I'm using the VS2012 built-in Fakes framework.
This design question is related to the following post: Unit test won't "cover" simple get method. (c#)
I'm not certain how to design class for "IDbAccess" to successfully "fake" hitting the database.
Ex code (taken from previous post):
public class Foo : IFoo
{
IDbAccess db;
public Foo(IDbAccess db)
{
this.db = db;
}
public Dictionary<string,string> GetSomething(string xyz)
{
var result = new Dictionary<string,string>
db.commandText = "text..."
db.connection = conn;
result.Add(db.MethodWhatever(xyz));
return result;
}
}
Ex Test Method:
[TestMethod()]
public void GetSomething()
{
var dba = new StubIDbAccess();
var target = new Foo(dba);
var expected = new Dictionary<string, string>
{
{"blahKey","blahValue"}
};
// get something
var results = target.GetSomething("xyzstring");
// verify results
var actual = results.whatever;
CollectionAssert.AreEqual(expected,actual);
}
In order to "stub" IDbAccess, IDbAccess needs to be a class that inherits from IDbCommand. I'm just not sure how to implement it to avoid having to override everything in IDbCommand.
public interface IDbAccess : IDbCommand
{
...?
}
Related
I'm developing an API which communicates with MongoDB and I need to create some statistics from one collection. I have the following service:
public class BoxService : IBoxService
{
private readonly IMongoCollection<Box> _boxCollection;
public BoxService(IOptions<DbSettings> dbSettings, IMongoClient mongoClient)
{
var mongoDatabase = mongoClient.GetDatabase(dbSettings.Value.DatabaseName);
_boxCollection = mongoDatabase.GetCollection<Box>(dbSettings.Value.BoxCollectionName);
}
public async Task<List<BoxStatisticsDto>> GetBoxNumberStatisticsAsync()
{
var boxNumberStatisticsList = new List<BoxStatisticsDto>();
var results = await _boxCollection.AsQueryable()
.Select(box => new { box.WarehouseId, Content = box.Content ?? string.Empty })
.ToListAsync();
// More calculations with the results list
return boxNumberStatisticsList;
}
}
And the following test:
public class BoxServiceTest
{
private readonly IMongoCollection<Box> _boxCollection;
private readonly List<Box> _boxes;
private readonly IBoxService _boxService;
public BoxServiceTest()
{
_boxCollection = A.Fake<IMongoCollection<Box>>();
_boxes = new List<Box> {...};
var mockOptions = A.Fake<IOptions<DbSettings>>();
var mongoClient = A.Fake<IMongoClient>();
var mongoDb = A.Fake<IMongoDatabase>();
A.CallTo(() => mongoClient.GetDatabase(A<string>._, default)).Returns(mongoDb);
A.CallTo(() => mongoDb.GetCollection<Box>(A<string>._, default)).Returns(_boxCollection);
_boxService = new BoxService(mockOptions, mongoClient);
}
}
This is working so far, the BoxService is created with the fake parameters and I can test other functionalities of the service (FindAll, FindById, Create, etc.) but how can I test the GetBoxNumberStatisticsAsync function? I can't fake the AsQueryable because it's an extension method.
