Mock service without interfaces using rhino mocks - c#

Background
My application is consuming a WCF service via proxyies. I have to unit test my implementation, that it consume the service and processing are done correctly.
Method to be Tested
public class MyClass
{
private ManagerServiceClientImpl myclient;
public void MethodToBeTested();
{
var result = GetServiceData();
if(result!=null)
//some processing
}
}
private MyObject GetServiceData()
{
myclient = ServiceLocator.Current.GetInstance<ManagerServiceClientImpl>();
if(myclient.ConnectToService() && myclient.MyServiceClient.IsConnected)
return myclient.GetData();
else
return null;
}
This is provided by external source, so I have no right to modify it
public class ManagerServiceClientImpl
{
public ServiceClient MyServiceClient { get; private set; }
public bool ConnectToService()
}
How would I mock the ManagerServiceClientImpl it doesn't have interface or methods are not marked as virtual
What i tried so far.
[TestMethod]
public void IsServiceConnected_GetData()
{
//Arrange
ManagerServiceClientImpl clientImpl =
MockRepository.GenerateMock<ManagerServiceClientImpl>();
ServiceLocator.Expect(x => x.GetInstance<ManagerServiceClientImpl>())
.Return(clientImpl);
var testData= new MyObject
{
ID = "Test1",
Name ="test",
}
//Act
_myClass.MethodToBeTested();
//Assert
stubService.AssertWasCalled(h => h.SaveAllChanges());
}
Note: Using Rhino.Mocks. Its my first time using Rhino mocks

As Amittai Shapira mentioned you can mock it without an interface by using unit testing frameworks that support it, i'm using Typemock Isolator and i created an example test for your code:
I've created an instance of MyClass and used a feature of Typemock to mock Non-Public methods to change the return value for GetServiceData
[TestMethod]
public void TestMethod1()
{
var testData = new MyObject
{
ID = "Test1",
Name = "test",
};
var realObj = new MyClass();
Isolate.NonPublic.WhenCalled(realObj, "GetServiceData").WillReturn(testData);
Isolate.NonPublic.WhenCalled(realObj, "SaveAllChanges").CallOriginal();
realObj.MethodToBeTested();
Isolate.Verify.NonPublic.WasCalled(realObj, "SaveAllChanges");
}

In order to use RhinoMocks (or Moq, or any other "constrained" mocking framework), the type you are mocking must support inheritance on the members you want to mock. This means it must either be an interface, or the members must be virtual/abstract. Without that, these frameworks cannot do what they need to do to generate a proxy middle-man at runtime. For more details, see my blog post on how .NET mocking frameworks work under the hood: https://www.wrightfully.com/how-net-mocking-frameworks-work
What you could do is create methods in your own class that wrap the other service such that you could mock your methods and have them return whatever you need, completely bypassing the service.

Related

Autofac mock - How do I setup/fake data from specific methods in dependencies?

