[TestMethod()]
public void ShowSetup_SendsMessage_WhenShowSetupCommandCalled()
{
//Arrange
Messenger.Reset();
MainViewModel target = new MainViewModel();
bool wasCalled = false;
Messenger.Default.Register<NotificationMessage>(this,"Settings",(msg) => wasCalled = true);
//Act
target.ShowSetupCommand.Execute(null);
//Assert
Assert.IsTrue(wasCalled);
}
I see there is an IMessenger interface and I tried to mock it and set Messenger.OverrideDefault to the mock like this:
var mock = new Mock<IMessenger>();
Messenger.OverrideDefault((Messenger)mock.Object);
But I got an invalid cast error. Is the OverrideDefault method not for that purpose or more likely I'm using it incorrectly.
Or would I have an interface for the classes that are receiving the messages and mock those? All I really want to test is that a RelayCommand sends a message when it is called.
I just started to look at this myself. I'm a little surprised that Messenger.OverrideDefault doesn't take an IMessenger as a parameter. You have to inherit Messenger.
I suppose you could create a class that internally uses your mock object and then do a Verify.
[Test]
public void ShowSetup_SendsMessage_WhenShowSetupCommandCalled() {
Messenger.Reset();
MaintenanceViewModel target = new MainViewModel();
IMessenger mockMessenger = MockRepository.GenerateMock<IMessenger>();
mockMessenger.Expect(m => m.Send("Settings"));
TestMessenger testMessenger = new TestMessenger(mockMessenger);
Messenger.OverrideDefault(testMessenger);
bool wasCalled = false;
Messenger.Default.Register<NotificationMessage>(this, "Settings", (msg) => wasCalled = true);
target.ShowSetupCommand.Execute(null);
mockMessenger.VerifyAllExpectations();
}
You may or may not need a stub on the Register method.
The TestMessenger class:
public class TestMessenger : Messenger {
private IMessenger _mockMessenger;
public TestMessenger(IMessenger mock) {
_mockMessenger = mock;
}
public override void Register<TMessage>(object recipient, bool receiveDerivedMessagesToo, Action<TMessage> action) {
_mockMessenger.Register<TMessage>(recipient, receiveDerivedMessagesToo, action);
}
public override void Register<TMessage>(object recipient, Action<TMessage> action) {
_mockMessenger.Register<TMessage>(recipient, action);
}
public override void Send<TMessage, TTarget>(TMessage message) {
_mockMessenger.Send<TMessage, TTarget>(message);
}
public override void Send<TMessage>(TMessage message) {
_mockMessenger.Send<TMessage>(message);
}
public override void Unregister<TMessage>(object recipient, Action<TMessage> action) {
_mockMessenger.Unregister<TMessage>(recipient, action);
}
public override void Unregister<TMessage>(object recipient) {
_mockMessenger.Unregister<TMessage>(recipient);
}
public override void Unregister(object recipient) {
_mockMessenger.Unregister(recipient);
}
}
Another approach that using constructor injection you can see in this answer. I think it's better to use constructor injection instead of using static Messenger.Default. It's more robust approach cause dependency injection providing natural seam with which you can easily substitute dependencies in unit tests. If you try to substitute static member call, then you rely on internal implementation that obviously can change.
Related
I have a simple Http module:
public class CustomLoggingModule : IHttpModule
{
public void Init(HttpApplication context)
{
context.BeginRequest += BeginRequest;
context.EndRequest += EndRequest;
}
public void BeginRequest(object sender, EventArgs eventArgs)
{
//some code
}
public void EndRequest(object sender, EventArgs eventArgs)
{
//some
}
public void Dispose()
{
}
}
How can I unit test this? Especially how is it possible to mock events? Can anyone give some simple example?
Not sure why you have decided to hardwire the dependencies as new LogService() and new HttpContextWrapper(HttpContext.Current) within the CustomLoggingModule. If want to test whether LogInfo() method is called or not, it becomes lot easier if you can externalize these dependencies so you can inject stubbed/mocked version etc.
