRepositoryResolver>();
public AgeCategoryRequestHandlerTest()
{
_ageCategoryRequestHandler = new AgeCategoryRequestHandler(_mockRepositoryResolver.Object, _mockLogger.Object);
}
[Fact]
public async void Testtt()
{
var fixture = new Fixture();
var inventory = fixture.Create<InventoryRequest>();
var hndlr = fixture.Create<HandlerResult>();
hndlr.ErrorCode = 0;
int resultCount = 3;
await _ageCategoryRequestHandler.Run(inventory);
HandlerResult response = _ageCategoryRequestHandler.CreateResponse(inventory, resultCount);
Assert.Equal(hndlr.ErrorCode, response.ErrorCode);
}
Tried running Chris B suggested code , was getting type conversion error EstabAgeCategories = new List<int>
Now I have used fixture for creating automatic objects and did some assert values. Below is the code sample
var fixture = new Fixture();
var inventoryRequest = fixture.Create<InventoryRequest>();
_mockRepository
.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories))
.ReturnsAsync(6);
_mockRepositoryResolver
.Setup(x => x.ResolveEstabAgeCategory())
.Returns(_mockRepository.Object);
// act
var result = await _ageCategoryRequestHandler.Run(inventoryRequest);
// assert
_mockRepository
.Verify(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories), Times.Once);
Assert.True(result.Id == 6);
Assert.True(result.ErrorCode == 0);
Assert.True(result.IsSuccess);
From the unit test code you've posted, it looks like you are getting confused on what to test.
Look at your class and identify your "public" interface i.e. what methods can be called from other parts of your code. You should really only test public methods. Private methods are usually tested via public methods.
Looking at AgeCategoryRequestHandler, you have two public methods - Run and CreateResponse. I would question whether CreateResponse needs to be public but we'll leave it for now. For each of these methods, you want to be asserting that the returned value is what you expect given the input value.
private AgeCategoryRequestHandler _ageCategoryRequestHandler;
// Not needed
private readonly Mock<AgeCategoryRequestHandler> _ageCategory = new Mock<AgeCategoryRequestHandler>();
private readonly Mock<Hotels.HBSI.Logging.ILogger> _mockLogger = new Mock<Hotels.HBSI.Logging.ILogger>();
private readonly Mock<IRepositoryResolver> _mockRepositoryResolver = new Mock<IRepositoryResolver>();
public AgeCategoryRequestHandlerTest()
{
_ageCategoryRequestHandler = new AgeCategoryRequestHandler(_mockRepositoryResolver.Object, _mockLogger.Object);
}
The set up of the unit test is going the right way - you have created mocks for your dependencies but I see you have created a mock for the class you are trying to test - this is not needed and can be removed. You want to be testing the actual class itself which you are initializing in the constructor.
public async Task<HandlerResult> Run(InventoryRequest inventoryRequest)
{
var result = await ProcessRequest(inventoryRequest);
return CreateResponse(inventoryRequest, result);
}
private async Task<int> ProcessRequest(InventoryRequest inventoryRequest)
{
_logger.LogInformation("AgeCategory requesthandler processrequest start");
var repository = _repositoryResolver.ResolveEstabAgeCategory();
if (repository != null)
{
return await repository.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories).ConfigureAwait(false);
}
_logger.LogInformation("AgeCategory requesthandler processrequest complete");
return 0;
}
We can test the public Run method by looking at the method and seeing what it is going to do when executed. Firstly, it's going to call a private method ProcessRequest. Inside ProcessRequest, the IRepositoryResolver dependency is going to be used. This means we need to "set up" this dependency in our unit test to satisfy the if (repository != null) condition.
I assume the IRepositoryResolver returns another interface (?) - something like:
public interface IRepository
{
Task<int> InsertUpdateEstabAgeCategoryDetail(List<int> x);
}
So in your unit test, you need to create a mock for the repository being returned from IRepositoryResolver:
private readonly Mock<IRepository> _mockRepository = new Mock<IRepository>();
Then, you need to set up the mock IRepositoryResolver to return the mock repository above:
_mockRepositoryResolver
.Setup(x => x.ResolveEstabAgeCategory())
.Returns(_mockRepository.Object);
This is to satisfy the if (repository != null) condition.
