I'm trying to use FakeItEasy (version 4.9.1) to create unit tests for some legacy code. I've created two unit tests, one of which works just as expected, and one very similar which doesn't work despite lots of trial and error.
Here's an excerpt from the method that seems impossible to test:
public class PosMessageProcessor : IPosMessageProcessor
{
public void Execute()
{
PurchaseOrderRepository repo = new PurchaseOrderRepository();
...
try
{
m_PurchaseOrder = GetOrderForProcessing(repo);
...
And here's my test:
[TestMethod]
[TestCategory("POS")]
public void ExecuteTest()
{
// Arrange
PurchaseOrder purchaseOrder = GetPurchaseOrder();
IPosMessageProcessor fakePosMessageProcessor = A.Fake<IPosMessageProcessor>();
A.CallTo(() => fakePosMessageProcessor.GetOrderForProcessing(A<IPurchaseOrderRepository>.Ignored)).Returns(purchaseOrder);
// Act
_posMessageProcessor.Execute();
// Assert
A.CallTo(() => fakePosMessageProcessor.GetOrderForProcessing(A<IPurchaseOrderRepository>.Ignored)).MustHaveHappened();
}
The _posMessageProcessor variable is an instance of the PosMessageProcessor class. I want to catch the call to the GetOrderForProcessing() method (within the Execute() method) and make it return my hard-coded purchaseOrder object. But I get another return value (null) instead. Why?
The unit test that works tests the GetOrderForProcessing() method:
[TestMethod]
[TestCategory("POS")]
public void GetOrderForProcessingTest()
{
// Arrange
PurchaseOrder purchaseOrder = GetPurchaseOrder();
IPurchaseOrderRepository fakePurchaseOrderRepository = A.Fake<IPurchaseOrderRepository>();
A.CallTo(() => fakePurchaseOrderRepository.GetPurchaseOrderByOrderTrackingNumber(A<string>.Ignored)).Returns(purchaseOrder);
// Act
PurchaseOrder result = _posMessageProcessor.GetOrderForProcessing(fakePurchaseOrderRepository);
// Assert
A.CallTo(() => fakePurchaseOrderRepository.GetPurchaseOrderByOrderTrackingNumber(A<string>.Ignored)).MustHaveHappened();
Assert.IsNotNull(result);
}
In this case, the call to GetPurchaseOrderByOrderTrackingNumber() returns my hard-coded object as expected. The two tests are virtually the same, except that the GetOrderForProcessing() method takes a parameter while Execute() does not.
ExecuteTest is failing because you configure a fake IPosMessageProcessor and then call Execute on a real PosMessageProcessor, _posMessageProcessor. _posMessageProcessor, being an actual PosMessageProcessor, executes its regular code path, calling the actual Execute, which will call the actual GetOrderForProcessing.
(Note that you can actually delete the fakePosMessageProcessor variable and all references to it from your test, and the behaviour will be the same.)
I do not recommend this kind of testing, but in order to fake GetOrderForProcessing and still test the actual Execute code, you would have to write a test like
public void NewExecuteTest()
{
// Arrange
PurchaseOrder purchaseOrder = GetPurchaseOrder();
// Get a fake PosMessageProcessor that falls back to original behaviour for all calls.
IPosMessageProcessor fakePosMessageProcessor = A.Fake<PosMessageProcessor>(options => options.CallsBaseMethods());
// Now fake out the GetOrderForProcessing call so we can test Execute.
A.CallTo(() => fakePosMessageProcessor.GetOrderForProcessing(A<IPurchaseOrderRepository>.Ignored)).Returns(purchaseOrder);
// Act
fakePosMessageProcessor.Execute();
// Assert
A.CallTo(() => fakePosMessageProcessor.GetOrderForProcessing(A<IPurchaseOrderRepository>.Ignored)).MustHaveHappened();
}
Related
I have a class that gets knockout messages using the method below:
public IEnumerable<Message> GetKnockoutMessages(Data data)
{
if(data.Messages != null)
{
return data.Messages.Where(m => m.UnderWritingRuleId != null);
}
else
{
return new List<Message>();
}
}
So far, i have a unit test that only partially covers the unit test which is below.
[TestMethod]
public void TestGetKnockoutMessages()
{
KnockoutUtility knockUtility = new KnockoutUtility();
IEnumerable<Message> messages = knockUtility.GetKnockoutMessages(MockData.Object);
Assert.IsNotNull(messages);
}
This covers everything but return data.Messages.Where(m => m.UnderWritingRuleId != null);
I was wondering how I would unit test this method to get 100% coverage.
