I recently started tdd, but my mocking knowledge is incomplete. I know the basics but, Tests for some methods which were written without thinking tdd, really confuse me.
Here is what I am trying to test
public int GetThirdPartyUserId(int serviceTypeId, string accessToken)
{
ThirdPartyRequestDetail requestDetail = GetThirdPartyRequestDetails(serviceType, accessToken);
IHttwrapConfiguration configuration = new HttwrapConfiguration(requestDetail.BaseUrl);
IHttwrapClient httwrap = new HttwrapClient(configuration);
Task<IHttwrapResponse<OpenAuthUserResponse>> response = httwrap.GetAsync<OpenAuthUserResponse>(requestDetail.PathAndQuery);
try
{
if (response.Result.Data != null && response.Status != TaskStatus.Faulted)
{
//Do something
}
else
{
//WANT TO TEST HERE
}
}
}
Here is my test method
private Mock<IHttwrapClient> _httpwrap;
public void httprwapTest()
{
string accessToken = "invalid";
int thirdPartySiteId = (int)ThirdPartyServiceType.GooglePlus;
string requestPath = _fixture.Create<string>();
_httpwrap.Setup(item => item.GetAsync(requestPath)).Returns(Task.FromResult(new HttwrapResponse(HttpStatusCode.BadRequest, "body")));
OpenAuthUserResponse response = _oauthAuthenticator.GetThirdPartyUser(thirdPartySiteId, accessToken);
Assert.AreEqual(response.Error, OauthAuthenticatorErrorType.RequestFaulted);
}
What I tried to do is below but it didn't get triggered.
_httpwrap.Setup(item => item.GetAsync(requestPath)).Returns(Task.FromResult(new HttwrapResponse(HttpStatusCode.BadRequest, "body")));
How I can test my classes behaviour when httpwrap gives me a badrequest response code?
In it's current form, you can't use a conventional mocking framework to help with your test. In order for the Mocking to work, you have to Setup the same mock that you're using in your production code. Currently there's no connection between the mock you're creating in your test and the IHttpwrapClient that your method under test depends on.
The first step you would need to do take is to move the creation of the HttpwrapClient outside of the method that you want to test. You then need to make it available to the code, via it's interface, in a way that you can later supply it from your test.
There are three common ways of supplying the interface.
Inject it into the constructor for your class
Inject it through a property on your class
Pass it as an argument to the function
Generally constructor injection is preferred over property injection, but it's largely up to you which approach is going to work best (they each have positives and negatives) and what makes most sense for the data that you're injecting.
You would then create the Mock of your interface and inject it into your code as appropriate.
As far as your production code goes, you're still going to need to create an instance of your concrete class. You can either do this directly when calling your class, or via something like a factory, or by using an IoC container, like Castle Winsor or Ninject (there are several others).
Related
I am having troubles when testing a controller, because there are some lines at my Startup that are null when testing, I want to add a condition for run this lines only if it's not testing.
// Desired method that retrieves if testing
if (!this.isTesting())
{
SwaggerConfig.ConfigureServices(services, this.AuthConfiguration, this.ApiMetadata.Version);
}
The correct answer (although of no help): It should not be able to tell so. The application should to everything it does unaware if it is in productino or test.
However to test the application in a simpler setting, you can use fake modules or mock-up modules that are loaded instead of the heavy-weight production modules.
But in order to use that, you have to refactor your solution and use injection for instance.
Some links I found:
Designing with interfaces
Mock Objects
Some more on Mock objects
It really depends on which framework you use for testing. It can be MSTest, NUnit or whatever.
Rule of thumb, is that your application should not know whether it is tested. It means everything should be configured before actual testing through injection of interfaces. Simple example of how tests should be done:
//this service in need of tests. You must test it's methods.
public class ProductionService: IProductionService
{
private readonly IImSomeDependency _dep;
public ImTested(IImSomeDependency dep){ _dep = dep; }
public void PrintStr(string str)
{
Console.WriteLine(_dep.Format(str));
}
}
//this is stub dependency. It contains anything you need for particular test. Be it some data, some request, or just return NULL.
public class TestDependency : IImSomeDependency
{
public string Format(string str)
{
return "TEST:"+str;
}
}
//this is production, here you send SMS, Nuclear missle and everything else which cost you money and resources.
public class ProductionDependency : IImSomeDependency
{
public string Format(string str)
{
return "PROD:"+str;
}
}
When you run tests you configure system like so:
var service = new ProductionService(new TestDependency());
service.PrintStr("Hello world!");
When you run your production code you configure it like so:
var service = new ProductionService(new ProductionDependency());
service.PrintStr("Hello world!");
This way ProductionService is just doing his work, not knowing about what is inside it's dependencies and don't need "is it testing case №431" flag.