_mockRepository
.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories))
.ReturnsAsync(6);
Next, you need to set up the InsertUpdateEstabAgeCategoryDetail() method on the mock repository to return a value. This value is being returned by ProcessRequest() and then used to call CreateResponse(inventoryRequest, result) as the result parameter.
if (requestCount > 0 && resultCount < requestCount)
{
handlerResult.IsSuccess = false;
handlerResult.ErrorCode = (int)OTAErrorType.InvalidAgeCategory;
}
else if (requestCount > 0 || requestCount == resultCount)
{
handlerResult.IsSuccess = true;
handlerResult.ErrorCode = 0;
}
Now you can look at the CreateResponse method and by setting different values for inventoryRequest.EstabAgeCategories and setting up the mock _mockRepository.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories)).ReturnsAsync(6); to return different values, you can satisfy the different paths through the if statement.
CreateResponse is returning an instance of HandlerResult which in turn is being returned by Task<HandlerResult> Run. This is the returned object you want to make assertions on.
One of the unit test cases might look like this (I have not tested it myself):
[Fact]
public async Task GivenInventoryRequest_WhenRun_ThenHandlerResultReturned()
{
// arrange
var inventoryRequest = new InventoryRequest
{
EstabAgeCategories = new List<int>
{
1, 2, 3, 4, 5
}
};
_mockRepository
.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories))
.ReturnsAsync(6);
_mockRepositoryResolver
.Setup(x => x.ResolveEstabAgeCategory())
.Returns(_mockRepository.Object);
// act
var result = await _ageCategoryRequestHandler.Run(inventoryRequest);
// assert
_mockRepository
.Verify(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories), Times.Once);
Assert.True(result.Id == 0);
Assert.True(result.ErrorCode == 0);
Assert.False(result.IsSuccess);
}
I want to start using FakeItEasy for testing queries.
The tests I want to write should check if entities are returned on HttpGet calls (get all and get by Id)
The Controller:
public class ToDoController : ControllerBase
{
private readonly IMediator _mediator;
public ToDoController(IMediator mediator) =>
_mediator = mediator;
[HttpGet]
[Produces("application/json")]
[ProducesResponseType(typeof(IEnumerable<ToDoItem>), (int)HttpStatusCode.OK)]
public async Task<ActionResult<IEnumerable<ToDoItem>>> Get()
{
var result = await _mediator.Send(new ToDoItemsQuery(new
AllToDoItems())).ConfigureAwait(false);
if (result != null && result.Any())
{
return result.ToList();
}
throw new InvalidOperationException("TODO: error handling");
}
[HttpGet]
[Route("{id}")]
[Produces("application/json")]
[ProducesResponseType(typeof(ToDoItem), (int)HttpStatusCode.OK)]
public async Task<ActionResult<ToDoItem>> GetById(int itemId)
{
var result = await _mediator
.Send(new ToDoItemsQuery(new ToDoItemById(itemId)))
.ConfigureAwait(false);
if (result != null && result.Any())
{
return result.FirstOrDefault();
}
throw new InvalidOperationException("TODO: error handling");
}
}
}
The TestClass:
public class ToDoItemControllerTests : ControllerTestBase
{
private IMediator _mediator;
private ToDoController _sut;
public ToDoItemControllerTests()
{
_mediator = A.Fake<IMediator>();
_sut = new ToDoController(_mediator);
}
[TestMethod]
public async Task GetAllItemsAsync_SuccessTest()
{
A.CallTo(() => _mediator.Send(A<AllToDoItems>._,
A<CancellationToken>._)).Returns(A.CollectionOfFake<ToDoItem>(10));
var result = await _sut.Get();
Assert.IsNotNull(result);
A.CallTo(() => _mediator).MustHaveHappened();
}
[TestMethod]
public async Task GetItemByIdAsync_SuccessTest()
{
// Arrange
int itemId = 2;
var commandResult =
new List<ToDoItem>
{
new ToDoItem
{
Id = itemId
};
}
A.CallTo(() => MediatR.Send(A<ToDoItemById>._, A<CancellationToken>._)).Returns(commandResult);
// Act
var result = await _sut.GetById(itemId);
// Assert
Assert.IsNotNull(result);
A.CallTo(() => MediatR.Send(A<ToDoItemById>._, A<CancellationToken>._)).MustHaveHappened();
}
}
So in the first test I set up A.CallTo the interface IMediatR to return 10 ToDoItems.