Any help would be appreciated. Thanks
This unit test doesn't cover everything because you are not verifying all cases. You have to test two logics:
if/else logic
Where(m => m.UnderWritingRuleId != null) logic
Based on this assumption you have to create cases which proof following:
If data.Messages are null then you have to verify that method returns new instance of List<Message>() because you specified in code like that.
Next case will be to verify that method returns empty IEnumerable<Message> if data.Messages are empty (which means this condition data.Messages.Count() == 0).
Next case will be to verify that method returns exact messages which satisfied your condition: Where(m => m.UnderWritingRuleId != null). In other words only messages which have populated UnderWritingRuleId.
To achieve what I mentioned you have to create Data objects which satisfied this cases. I don't know what is MockData.Object but I hope that you included you arrangement there.
Each case should be in separate test method like in following:
[TestMethod]
public void TestGetKnockoutMessages_Case1()
{
// Arrange
// Action
// Assert
}
[TestMethod]
public void TestGetKnockoutMessages_Case2()
{
// Arrange
// Action
// Assert
}
[TestMethod]
public void TestGetKnockoutMessages_Case3()
{
// Arrange
// Action
// Assert
}
Arrange is place where you configuring your mock-ups. Action is place where you executing method which you want to test and Assert is place where you doing assertion.
I'm using FakeItEasy to do some testing, but I have run into a problem.
When testing that the expected data is sent to a faked service, I would like to be able to see the error data as well.
Right now I only see that the call never happened.
Maybe I'm setting it up all wrong, but then I'd like some hints on how to correct it. :)
My case is:
A call to the same service twice, with different values.
I want separate tests to verify each call.
If any of the parameters, doesn't have the expected value, I would like to get an error message stating that. Similar to when you do an Assert.AreEqual().
Right now I only get "Call did not happen", which is totally understandable, because I realise that is what I'm testing. But I would like to be able to verify that a specific call has only been made once, and if it did not happen I would like to see which values were used to not make it happen.
I used this solution: http://thorarin.net/blog/post/2014/09/18/capturing-method-arguments-on-your-fakes-using-fakeiteasy.aspx
when I only had one call, but with two calls it doesn't work.
[TestFixture]
public class TestClass
{
[Test]
public void TestOne()
{
// Arrange
var fake = A.Fake<IBarservice>();
var a = new Foo(fake);
// Act
a.DoStuff(1);
//Assert
A.CallTo(() => fake.DoOtherStuff(A<int>.That.Matches(x => x == 2))).MustHaveHappened(Repeated.Exactly.Once);
}
[Test]
public void TestTwo()
{
// Arrange
var fake = A.Fake<IBarservice>();
var a = new Foo(fake);
// Act
a.DoStuff(1);
//Assert
A.CallTo(() => fake.DoOtherStuff(A<int>.That.Matches(x => x == 3))).MustHaveHappened(Repeated.Exactly.Once);
}
}
public class Foo
{
private readonly IBarservice _barservice;
public Foo(IBarservice barservice)
{
_barservice = barservice;
}
public void DoStuff(int someInt)
{
someInt++;
_barservice.DoOtherStuff(someInt);
// I should have increased someInt here again, but this is a bug that my tests catches
_barservice.DoOtherStuff(someInt);
}
}
public interface IBarservice
{
void DoOtherStuff(int someInt);
}
Markus, I had a comment that I've redacted, since I made an error.
You say you only get "Call did not happen" and
… I would like to be able to verify that a specific call has only been made once, and if it did not happen I would like to see which values were used to not make it happen.
I fear I don't understand what information you were hoping for, since when I run TestOne, I get
FakeItEasy.ExpectationException
Assertion failed for the following call:
FakeItEasyQuestionsVS2015.IBarservice.DoOtherStuff(<x => (x == 2)>)
Expected to find it exactly once but found it #2 times among the calls:
1: FakeItEasyQuestionsVS2015.IBarservice.DoOtherStuff(someInt: 2) repeated 2 times
...
This says that the call DoOtherStuff was made twice, with someInt passed in as the value 2 each time.