I'm new to both unit tests, Autofac and mocks so likely, this is relatively easy, but I'm having a hard time figure it out.
I have this class SystemUnderTest with one dependency, and two methods GetValueOne and GetValueTwo.
public class SystemUnderTest : ISystemUnderTest
{
private readonly IDependency _dependency;
public SystemUnderTest(IDependency dependency)
{
_dependency = dependency;
}
public string GetValueOne()
{
return _dependency.GetValueOne();
}
public string GetValueTwo()
{
return _dependency.GetValueTwo();
}
}
public interface ISystemUnderTest
{
string GetValueOne();
string GetValueTwo();
}
These methods gets data from the dependency.
public class Dependency : IDependency
{
public string GetValueOne()
{
return "get-value-one";
}
public string GetValueTwo()
{
return "get-value-two";
}
}
public interface IDependency
{
string GetValueOne();
string GetValueTwo();
}
I'm trying to fake the data from one of the methods (the "GetValueTwo") so its returning "expected value" instead of "get-value-two" which is what the dependency normally returns.
[Fact]
public async Task Test_SystemUnderTest()
{
using (var mock = AutoMock.GetLoose())
{
// Setup
mock.Mock<IDependency>().Setup(x => x.GetValueTwo()).Returns("expected value");
// Configure
mock.Provide<IDependency, Dependency>();
// Arrange - configure the mock
var sut = mock.Create<SystemUnderTest>();
// Act
var actual_GetValueOne = sut.GetValueOne();
var actual_GetValueTwo = sut.GetValueTwo();
// Assert - assert on the mock
Assert.Equal("get-value-one", actual_GetValueOne);
Assert.Equal("expected value", actual_GetValueTwo);
}
}
The first part in my test, the Setup piece, does not seem to have any effect, and its probably because I'm doing some basic stuff wrong.
Anyone with insights on how to save my day?
The members of Dependency implementation would need to have virtual members for them to be able to be overridden when doing a partial mocked.
public class Dependency : IDependency {
public virtual string GetValueOne() {
return "get-value-one";
}
public virtual string GetValueTwo() {
return "get-value-two";
}
}
Then similar to what was suggested in another answer you would instead mock the implementation, making sure to enable it to call base members and only setup the members you need to override.
public void Test_SystemUnderTest() {
using (var mock = AutoMock.GetLoose()) {
// Setup
var dependency = mock.Mock<Dependency>();
dependency.CallBase = true;
dependency.Setup(x => x.GetValueTwo()).Returns("expected value");
// Configure
mock.Provide<IDependency>(dependency.Object);
// Arrange - configure the mock
var sut = mock.Create<SystemUnderTest>();
// Act
var actual_GetValueOne = sut.GetValueOne();
var actual_GetValueTwo = sut.GetValueTwo();
// Assert - assert on the mock
Assert.AreEqual("get-value-one", actual_GetValueOne);
Assert.AreEqual("expected value", actual_GetValueTwo);
}
}
The above passes when exercised provided that the members of the implementation that need to be mocked can be overridden (ie virtual).
Not an expert in writing unit tests, but I'm pretty sure that by using Provide with two type arguments, you overwrite the Setup part you did previously. By my understanding, the Provide method should be used to provide your own mock implementation of target interface, so using both Provide with two type arguments and Setup for the same dependency doesn't make sense.
So you can either modify the Dependency implementation's GetValueTwo to return "expected value" and use the rest of your code unmodified, or you can supply the mocked instance to the Provide method with one type argument, with both of the methods previously setup, like this:
[Fact]
public async Task Test_SystemUnderTest()
{
using (var mock = AutoMock.GetLoose())
{
var mockedDependency = mock.Mock<IDependency>();
// Setup
mockedDependency.Setup(x => x.GetValueOne()).Returns("get-value-one");
mockedDependency.Setup(x => x.GetValueTwo()).Returns("expected value");
// The following line is not even necessary
mock.Provide<IDependency>(mockedDependency.Object);
// Arrange - configure the mock
var sut = mock.Create<SystemUnderTest>();
// Act
var actual_GetValueOne = sut.GetValueOne();
var actual_GetValueTwo = sut.GetValueTwo();
// Assert - assert on the mock
Assert.Equal("get-value-one", actual_GetValueOne);
Assert.Equal("expected value", actual_GetValueTwo);
}
}

Unti Test: Mock a method result

public void Pay()
{
// some insert db code
// ...
// Call Bank api
BankApi api = new BankApi();
int result = api.pay();
if(result == 1)
{
//...
}
else
{
//...
}
}
I dont want to call api in unit test. How to mock the pay method without modify inner code (such as the line new BankApi() code)?
Its possible to mock your BankApi class without changing any of your legacy code, you just need a unit testing framework that allows you to mock concrete classes.
for example a test for your method with Typemock :
[TestMethod]
public void ExampleTest()
{
//fakes the next BankApi instace
var handler = Isolate.Fake.NextInstance<BankApi>();
//change the pay method behavior
Isolate.WhenCalled(() => handler.pay()).WillReturn(1);
new ClassUnderTest().Pay();
}
First, as stated, you should create an Interface.
public interface IBankApi
{
int pay();
}
Then, what you can do is mock this interface like this (I'm using Moq "Mock you" here, you will need to add the NuGet package "Moq" as reference to your application, and you could use other mocking libraries of course)
apiMock = new Mock<IBankApi>();
just after that you will tell what this call should return (that would be actual mocking)
apiMock.Setup(x => x.pay()).Returns(1); //
Then, this api "pseudo object", can be used by using apiMock.Object
Now , this information I just gave you doesn't directly solve your problem.
As stated in the comments, you need a better uncoupling of your code.
You need, for example, some kind of "dependency injection" to allow for such a uncoupling.
Here is a simple example of how it can be done :
public class ClassThatUsesYourBankApi
{
private readonly IBankApi _api;
// the constructor will be given a reference to the interface
public ClassThatUsesYourBankApi (IBankApi api)
{
// here you could check for null parameter and throw exception as needed
this._api = api;
}
// this method can now be tested with the mock interface
public void MethodThatUseTheApi()
{
int result = this._api.pay();
if (result == 1)
{
// some things that happens
}
else
{
// some other thing
}
}
}
How to unit test that method :
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Moq;
[TestClass]
public class TestMyMethod
{
[TestMethod]
public void MyMethod_WithBankApiReturns1_ShouldHaveThingsThatHappens()
{
// Arrange
var apiMock = new Mock<IBankApi>();
apiMock.Setup(api => api.pay())
.Returns(1);
var myObject = new ClassThatUsesYourBankApi(apiMock.Object);
// Act
int result = myObject.MethodThatUseTheApi();
// Assert
// Here you test that the things that should have happened when the api returns 1 actually have happened.
}
}
The key thing to understand here, is that you must not instantiate the api you need to mock in the method you want to test
In other words, "uncoupling" your method with your api is done by programming to an interface, and code such as you don't have
var api = new BankApi()
directly in the method you want to unit test.
I showed a way to do that, and there are other.