During debug I see the _sut.Get() enter the controller, entering the correct method/api call.
The _mediator.Send() in the controller returns a Fake IEnumerable (not the 10 items i set up in the first Call.To in the testmethod, but an enumeration that yields no results).
Because of the result.Any() being false, the controller throws an InvalidOperationException
And I cannot even Assert the result.IsNotNull()
The second test I want to Test If 1 item is returned upon calling the API.
I set up (a) an itemId of type int for parameter,
(b) A mocked(?) List with 1 Item from the setup with the itemId and
(c) a call to the mediatR should return the mocked Listfrom (b)
I make the call from the test, in debug I see the call await _mediator.Sent() returning
A Fake Ienumerable of ToDoItem, result is not null, but because result.Any() is false,
the item doesn't get returned, and I get another InvalidOperationException
I feel like I'm missing something in the setup of the tests..
A Fake database Interface?
I don't want to chance my controller and make the if less restrictive, just so my test would pass
EDIT:
Even if I change the if condition to removing the Any condition
and I see the test entering the controller, returning "First Or Default" of the result,
The test fails on A Call To Must Have Happened.
Expected to find it once or more but no calls were made to the fake object.
This I really don't get, i actually see him making the call?!
I've browsed GitHub to find examples but the closest I found was Entities with methods, with those methods being defined in an interface. This is not the case here
Seeing as the official documentation doesn't make me any wiser I turn to SO <3
Thanks in advance!
In the first test, you configure the call to Send with an argument of type AllToDoItems. But in the controller, you actually call Send with a TodoItemsQuery. So the call doesn't match, and the default (unconfigured) behavior, which is to return a fake IEnumerable, applies. You need to configure the call like this:
A.CallTo(() => _mediator.Send(A<TodoItemsQuery>._,
A<CancellationToken>._)).Returns(A.CollectionOfFake<ToDoItem>(10));
In the second test, the problem is the same, with ToDoItemById instead of AllToDoItems
I recently upgraded an application I am working on from Cocktail 1.4 to Cocktail 2.6 (Punch). I have adjusted my bootstrapper class for the wpf project which now loads with no issues. However, on my WCF / Web projects, I am receiving a runtime exception with the following error when attempting to call Composition.GetInstance:
"You must first set a valid CompositionProvider by using Composition.SetProvider."
After digging into the issue a bit, it appears the composition container is automatically configured when your bootstrapper inherits from CocktailMefBootstrapper. I currently do not have bootstrapper classes at all for non-wpf projects. Prior to the upgrade, all I had to do was call the configure method on the Composition class to configure the composition container, but it appears that it has been deprecated:
Composition.Configure();
I noticed that you can also call Composition.SetProvider(), however I am a little unsure on how to satisfy the method signature exactly. The DevForce Punch documentation states that the generic type for the bootstrapper class should be a viewmodel, and there are no views / view models in a service project. This leaves me in limbo on what to do as I don't want to rip cocktail out of these WCF projects. Is there still a way to use Cocktail's composition container without a bootstrapper for a project in Cocktail (Punch) 2.6?
UPDATE
I found this on the DevForce forums. So it appears that I ought to learn how to configure a multi threaded ICompositionProvider and call Composition.SetProvider() as mentioned above. Any recommended articles to achieving this?