I have to test a projection that handle a given events and persist it on a read only Mongo database (I'm using official c# Mongo Driver):
public class MyObjectProjection : IHandleMessages<RegisteredEvent>
{
private MongoCollection<MyObjectView> _collection;
private MyObjectView item;
public MyObjectProjection (MongoDatabase db)
{
_collection = db.GetCollection<MyObjectView>("my-object");
}
public void Handle(RegisteredEvent message)
{
item = new MyObjectView();
item.Id = message.Id;
// some code omitted
_collection.Save(item);
}
}
I need to unit test the Handle method, given that:
I don't want an integration test. Database and collection are mocked, so the save is not real
I just want to test the item-message mapping
the members are hidden and I don't want to make them more visibile
Should I use alternative solution rather than reflection or friendly assembly? What is the best practice in a case like this?
Right now my test look like this:
[TestMethod]
public void TestMethod1()
{
// ARRANGE - some code omitted
databaseMock
.Setup(x => x.GetCollection<MyObjectView>(It.IsAny<string>()))
.Returns(collection);
collectionMock
.Setup(x => x.Save(It.IsAny<MyObjectView>()))
.Returns(It.IsAny<WriteConcernResult>);
// ACT
var handler = new MyObjectProjection(database);
handler.Handle(evt);
// ASSERT
// nothin' to assert here!
}
this works, but i have nothing to assert when Handle method is completed.
What is the best practice in a case like this?
The best practice is to make members visible. Is there any particular reason why you need to hide members?
Then, you can assert against argument passed to Save method :
MyObjectView objectView;
collectionMock
.Setup(x => x.Save(It.IsAny<MyObjectView>()))
.Callback<MyObjectView>((obj) => objectView= obj)
.Returns(It.IsAny<WriteConcernResult>);
Assert.That(objectView.Id, Is.EqualTo(evt.Id));
//assert other properties
Well, your Handle() method interacts with the collection, by calling the Save() method. Therefore you can expect that the element passed to the Handle method has proper ID set:
collectionMock.Verify(x=>x.Save(It.Is<MyObjectView>(v => v.Id == 5)), Times.Once,"save should be called with object with Id = 5");
I assumed here that the evt that is passed into Handle() has and Id of 5. Code not tested, but I think something like that would do the trick.
I am trying to test a repository using MOQ to mock the behavior of the repo. I am failry new to MOQ, so bear with me please.
Given the following method:
public static SubmissionVersion DeleteNote(IRepository repository, SubmissionVersion version, Guid noteId)
{
Note note = repository.GetById<Note>(noteId);
version.Notes.Remove(note);
repository.Save(version);
repository.Delete(note);
return repository.GetById<SubmissionVersion>(version.Id);
}
Does this test look OK?
[Fact]
public void DeleteNoteV2()
{
// Arrange
var note = new Note{ Id = Guid.NewGuid()};
var subVersion = new Mock<SubmissionVersion>();
subVersion.Setup(x => x.Notes.Remove(note));
var repo = new Mock<IRepository>();
repo.Setup(x => x.GetById<Note>(note.Id)).Returns(note);
repo.Setup(x => x.GetById<SubmissionVersion>(It.IsAny<Guid?>())).Returns(subVersion.Object);
// Act
SubmissionVersion.DeleteNote(repo.Object, subVersion.Object, note.Id.Value);
// Assert
repo.Verify(x => x.GetById<Note>(note.Id), Times.Once());
repo.Verify(x => x.Save(subVersion.Object), Times.Once());
repo.Verify(x => x.Delete(note), Times.Once());
subVersion.Verify(x => x.Notes.Remove(It.IsAny<Note>()), Times.Once());
}
Your approach is good, however I would adjust few things. I have made few changes to your test and mocking components which you can see below.
Unit Test
You method under test within your Unit Test (see below), does not really match with the method which you have defined in your question.
Unit test method call:
SubmissionVersion.DeleteNote(repo.Object, subVersion.Object, note.Id.Value);
Method under test:
public static SubmissionVersion DeleteNote
(IRepository repository, SubmissionVersion version, Guid noteId)
I assume the above method is part of another class, I called it as NotesHelper - Not the ideal name for repository calls, but it is just to get the compilation working.
I would personally separate out your Unit test into 2 separate Unit tests. One to verify whether the required methods being called, and the other is to verify whether the notes have been removed from the collection.
Also instead of creating a mocked SubmissionVersion, I created a fakeSubmissionVersion.