Also your question does not state that you are using an IOC container. You can register the HttpModule with the container and provide external dependencies at runtime. Your question also does not state that using an isoloation/mock object framework.
Therefore I will provide you with a solution that you can verify whether LogInfo method is called, using hand written stubs and mocks.
To achieve this, we need to refactor CustomLoggingModule a bit, so it becomes more testable.
System Under Test (SUT)
public class CustomLoggingModule : IHttpModule
{
public ILogService LogService { get; set; }
public Func<ILoggingHttpContextWrapper> LogginHttpContextWrapperDelegate { get; set; }
public void Init(HttpApplication context) {
context.BeginRequest += BeginRequest;
context.EndRequest += EndRequest;
}
public CustomLoggingModule() {
LogginHttpContextWrapperDelegate = () => new LoggingHttpContextWrapper();
}
public void BeginRequest(object sender, EventArgs eventArgs) {
LogService.LogInfo(LogginHttpContextWrapperDelegate().HttpContextWrapper);
}
public void EndRequest(object sender, EventArgs eventArgs) {
//some
}
public void Dispose(){ }
}
As you see above, I have introduced 2 additional properties - ILogService so I can provide a Mocked verion and a delegate Func which allows me to stub the
new HttpContextWrapper(HttpContext.Current);
public interface ILoggingHttpContextWrapper {
HttpContextWrapper HttpContextWrapper { get; }
}
public class LoggingHttpContextWrapper : ILoggingHttpContextWrapper
{
public LoggingHttpContextWrapper() {
HttpContextWrapper = new HttpContextWrapper(HttpContext.Current);
}
public HttpContextWrapper HttpContextWrapper { get; private set; }
}
And then your real ILogService
public interface ILogService {
void LogInfo(HttpContextWrapper httpContextWrapper);
}
public class LogService : ILogService {
public void LogInfo(HttpContextWrapper httpContextWrapper)
{
//real logger implementation
}
}
Unit Test :
You would create a MockLoggerService, so you can verify the interaction i,e whether the LogInfo() method was called, etc. You also need a stubbed LoggingHttpContextWrapper to provide the fake HttpContextWrapper to the SUT (System Under Test)/ CustomLoggingModule.
public class StubLoggingHttpContextWrapper : ILoggingHttpContextWrapper
{
public StubLoggingHttpContextWrapper(){}
public HttpContextWrapper HttpContextWrapper { get; private set; }
}
public class MockLoggerService : ILogService
{
public bool LogInfoMethodIsCalled = false;
public void LogInfo(HttpContextWrapper httpContextWrapper) {
LogInfoMethodIsCalled = true;
}
}
MockLoggerService is very important. It is not the real logger service, but it is the mocked version. When we do public class MockLoggerService : ILogService this means that we are providing another layer of indirection to the logger service so we can verify the interaction of the behaviour.
You also notice that I have provided a boolean variable to verify whether the LogInfo method is called or not. This allows me to call this method from the SUT, and verify whether the method being called or not.
Now Your Unit Test can be implemented as below.
[TestMethod]
public void CustomLoggingModule_BeginRequest_VerifyLogInfoMethodIsCalled()
{
var sut = new CustomLoggingModule();
var loggerServiceMock = new MockLoggerService();
var loggingHttpContextWrapperStub = new StubLoggingHttpContextWrapper();
sut.LogService = loggerServiceMock;
sut.LogginHttpContextWrapperDelegate = () => loggingHttpContextWrapperStub;
sut.BeginRequest(new object(), new EventArgs());
Assert.IsTrue(loggerServiceMock.LogInfoMethodIsCalled);
}
I had the same issue with my custom http module and decided I won't give up that easily and will do all I can to trigger the BeginRequest event in unit test. I had to actually read through the source code of HttpApplication class and use reflection to invoke the method.