After digging through Punch's source code and looking at Ideablade's MefCompositionContainer, which implements ICompositionProvider, I created my own thread safe implementation of ICompositionProvider. Below is the code I used. Basically, it's the same code for Ideablade's MefCompositionContainer which can be found here in their repository. The only change is that I am passing a bool flag of true into the CompositionContainer's constructor. MSDN lists the pros and cons of making the container thread safe
internal partial class ThreadSafeCompositionProvider : ICompositionProvider
{
static ThreadSafeCompositionProvider()
{
CompositionHost.IgnorePatterns.Add("Caliburn.Micro*");
CompositionHost.IgnorePatterns.Add("Windows.UI.Interactivity*");
CompositionHost.IgnorePatterns.Add("Cocktail.Utils*");
CompositionHost.IgnorePatterns.Add("Cocktail.Compat*");
CompositionHost.IgnorePatterns.Add("Cocktail.dll");
CompositionHost.IgnorePatterns.Add("Cocktail.SL.dll");
CompositionHost.IgnorePatterns.Add("Cocktail.WinRT.dll");
}
public IEnumerable<Assembly> GetProbeAssemblies()
{
IEnumerable<Assembly> probeAssemblies = CompositionHost.Instance.ProbeAssemblies;
var t = GetType();
// Add Cocktail assembly
probeAssemblies = probeAssemblies.Concat(GetType().GetAssembly());
return probeAssemblies.Distinct(x => x);
}
private List<Assembly> _probeAssemblies;
private AggregateCatalog _defaultCatalog;
private ComposablePartCatalog _catalog;
private CompositionContainer _container;
public ComposablePartCatalog Catalog
{
get { return _catalog ?? DefaultCatalog; }
}
public ComposablePartCatalog DefaultCatalog
{
get
{
if (_defaultCatalog == null)
{
_probeAssemblies = GetProbeAssemblies().ToList();
var mainCatalog = new AggregateCatalog(_probeAssemblies.Select(x => new AssemblyCatalog(x)));
_defaultCatalog = new AggregateCatalog(mainCatalog);
CompositionHost.Recomposed += new EventHandler<RecomposedEventArgs>(OnRecomposed)
.MakeWeak(x => CompositionHost.Recomposed -= x);
}
return _defaultCatalog;
}
}
internal void OnRecomposed(object sender, RecomposedEventArgs args)
{
if (args.HasError) return;
var newAssemblies = GetProbeAssemblies()
.Where(x => !_probeAssemblies.Contains(x))
.ToList();
if (newAssemblies.Any())
{
var catalog = new AggregateCatalog(newAssemblies.Select(x => new AssemblyCatalog(x)));
_defaultCatalog.Catalogs.Add(catalog);
_probeAssemblies.AddRange(newAssemblies);
}
// Notify clients of the recomposition
var handlers = Recomposed;
if (handlers != null)
handlers(sender, args);
}
public CompositionContainer Container
{
get { return _container ?? (_container = new CompositionContainer(Catalog, true)); }
}
public Lazy<T> GetInstance<T>() where T : class
{
var exports = GetExportsCore(typeof(T), null).ToList();
if (!exports.Any())
throw new Exception(string.Format("Could Not Locate Any Instances Of Contract", typeof(T).FullName));
return new Lazy<T>(() => (T)exports.First().Value);
}
public T TryGetInstance<T>() where T : class
{
if (!IsTypeRegistered<T>())
return null;
return GetInstance<T>().Value;
}
public IEnumerable<T> GetInstances<T>() where T : class
{
var exports = GetExportsCore(typeof(T), null);
return exports.Select(x => (T)x.Value);
}
public Lazy<object> GetInstance(Type serviceType, string contractName)
{
var exports = GetExportsCore(serviceType, contractName).ToList();
if (!exports.Any())
throw new Exception(string.Format("Could Not Locate Any Instances Of Contract",
serviceType != null ? serviceType.ToString() : contractName));
return new Lazy<object>(() => exports.First().Value);
}
public object TryGetInstance(Type serviceType, string contractName)
{
var exports = GetExportsCore(serviceType, contractName).ToList();
if (!exports.Any())
return null;
return exports.First().Value;
}
public IEnumerable<object> GetInstances(Type serviceType, string contractName)
{
var exports = GetExportsCore(serviceType, contractName);
return exports.Select(x => x.Value);
}
public ICompositionFactory<T> GetInstanceFactory<T>() where T : class
{
var factory = new ThreadSafeCompositionFactory<T>();
Container.SatisfyImportsOnce(factory);
if (factory.ExportFactory == null)
throw new CompositionException(string.Format("No export found.", typeof(T)));
return factory;
}
public ICompositionFactory<T> TryGetInstanceFactory<T>() where T : class
{
var factory = new ThreadSafeCompositionFactory<T>();
Container.SatisfyImportsOnce(factory);
if (factory.ExportFactory == null)
return null;
return factory;
}
public void BuildUp(object instance)
{
// Skip if in design mode.