Please, do not use test environment flags inside code if possible.
UPDATE:
See #Mario_The_Spoon explanation for better understanding of dependency management.
I want to test my Class, which calls the third Party Webservice. Is it possible to use FakeItEasy for this?
Wenn I try to Fake the Class from Reference.cs (auto generated), UnitTest started and doesn't come back.
Reference.cs(auto generated)
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")]
public partial class ws_AccessoryClient : System.ServiceModel.ClientBase<AccessoryService.ws_Accessory>,
AccessoryService.ws_Accessory
{
public ws_AccessoryClient()
{
}
public ws_AccessoryClient(string endpointConfigurationName) :
base(endpointConfigurationName)
{
}
public AccessoryService.ResponseMessageOf_ListOf_SomeMethodInfo SomeMethod(
AccessoryService.RequestMessageOf_SomeMethod request)
{
return base.Channel.SomeMethod(request);
}
}
Test.cs
[Test]
public void DoBusinessLogicTryTest()
{
var accessoryProxy = A.Fake<ws_AccessoryClient>();
}
As has been mentioned you may not want to do what you are purposing for Unit Testing as this would cause more noise than is necessary for a Unit Test which could used mocked interfaces. However it is a valid approach for integration testing, this would allow you to test that your WCF wiring is working as you expect it. It also allows you to test your application as whole if you are adopting a more behaviour driven style of testing where you want to mock as little as possible.
I use this approach myself for spinning up fake endpoints using NSubstitute which is covered in my blog Hosting a Mock as a WCF service. The main things you need to do is spin up a ServiceHost, give it the endpoint address you want to use, set the context mode to single and provide the mock you want to use as the endpoint.
var serviceHost = new ServiceHost(mock, new[] { baseAddress });
serviceHost.Description.Behaviors
.Find<ServiceDebugBehavior>().IncludeExceptionDetailInFaults = true;
serviceHost.Description.Behaviors
.Find<ServiceBehaviorAttribute>().InstanceContextMode = InstanceContextMode.Single;
serviceHost.AddServiceEndpoint(typeof(TMock), new BasicHttpBinding(), endpointAddress);
One thing that I do in my testing is randomly choose the port that I host the endpoint on and inject the address into my application during testing. That way your tests will be able to run on other machines and build servers without clashing with other ports in use.
After looking at your example you might want to consider using the WCF ChannelFactory to create your client instead of using a concrete proxy client class. The ChannelFactory creates a proxy on the fly using the Interface you provide and allowing you to inject the proxy into its dependencies using the service interface. This would make unit testing easier and give you a more decoupled design.
You cannot (and why would you want to?).
If you want to verify that your class under test makes the call to the service, then wrap the service call in a class who's only job it is to call the service, and define it with an interface.
interface ICallTheService
{
void CallTheService();
}
class ServiceCaller : ICallTheService
{
void CallTheService()
{
// Call the service...
}
}
Then you can fake this class and verify that your class under test invokes the CallTheService operation.
// fake the service caller and pass it into your service
var serviceCaller = A.Fake<ICallTheService>();
// Verify invocation
A.CallTo(() => serviceCaller.CallTheService()).MustHaveHappened();
I want to test the logic in my class, depends on Response from
WCF-Service
This is where I think you're going wrong with separation of concerns. Your test is called DoBusinessLogicTryTest, yet it has a dependency on System.ServiceModel, which is an infrastructure concern. Your business logic should be testable without this dependency. If your class under test needs to behave differently depending on the response, you could do something like this:
interface ICallTheService
{
ServiceResponseModel CallTheService();
}
enum ServiceResponseModel
{
Success,
PartialSuccess,
FailureCondition1,
FailureCondition2,
// etc...
}
Then you can prime the ICallTheService fake to return each of the possible responses and test your class based on this.