[TestMethod]
public void EventTriggered_DoesNotError()
{
using (var application = new HttpApplication())
{
var module = new CustomLoggingModule();
module.Init(application);
FireHttpApplicationEvent(application, "EventBeginRequest", this, EventArgs.Empty);
}
}
private static void FireHttpApplicationEvent(object onMe, string invokeMe, params object[] args)
{
var objectType = onMe.GetType();
object eventIndex = (object)objectType.GetField(invokeMe, System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic).GetValue(onMe);
EventHandlerList events = (EventHandlerList)objectType.GetField("_events", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic).GetValue(onMe);
EventHandler handler = (EventHandler)events[eventIndex];
Delegate[] delegates = handler.GetInvocationList();
foreach (Delegate dlg in delegates)
{
dlg.Method.Invoke(dlg.Target, args);
}
}
I'm trying to test the function GetcallEntityBycallEntity (Guid callId) with Mock library.
this function calls another class that does not implement any interface.
protected virtual CallFacade CallFacade()
{
return new CallFacade();
}
public Note GetCallEntityByCallEntity(Guid CallEntity)
{
myCall= null;
**CallFacade** callFacade = Get CallFacade();
if (CallEntity!= Guid.Empty)
{
myCall = callFacade.GetCallByEntityId(CallEntity);
}
return myCall;
}
CallFacade Not is an Interface
in my test:
[TestInitialize]
public void TestInitialization()
{
IoCMocks.Initialize();
CommonCallFacadeMock = new CommonCallFacadeMock();
}
public void GetCallEntityByNoteEntity_GetCall_ReturnValidCall()
{
//Arrange
CallmyNote = GetmyCall(); //private method. == Call.CreateCall();
//Stubs
CommonCallFacadeMock.MockCallFacade.Setup(x => x.GetCallByEntityId(ExistingCallEntity)).Returns(myCall);
//Action
var obtained = CommonCallFacadeMock.GetCallEntityByCallEntity(ExistingCallEntity);
CommonCallFacadeMock.MockCallFacade.Verify(x => x.GetCallByEntityId(It.IsAny<Guid>()), Times.Once());
}
You get this error message because MOQ can mock only interfaces, abstract methods or properties on abstract classes, virtual methods or properties on concrete classes.
You have to mark method GetCallByEntityId as virtual.
There is an old discussion in "Moq Discussions" google group about virtual methods.
I have been given the task to evaluate codeFirst and possible to use for all our future projects.
The evaluation is based on using codeFirst with an existing database.
Wondering if it's possible to mock the repository using codeFirst 4.1.(no fakes)
The idea is to inject a repository into a service and moq the repository.
I have been looking on the net but I have only found an example using fakes.I dont want to use fakes I want to use moq.
I think my problem is in the architecture of the DAL.(I would like to use unitOfWork etc.. by I need to show a working moq example)
Below is my attempt(Failed miserably) due to lack of knowledge on Code first 4.1.
I have also uploaded a solution just in case somebody is in good mood and would like to change it.
http://cid-9db5ae91a2948485.office.live.com/browse.aspx/Public%20Folder?uc=1
I am open to suggestions and total modification to my Dal.Ideally using Unity etc.. but I will worry about later.
Most importantly I need to be able to mock it. Without ability to use MOQ we will bin the project using EF 4.1
Failed attempt
//CodeFirst.Tests Project
[TestClass]
public class StudentTests
{
[TestMethod]
public void Should_be_able_to_verify_that_get_all_has_been_called()
{
//todo redo test once i can make a simple one work
//Arrange
var repository = new Mock<IStudentRepository>();
var expectedStudents = new List<Student>();
repository.Setup(x => x.GetAll()).Returns(expectedStudents);
//act
var studentService = new StudentService(repository.Object);
studentService.GetAll();
//assert
repository.Verify(x => x.GetAll(), Times.AtLeastOnce());
}
}
//CodeFirst.Common Project
public class Student
{
public int StudentId { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
}
public interface IStudentService
{
IEnumerable<Student> GetAll();
}
//CodeFirst.Service Project
public class StudentService:IStudentService
{
private IStudentRepository _studentRepository;
public StudentService()
{
}
public StudentService(IStudentRepository studentRepository)
{
_studentRepository = studentRepository;
}
public IEnumerable<Student> GetAll()
{
//TODO when mocking using moq this will actually call the db as we need a separate class.