As you've noted, you can't fake an extension method. This question is asked every once in a while. For example, see Faking an Extension Method in a 3rd Party Library. There are a few approaches:
if the static method is simple enough, to divine what it does and fake the non-static methods that it calls
add a layer of indirection: wrap the call to the extension method in an interface that you can fake
don't fake the database. Instead, replace it with some in-memory analogue, if one exists (I don't know what's available for Mongo)
Here is what I ended up with. A base interface for all my services:
public interface IBaseService<T>
{
//generic method definitions for all services: Findall, FindById, Create, Update
}
An abstract class to have a generic constructor:
public abstract class BaseService<T> : IBaseService<T>
{
protected BaseService(IOptions<DbSettings> dbSettings, IMongoClient mongoClient, string collectionName)
{
var mongoDatabase = mongoClient.GetDatabase(dbSettings.Value.DatabaseName);
Collection = mongoDatabase.GetCollection<T>(collectionName);
}
protected IMongoCollection<T> Collection { get; }
// abstract method definitions for IBaseService stuff
public virtual async Task<List<T>> CollectionToListAsync()
{
return await Collection.AsQueryable().ToListAsync();
}
}
An interface for my BoxService:
public interface IBoxService : IBaseService<Box>
{
public Task<List<BoxStatisticsDto>> GetBoxNumberStatisticsAsync();
}
The service itself:
public class BoxService : BaseService<Box>, IBoxService
{
public BoxService(IOptions<DbSettings> dbSettings, IMongoClient mongoClient)
: base(dbSettings, mongoClient, dbSettings.Value.BoxCollectionName)
{
}
public async Task<List<BoxStatisticsDto>> GetBoxNumberStatisticsAsync()
{
var boxNumberStatisticsList = new List<BoxStatisticsDto>();
var list = await CollectionToListAsync();
var results = list.Select(box => new { box.WarehouseId, Content = box.Content ?? string.Empty }).ToList();
//...
return boxNumberStatisticsList;
}
}
And finally the test:
public async Task GetBoxNumberStatisticsAsync_ReturnsStatistics()
{
// Arrange
var expected = new List<BoxStatisticsDto> {...};
var fakeService = A.Fake<BoxService>(options => options.CallsBaseMethods());
A.CallTo(() => fakeService.CollectionToListAsync()).Returns(_boxes);
// Act
var boxList = await ((IBoxService)fakeService).GetBoxNumberStatisticsAsync();
// Assert
}
I'm not a huge fan of making the CollectionToListAsync public, but nothing really worked for me here. I tried creating IQueryable and IEnumerable from my list and convert them to IMongoQueryable but no success. I also tried faking the IMongoQueryable but I couldn't execute the Select on it as it gave an error that the 'collectionNamespace' can't be null and the CollectionNamespace can't be faked, because it's a sealed class.
I am trying to write some tests for an existing service we have. It uses the DbContext (In our case, named DatabaseContext) and the constructor looks like this:
public GenericOrderProvider(DatabaseContext context, IOrderHandler<T> orderHandler)
{
_orderHandler = orderHandler;
_context = context;
_dbSet = context.Set<T>();
}
As you can see, it's generic and sets the _dbSet when it's initialized.
I have this very simple method:
public Attempt<IQueryable<T>> List(params string[] includes)
{
var x = _dbSet.ToList();
return Attempt<IQueryable<T>>.Succeed(_dbSet.OrderBy(m => m.Order));
}
And I wrote this test:
[TestFixture]
public class ListShould
{
[Test]
public void ReturnList()
{
// Assemble
var services = GenericOrderProviderContext.GivenServices();
var provider = services.WhenCreateOrderProvider();
services.DatabaseContext.Set<Attribute>().ReturnsForAnyArgs(new List<Attribute>().ToDbSet());
//services.DatabaseContext.Attributes = new List<Attribute>().ToDbSet();
// Act
var result = provider.List();
// Assert
result.Failure.Should().BeFalse();
result.Result.Count().Should().Be(0);
}
}
When I run that test, I get the error:
NSubstitute.Exceptions.CouldNotSetReturnDueToNoLastCallException : Could not find a call to return from.
The trace specifically targets the line services.DatabaseContext.Set<Attribute>().ReturnsForAnyArgs(new List<Attribute>().ToDbSet()); but I have no idea how to fix it.
As far as I can tell, I am mapping to the right method.
For completeness, here is my test Contexts:
public class GenericOrderProviderContext: DatabaseContextContext<GenericOrderProviderContext>
{
public static GenericOrderProviderContext GivenServices() => new GenericOrderProviderContext();
public IGenericOrderProvider<Attribute> WhenCreateOrderProvider() =>
new GenericOrderProvider<Attribute>(DatabaseContext,
new OrderHandler<Attribute>(DatabaseContext));
public bool IsSequential(List<Attribute> models)
{
return !models.OrderBy(m => m.Order).Select(m => m.Order).Select((i, j) => i - j).Distinct().Skip(1).Any();
}
}
public class DatabaseContextContext<T> where T: DatabaseContextContext<T>
{
public DatabaseContext DatabaseContext;
protected DatabaseContextContext()
{
DatabaseContext = Substitute.For<DatabaseContext>();
}
}
Does anyone know what I can do to resolve this issue?
