Unit test difference in mock and real object - c#

Below is my unit test method(c#) :-
[TestMethod]
public void ShouldReturnDtosWhenProductsFound_GetProducts()
{
// Arrrange
var count = 0;
var name = "myproduct";
var description = "desc";
// setup mocked dal to return list of products
// when name and description passed to GetProducts method
_productDalMock.Setup(d => d.GetProducts(name, description)).Returns(_productList);
// Act
List<ProductDto> actual = _productService.GetProducts(name, description);
// Assert
Assert.IsNotNull(actual);
Assert.IsTrue(actual.Any());
Assert.AreEqual(_productList.Count, actual.Count);
foreach (var product in _productList)
{
Adapter.AssertAreEqual(product, actual[count]);
count++;
}
// verify all setups of mocked dal were called by service
_productDalMock.VerifyAll();
}
I am using Mock object to mocking the GetProducts method(dependency).And in mocking i am returning the already declared product list(_productList).
My problem is when i am debugging the test,i am not getting the same product list in actual object as i passed in mocking.And according to my exploration we will get the same list of objects in actual result which we pass in mock object.
Can any one suggest me what is going wrong here ?
Edit
I just want to know its necessary for mock object to return the same values with actual object or it can be change ?

When you initialize _productService, inject the _productDalMock you're setting up. This is typically done in the constructor of _productService, after you have initialized the _productDalMock instance.
_productService = new ProductService(_productDalMock);
In your debugging, verify that the _productService.GetProducts code finally hits the _productDal.GetProducts code line. i.e. there is no code before the DAL call which would make the _productService.GetProducts method return etc.
If you ensure the above 2 steps, then the actual products returned should be same as the one you're passing.

Related

How to mock a method inside the same class being tested?

I am creating some unit tests for a method ValidateObject in a service ObjectService. The ValidateObject method calls another method ValidateObjectPropertyB. I want to mock the calls to the last method.
The ObjectService and relevant method look like this:
public class ObjectService : IObjectService
{
public bool ValidateObject(object objectToValidate)
{
return
!String.IsNullOrEmpty(objectToValidate.PropertyA) &&
ValidateObjectPropertyB(objectToValidate.PropertyB, currentUserId);
}
public bool ValidateObjectPropertyB(long propertyB, long userId)
{
return validationResult;
}
}
Right now my Test class ObjectServiceTest contains the following code:
public class ObjectServiceTest
{
var objectToValidate = new Object(validPropertyA, validPropertyB);
using(var mock = new AutoMock.GetStrict())
{
var mockObjectService = new Mock<IObjectService>();
mockObjectService.callBase = true;
mockObjectService.Setup(s => s.ValidateObjectPropertyB(objectToValidate.PropertyB, _user.Id)).Returns(true);
var service = mock.Create<ObjectService>();
var result = service.ValidateObject(objectTovalidate);
Assert.IsTrue(result);
}
}
The above test fails because result is false, the for PropertyA succeeds
What am I doing wrong?
ValidateObject works in part by calling ValidateObjectPropertyB. I am presuming you are wanting to mock this second method so that you can demonstrate that ValidateObject does indeed call ValidateObjectPropertyB (provided !String.IsNullOrEmpty(objectToValidate.PropertyA) evaluates to true)
If this is the case then you are testing implementation detail, which generally you shouldn't do. Consider a function that took two integer values and returned their sum, you would want to verify that when this function was passed 3 and 5 it returned 8, you should not test that it arrived at this answer by using a particular method/class under the hood because this is not relevant to the desired outcome and should in future you decide you wished to refactor your code the test would likely start failing even if the code still returned the desired result.
Looking at your code, it seems that return value of ValidateObject is not directly dependent on the method call to ValidateObjectPropertyB but rather the value of validationResult. It is this value that you must set to properly test ValidateObject.
One way to achieve what you are asking would be to make ValidateObjectPropertyB virtual, then create a derived class that overrides this method to return what ever you want. However I do not recommend doing this purely for the sake of unit testing.

Moq Unit Testing - expected result?