if (DesignTime.InDesignMode())
return;
Container.SatisfyImportsOnce(instance);
}
public bool IsRecomposing { get; internal set; }
public event EventHandler<RecomposedEventArgs> Recomposed;
internal bool IsTypeRegistered<T>() where T : class
{
return Container.GetExports<T>().Any();
}
public void Configure(CompositionBatch compositionBatch = null, ComposablePartCatalog catalog = null)
{
_catalog = catalog;
var batch = compositionBatch ?? new CompositionBatch();
if (!IsTypeRegistered<IEventAggregator>())
batch.AddExportedValue<IEventAggregator>(new EventAggregator());
Compose(batch);
}
public void Compose(CompositionBatch compositionBatch)
{
if (compositionBatch == null)
throw new ArgumentNullException("compositionBatch");
Container.Compose(compositionBatch);
}
private IEnumerable<Lazy<object>> GetExportsCore(Type serviceType, string key)
{
return Container.GetExports(serviceType, null, key);
}
}
After setting up that class, I added a configuration during startup to instantiate my new thread safe composition provider and to set it as the provider for Punch's Composition class:
if (createThreadSafeCompositionContainer)
{
var threadSafeContainer = new ThreadSafeCompositionProvider();
Composition.SetProvider(threadSafeContainer);
}
Seems to be working like a charm!
public class GetDatasourceDependencies : BaseProcessor
{
/// <summary>
/// The process.
/// </summary>
/// <param name="context">
/// The context.
/// </param>
public override void Process(GetDependenciesArgs context)
{
Assert.IsNotNull(context.IndexedItem, "indexed item");
Assert.IsNotNull(context.Dependencies, "dependencies");
Item item = (context.IndexedItem as SitecoreIndexableItem);
if (item != null)
{
var layoutLinks = Globals.LinkDatabase.GetReferrers(item, FieldIDs.LayoutField);
var sourceUris = layoutLinks.Select(l => l.GetSourceItem().Uri).Where(uri => uri != null && uri != item.Uri).Distinct();
context.Dependencies.AddRange(sourceUris.Select(x => (SitecoreItemUniqueId)x));
}
}
}
How do I write a test with typock for this. I am very new to typemock and have written something like this. I understand that i need to mock the args and context but as the method is returning nothing back, how do i test it.
My test should be success only if the context.dependents have some values.
[Test]
public void GetIndexingDependencies_Calls()
{
var indexable = Isolate.Fake.Instance<IIndexable>();
var fake = Isolate.Fake.Instance<GetDependenciesArgs>();
var context = Isolate.Fake.Instance<GetDatasourceDependencies>();
var obj = new GetDatasourceDependencies();
Isolate.Verify.WasCalledWithAnyArguments(() => context.Process(fake));
Isolate.WhenCalled(() => fake.IndexedItem).WillReturn(indexable);
//Isolate.WhenCalled(() => fake.Dependencies.Count).WillReturn(2);
}
Disclaimer, I work at Typemock.
You can use a real collection for context.Dependencies and assert that some items are actually added.
To achieve this you should replace the collection that Globals returns and make sure that linq can process it as you expect (I just returned the same collection from the linq query for the sake of the example).