I created Test for a method that is being tested using MOQ & NUnit. The method to be tested will will another method using an object of that corresponding class. When I try to mock that called method, I am not able to invoke the mocked method. How to mock this method, because my testing method is using the other said method. Please help me on this.
public DataSet ExecuteCondition()
{
var ObjClass1 = new Class1();
....
var result = ObjClass1.VerifyPrecondition(query);
....
}
public class Class1:IClass1
{
public string VerifyPrecondition(string query)
{
....
return text;
}
}
So, I suppose this should look like this:
Class with ExecuteCondition() method:
public class DataClass
{
private readonly IClass1 _class1;
public DataClass(IClass1 class1)
{
_class1 = class1;
}
public DataSet ExecuteCondition()
{
//....
var result = _class1.VerifyPrecondition(query);
//....
}
}
Test:
[Test]
public void Test()
{
var mockClass1 = new Mock<IClass1>();
mockClass1.Setup(x => x.VerifyPrecondition(It.IsAny<string>())).Returns("test");
var dataClass = new DataClass(mockClass1.Object);
dataClass.ExecuteCondition();
//Assert
}
I assumed that MOQ would automatically create Mocks for any nested dependencies.
I am unit testing an ASP.Net MVC Controller:
public class TransactionController : Controller
{
private readonly ITransactionService _transactionService;
private readonly SearchPanelVmBuilder _searchPanelVmBuilder;
private readonly TransactionVmsBuilder _transactionVmsBuilder;
public TransactionController(TransactionVmsBuilder transactionVmsBuilder, ITransactionService transactionService, SearchPanelVmBuilder searchPanelVmBuilder)
{
_transactionVmsBuilder = transactionVmsBuilder;
_transactionService = transactionService;
_searchPanelVmBuilder = searchPanelVmBuilder;
}
// other methods omitted for brevity
public PartialViewResult SearchPanel()
{
var vm = _searchPanelVmBuilder.BuildVm();
return PartialView("_SearchPanel", vm);
}
}
The unit test code:
[Fact]
public void SeachPanel_Calls_BuildSearchPanelVm()
{
// Arrange
var mockTransService = new Mock<ITransactionService>();
var mockTransVmsBuilder = new Mock<TransactionVmsBuilder>();
var mockSearchPanelVmBuilder = new Mock<SearchPanelVmBuilder>();
var controller = new TransactionController(mockTransVmsBuilder.Object, mockTransService.Object, mockSearchPanelVmBuilder.Object);
// Act
controller.SearchPanel();
// Assert
mockSearchPanelVmBuilder.Verify(x => x.BuildVm());
}
MOQ complains:
Can not instantiate proxy of class: MCIP.Web.UI.ViewModelBuilders.Singular.SearchPanelVmBuilder.
Could not find a parameterless constructor.
The class it can't instantiate a proxy for:
public class SearchPanelVmBuilder
{
private readonly ITransactionTypeService _transactionTypeService;
private readonly TransactionTypeVmBuilder _transactionTypeVmBuilder;
private readonly UserProvider _userProvider;
public SearchPanelVmBuilder(
UserProvider userProvider,
ITransactionTypeService transactionTypeService,
TransactionTypeVmBuilder transactionTypeVmBuilder
)
{
_userProvider = userProvider;
_transactionTypeService = transactionTypeService;
_transactionTypeVmBuilder = transactionTypeVmBuilder;
}
public virtual SearchPanelVm BuildVm()
{
return new SearchPanelVm
{
Userlist = _userProvider.GetOperators(),
TransactionTypes =
_transactionTypeService.GetAll().Select(x => _transactionTypeVmBuilder.BuildVmFromModel(x)).ToList()
};
}
}
Its corresponding dependencies:
public class UserProvider
{
private static int retryCount;
public virtual List<string> GetOperators()...
public virtual List<string> GetGroupsForUser(WindowsIdentity identity)...