Mocking a ViewModel for unit testing with Moq?

New to unit testing. I have a WPF client app hooked into a WCF service via basicHttpbinding. Everything works great. I'm using simple constructor Dependency Injection in my viewModel, passing in an IServiceChannel which I then call me service methods on e.g:
IMyserviceChannel = MyService;
public MyViewModel(IMyServiceChannel myService)
{
this.MyService = myService;
}
Private void GetPerson()
{
var selectedPerson = MyService.GetSelectedPerson();
}
I have then added an MS Test project in the client app and I'm trying to use Moq to mock my service:
[TestMethod]
public void GetArticleBody_Test_Valid()
{
// Create channel mock
Mock<IIsesServiceChannel> channelMock = new Mock<IIsesServiceChannel>(MockBehavior.Strict);
// setup the mock to expect the Reverse method to be called
channelMock.Setup(c => c.GetArticleBody(1010000008)).Returns("110,956 bo/d, 1.42 Bcfg/d and 4,900 bc/d. ");
// create string helper and invoke the Reverse method
ArticleDataGridViewModel articleDataGridViewModel = new ArticleDataGridViewModel(channelMock.Object);
string result = channelMock.GetArticleBody(1010000008);
//Assert.AreEqual("cba", result);
//verify that the method was called on the mock
channelMock.Verify(c => c.GetArticleBody(1010000008), Times.Once());
}
The test is failing with a System.NullReferenceException. Object reference not set to an instance of an object. at the method invocation here:
string result = articleDataGridViewModel.IsesService.GetArticleBody(1010000008);
so I'm wandering whether this is the best way to approach or am I better somehow mocking an isolated part of the viewModel which is applicable to the test?
The NullReferenceException is mybe thrown because you use MockBehavior.Strict. The documentation says:
Causes this mock to always throw an exception for invocations that don't have a corresponding setup.
Maybe the constructor of ArticleDataGridViewModel calls other methods of the service which you haven't set up.
Another issue is, that you are calling the mocked method directly. Instead you should call a method of your view model, which calls this method.
[TestMethod]
public void GetArticleBody_Test_Valid()
{
// Create channel mock
Mock<IIsesServiceChannel> channelMock = new Mock<IIsesServiceChannel>();
// setup the mock to expect the Reverse method to be called
channelMock.Setup(c => c.GetArticleBody(1010000008)).Returns("110,956 bo/d, 1.42 Bcfg/d and 4,900 bc/d. ");
// create string helper and invoke the Reverse method
ArticleDataGridViewModel articleDataGridViewModel = new ArticleDataGridViewModel(channelMock.Object);
string result = articleDataGridViewModel.MethodThatCallsService();
//Assert.AreEqual("cba", result);
//verify that the method was called on the mock
channelMock.Verify(c => c.GetArticleBody(1010000008), Times.Once());
}
Besides that I think there is no problem with your approach. Maybe the view model violates the single responsibility principle and does more than it should, but that's hard to tell on the basis of your code example.
EDIT: Here's a full example of how you could test something like this:
public interface IMyService
{
int GetData();
}
public class MyViewModel
{
private readonly IMyService myService;
public MyViewModel(IMyService myService)
{
if (myService == null)
{
throw new ArgumentNullException("myService");
}
this.myService = myService;
}
public string ShowSomething()
{
return "Just a test " + this.myService.GetData();
}
}
class TestClass
{
[TestMethod]
public void TestMethod()
{
var serviceMock = new Mock<IMyService>();
var objectUnderTest = new MyViewModel(serviceMock.Object);
serviceMock.Setup(x => x.GetData()).Returns(42);
var result = objectUnderTest.ShowSomething();
Assert.AreEqual("Just a test 42", result);
serviceMock.Verify(c => c.GetData(), Times.Once());
}
}
Without access to your viewmodel, there's only so much help that we can provide you.
However, this code:
Mock<IIsesServiceChannel> channelMock = new Mock<IIsesServiceChannel>(MockBehavior.Strict);
...
ArticleDataGridViewModel articleDataGridViewModel = new ArticleDataGridViewModel(channelMock.Object);
...
string result = articleDataGridViewModel.IsesService.GetArticleBody(1010000008);
Does not set up your IsesService. If it is not set up in your constructor, that means the IsesService is a null reference. You can't call a method on a null object.
Consider mocking out at a higher level of abstraction then the tight coupling you have with the tool your using.
Perhaps your view-model should rely on services and not a detail of the tool that your using (i.e. IIsesServiceChannel).
Here's an example:
Construct testable business layer logic