using (var ctx = new SchoolContext("SchoolDB"))
{
_studentRepository = new StudentRepository(ctx);
var students = _studentRepository.GetAll().ToList();
return students;
}
}
}
//CodeFirst.Dal Project
public interface IRepository<T> where T : class
{
T GetOne(Expression<Func<T, bool>> predicate);
IEnumerable<T> GetAll();
IEnumerable<T> Find(Expression<Func<T, bool>> predicate);
void Add(T entity);
void Delete(T entity);
T Single(Func<T, bool> predicate);
T First(Func<T, bool> predicate);
}
public class RepositoryBase<T> : IRepository<T> where T : class
{
private readonly IDbSet<T> _dbSet;
public RepositoryBase(DbContext dbContext)
{
_dbSet = dbContext.Set<T>();
if (_dbSet == null) throw new InvalidOperationException("Cannot create dbSet ");
}
protected virtual IDbSet<T> Query
{
get { return _dbSet; }
}
public T GetOne(Expression<Func<T, bool>> predicate)
{
return Query.Where(predicate).FirstOrDefault();
}
public IEnumerable<T> GetAll()
{
return Query.ToArray();
}
public IEnumerable<T> Find(Expression<Func<T, bool>> predicate)
{
return Query.Where(predicate).ToArray();
}
public void Add(T entity)
{
_dbSet.Add(entity);
}
public void Delete(T entity)
{
_dbSet.Remove(entity);
}
public T Single(Func<T, bool> predicate)
{
return Query.Where(predicate).SingleOrDefault();
}
public T First(Func<T, bool> predicate)
{
return Query.Where(predicate).FirstOrDefault();
}
}
public class SchoolContext:DbContext
{
public SchoolContext(string connectionString):base(connectionString)
{
Database.SetInitializer<SchoolContext>(null);
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//Not sure why I have to do this.Without this when using integration testing
//as opposed to UnitTests it does not work.
modelBuilder.Entity<Student>().ToTable("Student"); }
public DbSet<Student> Students { get; set; }
}
public interface IStudentRepository:IRepository<Student>
{
}
public class StudentRepository : RepositoryBase<Student>, IStudentRepository
{
public StudentRepository(DbContext dbContext)
: base(dbContext)
{
}
public IEnumerable<Student> GetStudents()
{
return GetAll();
}
}
Again feel free to modify or whatever is needed to help me to get something together.
Thanks a lot for your help
When I started with repository and unit of work patterns I used the implementation similar to this (it is for ObjectContext API but converting it to DbContext API is simple). We used that implementation with MOQ and Unity without any problems. By the time implementations of repository and unit of work have evolve as well as the approach of injecting. Later on we found that whole this approach has serious pitfalls but that was alredy discussed in other questions I referenced here (I highly recommend you to go through these links).
It is very surprising that you are evaluating the EFv4.1 with high emphasis on mocking and unit testing and in the same time you defined service method which is not unit-testable (with mocking) at all. The main problem of you service method is that you are not passing repository/context as dependency and because of that you can't mock it. The only way to test your service and don't use the real repository is using some very advanced approach = replacing mocking and MOQ with detouring (for example Moles framework).
First what you must do is replacing your service code with:
public class StudentService : IStudentService
{
private readonly IStudentRepository _studentRepository;
public StudentService(IStudentRepository studentRepository)
{
_studentRepository = studentRepository;
}
public IEnumerable<Student> GetAll()
{
return _studentRepository.GetAll().ToList();
}
}
Btw. this is absolutely useless code and example of silly layering which doesn't offer any useful functionality. Just wrapping the call to repository only shows that service is not needed at all as well as unit testing this method is not needed. The main point here is integration test for GetAll method.