A.CallTo(() => serviceCaller.CallTheService()).Returns(ServiceResponseModel.Success);
For Example if some Exceptions (defined in WCF) are handled correct
This is also nothing to do with business logic. The actual handling of exceptions is the responsibility of the ICallTheService implementation. In fact, I would introduce another class for this, whose job it would be to translate the various possible exceptions from System.ServiceModel into your response model. Eg
class WCFErrorResponseTranslator
{
ServiceResponseModel TranslateWCFException (Exception ex)
{
if (ex.GetType() == typeOf(TimeoutException)) { return ServiceResponseModel.TimeOut; }
/// etc
}
}
This behaviour could then be tested in isolation.
I am currently using Simple Injector for the first time. In my .NET project I am running test and mocking data returned from a web service and registering the object to the container like so
_container.Register<IWebServiceOrder>(() => mock.Object, Lifestyle.Transient);
This works fine. But in my tests I want to test the behavior of the system on a second call to the web service that will contain updated data, so the mock object will need to be updated.
By default Simple Injector does not allow Overriding existing registrations but the official website states it is possible to change this behavior like below.
https://simpleinjector.readthedocs.org/en/latest/howto.html#override-existing-registrations
container.Options.AllowOverridingRegistrations = true;
Unfortunately i still get an error when i try to register the object a second time even with the above code.
The container can't be changed after the first call to GetInstance, GetAllInstances and Verify
Any ideas on why this is happening?
Replacing an existing registration after you already worked with the container hardly ever has the behavior you would expect (and this holds for all DI libraries) and that's the reason why the Simple Injector container is locked. This is described in more details here (as #qujck already pointed out).
First of all, if you are writing unit tests, you shouldn't use a container at all. Your unit tests should create the class under test themselves, or you extract this logic to a convenient factory method, such as:
private static MailNotifier CreateMailNotifier(
IDeposit deposit = null, ISendMail mailSender = null, ILog logger = null)
{
return new MailNotifier(
deposit ?? Substitute.For<IDeposit>(),
mailSender ?? Substitute.For<ISendMail>(),
logger ?? Substitute.For<ILog>());
}
This factory method is a variation to the Test Data Builder pattern.
By making use of optional parameters, it allows the unit test to specify only the fake implementation it requires during testing:
public void Notify_WithValidUser_LogsAMessage()
{
// Arrange
var user = new User();
var logger = new FakeLogger();
MailNotifier sut = CreateMailNotifier(logger: logger);
// Act
sut.Notify(user);
// Assert
Assert.AreEqual(expected: 1, actual: logger.LoggedMessages.Count);
}
If you use a container, because creating the class under test by hand is too cumbersome, it indicates a problem in your class under test (most likely a Single Responsibility Principle violation). Prevent using tools to work around problems in your design; your code is speaking to you.
For integration tests however, it is much more usual to use the container, but in that case you should simply create a new container for each integration test. This way you can add or replace the IWebServiceOrder without any problem.
I've been given a task of creating a restful web service with JSON formating using WCF with the below methods using TDD approach which should store the Product as a text file on disk:
CreateProduct(Product product)
GetAProduct(int productId)
URI Templates:
POST to /MyService/Product
GET to /MyService/Product/{productId}
Creating the service and its web methods are the easy part but
How would you approach this task with TDD? You should create a test before creating the SUT codes.
The rules of unit tests say they should also be independent and repeatable.
I have a number of confusions and issues as below:
1) Should I write my unit tests against the actual service implementation by adding a reference to it or against the urls of the service (in which case I'd have to host and run the service)? Or both?
2)
I was thinking one approach could be just creating one test method inside which I create a product, call the CreateProduct() method, then calling the GetAProduct() method and asserting that the product which was sent is the one that I have received. On TearDown() event I just remove the product which was created.
But the issues I have with the above is that
It tests more than one feature so it's not really a unit test.
It doesn't check whether the data was stored on file correctly
Is it TDD?
If I create a separate unit test for each web method then for example for calling GetAProduct() web method, I'd have to put some test data stored physically on the server since it can't rely on the CreateProduct() unit tests. They should be able to run independently.
Please advice.
Thanks,
I'd suggest not worrying about the web service end points and focus on behavior of the system. For the sake of this discussion I'll drop all technical jargon and talk about what I see as the core business problem you're trying to solve: Creating a Product Catalog.
In order to do so, start by thinking through what a product catalog does, not the technical details about how to do it. Use that as your starting points for your tests.
public class ProductCatalogTest
{
[Test]
public void allowsNewProductsToBeAdded() {}
[Test]
public void allowsUpdatesToExistingProducts() {}
[Test]
public void allowsFindingSpecificProductsUsingSku () {}
}
I won't go into detail about how to implement the tests and production code here, but this is a starting point. Once you've got the ProductCatalog production class worked out, you can turn your attention to the technical details like making a web service and marshaling your JSON.