I'm using Moq for my Unit Tests and have got the following method:
[TestMethod]
public void GetTestRunById_ValidId_TestRunReturned()
{
var mockTestRunRepo = new Mock<IRepository<TestRun>>();
var testDb = new Mock<IUnitOfWork>();
testDb.SetupGet(m => m.TestRunsRepo).Returns(mockTestRunRepo.Object);
TestRun returnedRun = EntityHelper.getTestRunByID(testDb.Object, 1);
}
The method in question which is being tested is getTestRunByID(). I have confirmed that this method is called when debugging this unit test, but as expected getTestRunByID() doesn't return anything since the mock has no data inside it.
Would all that matter is the method gets hit and returns null? If not, how can I add data to my mockTestRunRepo when it's only present as a returned value from testDb?
For reference the method being tested is:
public static TestRun getTestRunByID(IUnitOfWork database, int testRun)
{
TestRun _testRun = database.TestRunsRepo.getByID(testRun);
return _testRun;
}
The purpose of the unit test is to ONLY test the small method getTestRunByID. For that, test if it was called exactly once with that integer parameters, 1.
mockTestRunRepo.Verify(m => m.getByID(1), Times.Once());
You must also set up the method getByID for mockTestRunRepo, to make it return a specific value, and test if the result value of the test run is equal to what you expected.
//instantiate something to be a TestRun object.
//Not sure if abstract base class or you can just use new TestRun()
mockTestRunRepo.Setup(m => m.getByID(1)).Returns(something);
Test if you get the same value
TestRun returnedRun = EntityHelper.getTestRunByID(testDb.Object, 1);
Assert.AreEqual(returnedRun, something);
This code might be prone to errors, as I do not have an environment to test it right now. But this is the general idea behind a unit test.
This way, you test if the method getById runs as expected, and returns the expected result.
You have your repository return data the same way that you setup everything else.
var mockTestRunRepo = new Mock<IRepository<TestRun>>();
// This step can be moved into the individual tests if you initialize
// mockTestRunRepo as a Class-level variable before each test to save code.
mockTestRunRepo.Setup(m => m.getById(1)).Returns(new TestRun());
Per #Sign's recommendation, if you know that you're calling it with 1, then use that instead of It.IsAny<int>() to keep things cleaner.

Assert that method was called in a unit test

I want to assert that a call on my real object (system under test) was called. Here is my test
// Arrange
var contextFactory = A.Fake<IContextFactory>();
var db = A.Fake<IDatabase>();
A.CallTo(() => contextFactory.GetContext()).Returns(db);
var vm = new MainViewModel(contextFactory);
// Act
vm.Loaded();
// Assert
A.CallTo(() => vm.LoadModels(db)).MustHaveHappened();
I'm getting an ArgumentException that says "The specified object is not recognized as a fake object." How do I test that the LoadModels() method in my MainViewModel gets called from the Loaded() method?
EDIT
The reason I'm doing it this way is because the Loaded() method calls a bunch of other methods when the app starts and I don't want to have to setup all the other stuff for each test, I just want to make sure that all the proper methods get called and then test them individually. I'm open to suggestion for a better way of going about this.
Here are the Loaded and LoadModels methods
internal virtual void Loaded()
{
using (var db = _contextFactory.GetContext())
{
LoadModels(db);
// bunch of other method calls
}
}
internal virtual void LoadModels(IDatabase db)
{
Models = new ObservableCollection<Model>(db.Models);
}
It looks like you're verifying a method (vm.LoadModels) that isn't part of the fake (db). You can only verify methods on a fake, not methods that happen to take the fake as an argument.
I ended up moving the functionality of LoadModels() to another class that implements IStartupDataLoader and then I was able to test it like this
// Arrange
var sdl = A.Fake<IStartupDataLoader>();
var exp = A.Fake<ObservableCollection<Model>>();
A.CallTo(() => sdl.LoadModels()).Returns(exp);
var sut = new MainViewModel(sdl);
// Act
sut.Loaded();
// Assert
Assert.That(exp == sut.Models);

What is the correct way to test this code using MOQ?