Anyway if you want to unit thest such method with MOQ you will do:
[TestClass]
public class StudentsServiveTest
{
private Mock<IRespository<Student>> _repo;
[TestInitialize]
public void Init()
{
_repo = new Mock<IRepository<Student>>();
_repo.Setup(r => r.GetAll()).Returns(() => new Student[]
{
new Student { StudentId = 1, Name = "A", Surname = "B" },
new Student { StudentId = 2, Name = "B", Surname = "C" }
});
}
[TestMethod]
public void ShouldReturnAllStudents()
{
var service = new StudentsService(_repo.Object);
var data = service.GetAll();
_repo.Verify(r => r.GetAll(), Times.Once());
Assert.IsNotNull(data);
Assert.AreEqual(2, data.Count);
}
}
The issue from what I can see is that you are throwing away the mock object and newing up a new instance
_studentRepository = new StudentRepository(ctx);
Perhaps add a method on the interface to add the context object and reuse the same instance that was injected in the constructor.
using (var ctx = new SchoolContext("SchoolDB"))
{
_studentRepository.Context = ctx;
var students = _studentRepository.GetAll().ToList();
return students;
}
}
Consider the following service interfaces:
public interface IServiceA
{
void DoSomething(string s);
void DoSomething(string s, bool b);
}
public interface IServiceB
{
void DoSomething();
}
The implementation of IServiceB depends on IServiceA like this:
public class ServiceB : IServiceB
{
private IServiceA _serviceA;
public ServiceB(IServiceA serviceA)
{
_serviceA = serviceA;
}
public void DoSomething()
{
_serviceA.DoSomething("Hello", true);
}
}
Ie. the dependency is injected in the constructor.
Now consider a unit test for the DoSomething() method. I wish to assert that one of the overloaded DoSomething-methods in IServiceA is called, but following a general principle that unit tests shouldn't know too much about the internal workings of the method being tested, I wish to be agnostic about which of the two overloads is called. Consider the following unit test:
[TestFixture]
public class ServiceBTests
{
[Test]
public void DoSomething_CallsServiceA()
{
var serviceAMock = MockRepository.GenerateMock<IServiceA>();
var service = new ServiceB(serviceAMock);
service.DoSomething();
// Problem: How to check if EITHER:
serviceAMock.AssertWasCalled(s => s.DoSomething(Arg<String>.Is.NotNull, Arg<bool>.Is.Anything));
// OR:
serviceAMock.AssertWasCalled(s => s.DoSomething(Arg<String>.Is.NotNull));
}
}
How can I assert that either one or the other of the two methods was called?
You could manually set a boolean flag like so:
[TestFixture]
public class ServiceBTests
{
[Test]
public void DoSomething_CallsServiceA()
{
var serviceAMock = MockRepository.GenerateMock<IServiceA>();
bool called = false;
serviceAMock.Stub(
x => x.DoSomething(Arg<String>.Is.NotNull, Arg<bool>.Is.Anything))
.WhenCalled(delegate { called = true; });
serviceAMock.Stub(x => x.DoSomething(Arg<String>.Is.NotNull))
.WhenCalled(delegate { called = true; });
var service = new ServiceB(serviceAMock);
service.DoSomething();
Assert.IsTrue(called);
}
}
I don't think this very useful though. Unit tests are concerned with anything that is observable from outside of the component boundaries. Method calls to mocks are part of that. In other words, it is OK if you test for a specific overload being called. After all, there must be a reason why you use that overload and not the other one.
If you really want the unit test to remain ignorant of the implementation, you wouldn't be allowed to assert method calls on mocks at all. That would be a severe restriction on your ability to write tests.
Is there a way to do a conditional TearDown in NUnit?
I have a TestFixture which has a need to run cleanup code for just a few tests, and I don't really want to:
Run the TearDown method on every test
Create a private helper method and call it from the tests requiring cleanup if I can avoid it
There isn't unfortunately.
Can you not do the cleanup in the [TestFixtureTearDown] instead, so once all the tests have finished? I guess that depends on whether the cleanup has to be done before the next test runs.
Alternatively, put those tests that require a cleanup in another class/TextFixture together, away from the other tests. Then you can use a TearDown in there which doesn't need to be conditional.