I'm not a .NET guy, so this will be largely pseudocode, but it probably winds up looking something like this.
public class ProductCatalogServiceTest
{
[Test]
public void acceptsSkuAsParameterOnGetRequest()
{
var mockCatalog = new MockProductCatalog(); // Hand rolled mock here.
var catalogService = new ProductCatalogService(mockCatalog);
catalogService.find("some-sku-from-url")
mockCatalog.assertFindWasCalledWith("some-sku-from-url");
}
[Test]
public void returnsJsonFromGetRequest()
{
var mockCatalog = new MockProductCatalog(); // Hand rolled mock here.
mockCatalog.findShouldReturn(new Product("some-sku-from-url"));
var mockResponse = new MockHttpResponse(); // Hand rolled mock here.
var catalogService = new ProductCatalogService(mockCatalog, mockResponse);
catalogService.find("some-sku-from-url")
mockCatalog.assertWriteWasCalledWith("{ 'sku': 'some-sku-from-url' }");
}
}
You've now tested end to end, and test drove the whole thing. I personally would test drive the business logic contained in ProductCatalog and likely skip testing the marshaling as it's likely to all be done by frameworks anyway and it takes little code to tie the controllers into the product catalog. Your mileage may vary.
Finally, while test driving the catalog, I would expect the code to be split into multiple classes and mocking comes into play there so they would be unit tested, not a large integration test. Again, that's a topic for another day.
Hope that helps!
Brandon
Well to answer your question what I would do is to write the test calling the rest service and use something like Rhino Mocks to arrange (i.e setup an expectation for the call), act (actually run the code which calls the unit to be tested and assert that you get back what you expect. You could mock out the expected results of the rest call. An actual test of the rest service from front to back would be an integration test not a unit test.
So to be clearer the unit test you need to write is a test around what actually calls the rest web service in the business logic...
Like this is your proposed implementation (lets pretend this hasn't even been written)
public class SomeClass
{
private IWebServiceProxy proxy;
public SomeClass(IWebServiceProxy proxy)
{
this.proxy = proxy;
}
public void PostTheProduct()
{
proxy.Post("/MyService/Product");
}
public void REstGetCall()
{
proxy.Get("/MyService/Product/{productId}");
}
}
This is one of the tests you might consider writing.
[TestFixture]
public class TestingOurCalls()
{
[Test]
public Void TestTheProductCall()
{
var webServiceProxy = MockRepository.GenerateMock<IWebServiceProxy>();
SomeClass someClass = new SomeClass(webServiceProxy);
webServiceProxy.Expect(p=>p.Post("/MyService/Product"));
someClass.PostTheProduct(Arg<string>.Is.Anything());
webServiceProxy.VerifyAllExpectations();
}
}
Why won't this test method work? I keep getting requires a return value or an exception to throw.
public AuthenticateResponse Authenticate(string username, string password)
{
string response = GetResponse(GetUrl(username, password).ToString());
return ParseResponse(response);
}
[TestMethod()]
[ExpectedException(typeof(XmlException))]
public void Authenticate_BadXml_ReturnException()
{
MockRepository mockRepository = new MockRepository();
SSO sso = mockRepository.Stub<SSO>();
sso.Stub(t => t.GetResponse("")).Return("<test>d");
AuthenticateResponse response = sso.Authenticate("test", "test");
}
Your repository is still in "record" mode. You're mixing record/replay semantics (the "old" way of doing things) with the newer AAA (arrange/act/assert) style.
Instead of creating your own repository, simply use:
var sso = MockRepository.GeneateStub<SSO>();
Everything should work fine now.
Your last line is calling the Authenticate method on your stub object, you haven't set up a return or value or exception to throw when calling it, so Rhino Mocks doesn't know what the stub should do and it causes an error. You probably don't want to call a method on your stub - that seems kind of pointless to me, is there another object (that you're actually testing in this test) that you should be calling a method on?
Is that your whole test? If so, your test makes no sense. The only object in your test is the one you're stubbing--where is the subject of the test?
If you're trying to test the SSO class, you absolutely never want to mock/stub it. If SSO has one or more dependencies, use the mocking framework to set up canned interactions between those dependencies and your SUT. That is the exact purpose of a mocking framework.