Your test should look something like this:
public void GetIndexingDependencies_Calls()
{
//Arrange
var fakeContext = Isolate.Fake.Instance<GetDependenciesArgs>();
fakeContext.Dependencies = new List<SitecoreItemUniqueId>();
var itemList = new List<SomeItem> { new SomeItem(), new SomeItem() };
Isolate.WhenCalled(() => Globals.LinkDatabase.GetReferrers(null, null)).WillReturn(itemList);
Isolate.WhenCalled(() => itemList.Select(l => l.GetSourceItem().Uri).Where(uri => true).Distinct()).WillReturn(itemList);
//ACT
var underTest = new GetDatasourceDependencies();
underTest.Process(fakeContext);
//ASSERT
Assert.AreEqual(2, fakeContext.Dependencies.Count);
}
Some more points:
Don't fake whatever you're testing, in this case it's GetDatasourceDependencies. If it's faked it will not really be called and not be tested.
Don't write asserts\verify before the executing the code that you're trying to test, in this case context.Process(fake) wasn't called before verify.
I want to substitute object to return sequence of different objects.
For example:
var http = Substitute.For<IHttp>();
http.GetResponse(Arg.Any<string>()).Returns(resourceString, resourceString2);
http.GetResponse(Arg.Any<string>()).Returns(x => { throw new Exception(); });
will return resourceString then resourceString2 then exception.
Or something like this:
var http = Substitute.For<IHttp>();
http.GetResponse(Arg.Any<string>()).Returns(resourceString, x => { throw new Exception(); }, resourceString2);
will return resourceString then exception then resourceString2.
How can I do that?
This is now a supported feature in NSubstitute with a very friendly interface.
It would be something like...
var http = Substitute.For<IHttp>();
http.GetResponse(Arg.Any<string>()).Returns(
x => resourceString,
x => resourceString2,
x => { throw new Exception(); }
);
Documentation can be found here
This answer is outdated — NSubstitute has direct support for this now. Please see #dangerdex's answer to this question for more information.
The multiple returns syntax in NSubstitute only supports values. To also throw exceptions you'll need to pass a function to Returns, and implement the required logic yourself (e.g. Returns(x => NextValue())).
There is a related example for Moq sequences on Haacked's blog using a queue. You can do a similar thing with NSubstitute (example code only, use at your own risk :)):
public interface IFoo { int Bar(); }
[Test]
public void Example() {
var results = new Results<int>(1)
.Then(2)
.Then(3)
.Then(() => { throw new Exception("oops"); });
var sub = Substitute.For<IFoo>();
sub.Bar().Returns(x => results.Next());
Assert.AreEqual(1, sub.Bar());
Assert.AreEqual(2, sub.Bar());
Assert.AreEqual(3, sub.Bar());
Assert.Throws<Exception>(() => sub.Bar());
}
public class Results<T> {
private readonly Queue<Func<T>> values = new Queue<Func<T>>();
public Results(T result) { values.Enqueue(() => result); }
public Results<T> Then(T value) { return Then(() => value); }
public Results<T> Then(Func<T> value) {
values.Enqueue(value);
return this;
}
public T Next() { return values.Dequeue()(); }
}
Hope this helps.
Here's an example that does everything inline without an extra class. If you were doing this a lot I would probably go with the separate class option.
[Test]
public void WhenSomethingHappens()
{
var something = Substitute.For<ISomething>();
int callCount = 0;
something.SomeCall().Returns(1, 2);
something.When(x => x.SomeCall()).Do(obj => { if (++callCount == 3) throw new Exception("Problem!"); });
Assert.AreEqual(1, something.SomeCall());
Assert.AreEqual(2, something.SomeCall());
Assert.Throws<Exception>(() => something.SomeCall());
}
public interface ISomething
{
int SomeCall();
}
Another example with out parameter.
Moreover it is usueful for some scenarios when function is called periodically in separated thread. We can simulate/mock each call differently.
List<AnyClass> items = new List<AnyClass>();
mockIService.TryDoSth(out response).ReturnsForAnyArgs(p =>
{
p[0] = items;
return true;
},
p =>
{
p[0] = items;
return true;
}, p =>
{
throw new Exception("Problem!");
});
bool TryDoSth(out List result);