Edit:
One thing I've just thought of, which could be done to achieve the aim though probably isn't actually worth it for this particular need, is that you can extend NUnit - create your own custom attributes which you could handle however you wanted. This is mentioned here. Like I say, I don't think really you should go down that route for this, but is useful to know none-the-less
You can have the main TearDown in a base class:
[TearDown]
public virtual void TearDown()
{
// Tear down things here
}
and then override it in the class where you have the tests that should not run the tear down code:
[TearDown]
public override void TearDown()
{
// By not calling base.TearDown() here you avoid tearing down
}
Extend all you classes with test from BaseTest
public class BaseTest
{
[SetUp]
public void BeforeTest()
{
GetService<NUnitHooksController>().ExecuteBeforeTestHooks(this);
}
[TearDown]
public void AfterTest()
{
GetService<NUnitHooksController>().ExecuteAfterTestHooks(this);
}
}
Use AfterTest and BeforeTest hooks. Works both with and without category.
public class ExampleTest : BaseTest
{
[Test, Category("asdasd")]
public void Test01()
{
...
}
[AfterTest("asdasd")]
public void ExampleHook()
{
...
}
}
public class NUnitHooksController
{
private readonly ILogger _log;
public NUnitHooksController(ILogger log)
{
_log = log;
}
public void ExecuteBeforeTestHooks(object testClass)
{
ExecuteHooks(testClass, typeof(BeforeTestAttribute));
}
public void ExecuteAfterTestHooks(object testClass)
{
ExecuteHooks(testClass, typeof(AfterTestAttribute));
}
private MethodInfo[] GetHookMethods(object currentTestClass, Type attributeType)
{
return currentTestClass
.GetType()
.GetMethods()
.Where(m => m.GetCustomAttributes(attributeType, false).Length > 0)
.ToArray();
}
private void ExecuteHooks(object testClass, Type requiredAttributeType)
{
var hooks = GetHookMethods(testClass, requiredAttributeType);
var testCategories = GetTestCategories();
foreach (var hook in hooks)
{
var allAttributes = hook.GetCustomAttributes(requiredAttributeType, true);
foreach (var attribute in allAttributes)
{
if (!attribute.GetType().IsEquivalentTo(requiredAttributeType))
{
continue;
}
var hookCategories = GetCategoriesFromAttribute(attribute);
// if we do not have specific category on hook
// or we have at least one same category on hook and test
if (!hookCategories.Any() || hookCategories.Intersect(testCategories).Any())
{
ExecuteHookMethod(testClass, hook);
}
}
}
}
private object[] GetTestCategories()
{
return TestContext.CurrentContext.Test.Properties["Category"].ToArray();
}
private void ExecuteHookMethod(object testClass, MethodInfo method)
{
var hookName = method.Name;
_log.Information($"Executing - '{hookName}' hook");
try
{
method.Invoke(testClass, Array.Empty<object>());
}
catch (Exception e)
{
_log.Error($"Executing of - '{hookName}' hook failed - {e}");
}
}
private string[] GetCategoriesFromAttribute(object attribute)
{
if (attribute is BeforeTestAttribute beforeTestAttribute)
{
return beforeTestAttribute.Categories;
}
if (attribute is AfterTestAttribute afterTestAttribute)
{
return afterTestAttribute.Categories;
}
throw new ArgumentException($"{attribute.GetType().FullName} - does not have categories");
}
}
I have solved this using the name of the test:
namespace TestProject
{
public class TestClass
{
// Test without TearDown
[Test]
public void Test1()
{
Assert.Pass("Test1 passed");
}
// Test with TearDown
[Test]
public void Test2()
{
Assert.Pass("Test2 passed");
}
[TearDown]
public void TearDown()
{
// Execute only after Test2
if (TestContext.CurrentContext.Test.Name.Equals(nameof(this.Test2)))
{
// Execute Test2 TearDown...
}
}
}
}
Or if you want to use the full name of Test2 (TestProject.TestClass.Test2) you can replace the line
if (TestContext.CurrentContext.Test.Name.Equals(nameof(this.Test2)))
by
if (TestContext.CurrentContext.Test.FullName.Equals(typeof(TestClass).FullName + "." nameof(this.Test2)))