This is because the routines within SubmissionVersion may not be mockable. You can also do a state based testing (preferred) to ensure the version.Notes.Remove(note); has been called.
[Fact]
public void DeleteNote_Deletion_VerifyExpectedMethodsInvokecOnlyOnce()
{
// Arrange
var note = new Note { Id = Guid.NewGuid() };
var fakeSubmissionVersion = new SubmissionVersion() { Notes = new List<Note>() };
var repo = new Mock<IRepository>();
repo.Setup(x => x.GetById<Note>(It.IsAny<Guid>())).Returns(note);
// Act
NotesHelper.DeleteNote(repo.Object, fakeSubmissionVersion, note.Id.Value);
// Assert
repo.Verify(x => x.GetById<Note>(note.Id), Times.Once());
repo.Verify(x => x.Save(fakeSubmissionVersion), Times.Once());
repo.Verify(x => x.Delete(note), Times.Once());
}
The above test can be further improved by defining each Verification in its own test.
[Fact]
public void DeleteNote_Deletion_VerifyDeleteMethodCalledOnlyOnce()
This way if one the test fails we would know exactly which method has not been called with the expectation. Sometimes, having multiple verifications as above can be problematic. For example, if the Save method has not been called, you would never know the Delete method has been called or not. This is because the exception has been thrown when the Save method has not been called and the test execution has been terminated.
This would result in multiple tests but they are more readable and maintainable. Of course you can refactor the common code into a factory or helper method.
[Fact]
public void DeleteNote_RemoveNotes_ReturnsExpectedNotes()
{
// Arrange
var note = new Note { Id = Guid.NewGuid() };
var fakeSubmissionVersion = new SubmissionVersion() { Notes = new List<Note>() { note } };
var repo = new Mock<IRepository>();
repo.Setup(x => x.GetById<Note>(It.IsAny<Guid>())).Returns(note);
// Act
NotesHelper.DeleteNote(repo.Object, fakeSubmissionVersion, note.Id.Value);
// Assert
Assert.AreEqual(0, fakeSubmissionVersion.Notes.Count);
}
Additional Note: Also providing a descriptive Unit test method names improves the readability of the Unit Tests.
I've been using Moq for the past week or so and haven't had any issues until today. I'm having a problem with getting VerifyAll() to properly match the setup of my mock.
I'm currently writing unit tests for my application's API. Here's how the application is structured:
API <==> Service <==> DAO <==> Database
With this in mind, I'm mocking the service object and then constructing an API object using the mocked service. I've written a number of unit tests already without problem up until now.
I have two instance variables like this:
private Api _api;
private Mock<IHibernateService> mockService;
I initialize these in a setup method:
[SetUp]
public void DoSetupTasks()
{
mockService = new Mock<IHibernateService>();
_api = new Api(mockService.Object);
}
Here is the unit test that is failing:
[Test]
public void TestSearchOnAllProperties()
{
mockService
.Setup(service => service.LoadAll(It.IsAny<Type>()))
.Returns(new DomainBase[0]);
var dmbs = _api.SearchOnAllProperties("search term", typeof(DomainBase));
mockService.VerifyAll();
}
The API's SearchOnAllProperties() method will subsequently make a call to the service's LoadAll() method (with some additional logic of course), so I want to verify that it's being called properly. To clarify, here's how LoadAll() is being called in SearchOnAllProperties():
public IEnumerable<DomainBase> SearchOnAllProperties(string searchTerm, Type type)
{
foreach (DomainBase dmb in _hibernateService.LoadAll(type))
{
// additional logic
}
}
However, when I run the unit test, I get a MockVerificationException stating that the given setup was not matched. I cannot figure out why as it should be calling the service's LoadAll() method.
One possible cause is that at some point before this particular test method is called, mockService is being assigned to a new instance of Mock<IHibernateService>. If that is the case, then this test method would be calling Setup on the wrong instance, which would then produce this exception.
A quick way to test this would be to use local mockService and api variables and see if the test still fails:
[Test]
public void TestSearchOnAllProperties()
{
var localMockService = new Mock<IHibernateService>();
var localApi = new Api(localMockService.Object);
localMockService
.Setup(service => service.LoadAll(It.IsAny<Type>()))
.Returns(new DomainBase[0]);
var dmbs = localApi.SearchOnAllProperties("search term", typeof(DomainBase));
localMockService.VerifyAll();
}
HTH