I have the following method:
public void MoveChannelUp(string channelName)
{
var liveChannels = _repository.GetChannels<LiveChannel>();
var channels = GetModifiedChannelsList(channelName, liveChannels);
_repository.SaveChannels(channels);
}
I want to set up an expectation on the SaveChannels() call so that the correct channels parameter is passed in.
I tried :
channelsRepository.Setup(x => x.SaveChannels(reorderedChannels));
where reorderedChannels is what I expect the GetModifiedChannelsList() call will return and but I got Mock verification exception (probably due to reorderedChannels is not the same object as channels???)
So it is GetModifiedChanneslsList() which I really want to test (I know I can use reflection to test this)
So how do I test the correct channels list is passed to SaveChannels()?
You can do something like this (I assume there is a type called Channel and the parameter for SaveChannels is List<Channel>; substitute with the actual):
var expectedChannels = new List<Channel> { new Channel() }; // set up expected channels here
var channelsRepo = new Mock<IChannelsRepository>();
// perform your unit test using channelsRepo here, for example:
channelsRepo.Object.SaveChannels(new List<Channel> { new Channel() });
channelsRepo.Verify(x => x.SaveChannels(It.Is<List<Channel>>(l => l.SequenceEqual(expectedChannels)))); // will throw an exception if call to SaveChannels wasn't made, or the List of Channels params did not match the expected.
What this code does is verify that the SaveChannels method is called at least once with the right list of channels. If that does not happen, Verify will throw an exception and your unit test will fail as expected.

how to interpret this (rhino) mock unit test failure msg

I am trying to test that a method to load a UI matrix is being loaded properly. The test fails unless I tell the mock framework to ignore the argument passed, giving me the following message:
Rhino.Mocks.Exceptions.ExpectationViolationException :
ITimeSheetMatrixWidget.Load
(Smack.ConstructionAdmin.Domain.TransferObjects.TimeSheetDtoAssembler
+d__1); Expected #1, Actual #0.
What is interesting is that the message is somehow picking up a call made to another object that assembles DTOs from the domain model - I don't get it!
Here is the interface / method Sut is:
public interface ITimeSheetMatrixWidget : IMatrixWidget {
.....
void Load(IEnumerable<DynamicDisplayDto>activities);
.....
}
And here is the test:
[Test]
public void SettingTheWidget_TriggersLoad_NonProjectActivities() {
var f = _getFacade();
// create test activities
TestDataFactory.SetupTestActivities(f);
Assert.That(f.NonProjectDtos.Count(), Is.GreaterThan(0));
// create the presenter
var filterService = MockRepository.GenerateStub<IProjectFilterService>();
var view = MockRepository.GenerateStub<ITimeSheetView>();
var timeSheetPresenter = new TimeSheetPresenter(f, filterService, view);
// inject the mocked widget & trigger the Load
var widget = MockRepository.GenerateMock<ITimeSheetMatrixWidget>();
timeSheetPresenter.ActivityMatrix = widget;
widget.AssertWasCalled(x => x.Load(f.NonProjectDtos),
mo =>mo.IgnoreArguments()); <-- ok, but not useful
//widget.AssertWasCalled(x => x.Load(f.NonProjectDtos)); <-- generates the Exception
}
Can someone explain the failure message?
As an aside, I did post this on the Rhino Mocks forum this morning but traffic there looks like it is very low.
Thank you for your help!
Berryl
Rhino was stating the fact that the way the test was laid out, I wasn't getting the call I'd told it to expect. The test below is an effective way to test an IEnumerable argument:
[Test]
public void ProjectMatrix_Injection_IsLoaded()
{
_projectMatrix = MockRepository.GenerateMock<ITimeSheetMatrixWidget>();
var dtos = _facade.ProjectDtos;
_projectMatrix.Expect(x => x.Load(Arg<IEnumerable<DynamicDisplayDto>>.List.Equal(dtos))).Return(dtos.Count());
new MatrixEntryService(_facade, _projectMatrix, _nonProjectMatrix, _totalMatrix);
_projectMatrix.VerifyAllExpectations();
}
The first trick is using the Rhino argument constraints:
Arg<IEnumerable<DynamicDisplayDto>>
The second trick is to use the List extension, instead of Is:
List.Equal(dtos)
I think it expected one call but got none.

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