Mocking HttpContext.server.MapPath in ASP.NET unit testing

I have working in unit testing in ASP.Net web application, now I have accessing my constructor in the model file to test which has Server.MapPath code for uploading my XMLfile, when try to testing this i get error, because the HttpContext is null so i have to mocking Server.MapPath.
I have searched lot but every samples given only for Asp.NET MVC but I have working in ASP.NET. so please help in ASP.NET to solve this issue.
My code is given below.
public class NugetPlatformModel
{
public bool IsHavingLicense { get; set; }
public List<PlatformProducts> PlatformProduct = new List<PlatformProducts>();
public NugetPlatformModel()
{
var xmldoc = new XmlDocument();
mldoc.Load(HttpContext.Current.Server.MapPath(#"~\Content\PlatformProducts.xml"));
}
}
And my unit testing code
[Test]
public void Account_UnlicensedCustomerIdentity_IsStudioLicenseAndIshavinglicenseFalse()
{
//Act
NugetPlatformModel nugetPlatformModel = new NugetPlatformModel();
//Assert
AssertEquals(false, nugetPlatformModel.IsHavingLicense);
}
This is typical with code that calls static methods, it's very difficult to test while preserving separation of concern and avoiding tight coupling. Here is a generic approach to test and mock "untestable code": write a "facade wrapper" to it.
Create a wrapper for these methods. A simple class that contains methods named sensibly, and only delegates to the untestable calls (typically static calls)
Create an interface to that wrapper class
Instead of directly calling the untestable methods in your client code, use the wrapper (dependency-injected using the interface provided in step 2) and call normal methods on it.
In your unit-test, mock the wrapper with the behaviour you want.
This approach effectively reduces the coupling and separates the concerns that need to be separated. Of course, you still can't test the behaviour of the wrapper itself, but if it's simple enough (only delegating to the original calls) then it's not as big a problem.
Update:
Using shims to isolate your application from other assemblies for unit testing
Shim types are one of two technologies that the Microsoft Fakes Framework uses to let you easily isolate components under test from the environment. Shims divert calls to specific methods to code that you write as part of your test. Many methods return different results dependent on external conditions, but a shim is under the control of your test and can return consistent results at every call. This makes your tests much easier to write.
Use shims to isolate your code from assemblies that are not part of your solution. To isolate components of your solution from each other, we recommend that you use stubs.
How already answered, you should decouple your system
public class NugetPlatformModel
{
public bool IsHavingLicense { get; set; }
public List<PlatformProducts> PlatformProduct = new List<PlatformProducts>();
public NugetPlatformModel(IPlatformProductProvider provider)
{
var xmldoc = new XmlDocument();
//System.Web.HttpContext.Current.Server.MapPath(#"~\Content\PlatformProducts.xml")
xmldoc.Load(provider.Filepath);
}
public interface IPlatformProductProvider
{
string Filepath { get; }
}
public class PlatformProductProvider: IPlatformProductProvider
{
string _filepath;
public string Filepath
{
get { return _filepath; }
set { _filepath = value;}
}
public PlatformProductProvider(string path)
{
_filepath = path;
}
}
}
And your test could be:
[Test]
public void Account_UnlicensedCustomerIdentity_IsStudioLicenseAndIshavinglicenseFalse()
{
//Arrange
// using Moq
//var mock = new Mock<IPlatformProductProvider>();
//IPlatformProductProvider provider = mock.Object;
//provider.Filepath = "pippo.xml";
// otherwise
var provider = new PlatformProductProvider("pippo.xml");
//Act
NugetPlatformModel nugetPlatformModel = new NugetPlatformModel(provider);
//Assert
AssertEquals(false, nugetPlatformModel.IsHavingLicense);
}
If you can't modify the source code, try using shims (https://msdn.microsoft.com/en-us/library/hh549176.aspx).

Mocked Object Still Making Calls to Service

So I'm writing tests for our MVC4 application and I'm testing Controller actions specifically. As I mention in the title, the test still hits the service (WCF) instead of returning test data. I have this controller:
public class FormController : Controller
{
public SurveyServiceClient Service { get; set; }
public SurveyDao Dao { get; set; }
public FormController(SurveyServiceClient service = null, SurveyDao dao = null)
{
this.Service = service ?? new SurveyServiceClient();
this.Dao = dao ?? new SurveyDao(Service);
}
//
// GET: /Form/
public ActionResult Index()
{
var formsList = new List<FormDataTransformContainer>();
Dao.GetForms().ForEach(form => formsList.Add(form.ToContainer()));
var model = new IndexViewModel(){forms = formsList};
return View("Index", model);
}
And it uses this DAO object:
public class SurveyDao
{
private readonly SurveyServiceClient _service;
private readonly string _authKey;
public SurveyDao(SurveyServiceClient serviceClient)
{
_service = serviceClient;
}
....
public FormContract[] GetForms()
{
var forms = _service.RetrieveAllForms();
return forms;
}
And this is my test using JustMock, the mock on GetForms() returns some test data in a helper class:
[TestClass]
public class FormControllerTest
{
private SurveyDao mockDao;
private SurveyServiceClient mockClient;
public FormControllerTest()
{
mockClient = Mock.Create<SurveyServiceClient>();
mockDao = Mock.Create<SurveyDao>(mockClient);
}
[TestMethod]
public void TestIndexAction()
{
//Arrange
var controller = new FormController(mockClient, mockDao);
Mock.Arrange(() => mockDao.GetForms()).Returns(TestHelpers.FormContractArrayHelper);
//Act
var result = controller.Index() as ViewResult;
//Assert
Assert.IsInstanceOfType(result.Model, typeof(IndexViewModel));
}
}
My problem is that when I run the test, the Service is still being called. I've verified this using Fiddler as well as debugging the test and inspecting the value of "result" which is populated with our service's test data.
EDIT:
I've changed the test constructor to be a [TestInitialize] function, so the Test now looks like this:
[TestClass]
public class FormControllerTest
{
private SurveyDao mockDao;
private SurveyServiceClient mockClient;
[TestInitialize]
public void Initialize()
{
mockClient = Mock.Create<SurveyServiceClient>();
mockDao = Mock.Create<SurveyDao>(Behavior.Strict);
}
[TestMethod]
public void TestIndexAction()
{
//Arrange
var controller = new FormController(mockClient, mockDao);
Mock.Arrange(() => mockDao.GetForms()).Returns(TestHelpers.FormContractArrayHelper);
//Act
var result = controller.Index() as ViewResult;
//Assert
Assert.IsInstanceOfType(result.Model, typeof(IndexViewModel));
}
}
Please verify that you are using the correct assembly for JustMock. There are a few different ones (VisualBasic, Silverlight, JustMock). The JustMock one is the one you should be including in your project.
Failure to include the correct one will cause the behavior that you are describing (method not being properly stubbed).
The JustMock manual explains (highlights by me):
By default Telerik JustMock uses loose mocks and allows you to call
any method on a given type. No matter whether the method call is
arranged or not you are able to call it.
You can control this behavior when calling the Create() method of you Mock:
var foo = Mock.Create<IFoo>(Behavior.Strict);
There you can specify what the mock object should do if you have not explicitly implemented a certain method. In your case (I think it is the default behavior) the mock indeed calls the original method on the object that you want to mock.
You have the following choices in the Behavior Enumeration enumeration:
Loose: Specifies that by default mock calls will behave like a stub, unless explicitly setup.
RecursiveLoose: Specifies that by default mock calls will return mock objects, unless explicitly setup.
Strict: Specifies that any calls made on the mock will throw an exception if not explictly set.
CallOriginal: Specifies that by default all calls made on mock will invoke its corresponding original member unless some expecations are set.

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