}
public interface ITransactionTypeService
{
List<TransactionType> GetAll();
}
public class TransactionTypeVmBuilder
{
public virtual TransactionTypeVm BuildVmFromModel(TransactionType transactionType)...
}
Am I doing something wrong?
Do I have to explicitly tell MOQ to have a go at auto-mocking nested dependencies?
Or do i have to explicitly set up the nested Mocks - like this:
var mockUserProvider = new Mock<UserProvider>();
var mockTransTypeService = new Mock<ITransactionTypeService>();
var mockTransactionTypeVmBuilder = new Mock<TransactionTypeVmBuilder>();
var mockSearchPanelVmBuilder = new Mock<SearchPanelVmBuilder>(mockUserProvider.Object, mockTransTypeService.Object, mockTransactionTypeVmBuilder.Object);
Yes your assumption is correct. Because the class SearchPanelVmBuilder haven't provided parameterless constructor Mock for this class can't be created like this:
var mockSearchPanelVmBuilder = new Mock<SearchPanelVmBuilder>()
Causes exception: Could not find a parameterless constructor.
Instead create the Mock by providing all the parameters, something like this:
UserProvider userProvider = new UserProvider();
Mock<ITransactionTypeService> transactionTypeService = new Mock<ITransactionTypeService>();
TransactionTypeVmBuilder transactionTypeVmBuilder = new TransactionTypeVmBuilder();
// Use constructor with parameters here because SearchPanelVmBuilder
// doesn't have parameterless constructor
var mockSearchPanelVmBuilder = new Mock<SearchPanelVmBuilder>(
userProvider, transactionTypeService.Object, transactionTypeVmBuilder);
var mockTransService = new Mock<ITransactionService>();
var mockTransVmsBuilder = new Mock<TransactionVmsBuilder>();
var controller = new TransactionController(
mockTransVmsBuilder.Object,
mockTransService.Object,
mockSearchPanelVmBuilder.Object);
Then the instance of the controller TransactionController can be created and the method SearchPanel can be called on it.
In this case, all you want to test is that BuildVM is called and the result is returned so you don't need to mock the inner dependencies. You do need to setup a return value for the BuildVM method in the Arrange section before you call the SearchPanel method.
mockSearchPanelVmBuilder.Setup(x => x.BuildVM()).Returns(mockSearchPanelVM);
Because your mocking a class and virtual method if you don't setup a return value the actual implementation will be run. With an interface an error will be thrown that indicated you should setup a return value.
I'm currently trying to implement StructureMap's AutoMocking functionality and I need help with getting the mocked .
I have a Test method as follows:
[Test]
public void DirctoryResult_Returns_Groups()
{
var autoMocker = new RhinoAutoMocker<GroupController>(MockMode.AAA);
GroupController controller = autoMocker.ClassUnderTest;
var directoryResult = controller.DirectoryResult("b");
var fundDirectoryViewModel = (FundDirectoryViewModel)directoryResult.ViewData.Model;
Assert.IsNotNull(fundDirectoryViewModel.Groups);
}
Currently the test is failing because fundDirectoryViewModel.Groups is null.
The real implementation of DirectoryResult is as follows:
private readonly IGroupService _groupService;
public PartialViewResult DirectoryResult(string query)
{
return PartialView(new FundDirectoryViewModel
{
Groups =_groupService.GetGroupsByQuery(query)
});
}
where _groupService.GetGroupsByQuery(query) uses an interface to IGroupRepository to read data from the database. Of course, I don't want my test to read data from the actual database, but can somebody tell me how to get mock data for it?
What do I need to do to get the AutoMocker to mock the fake data for me?
update:
for reference, this is the definition of GroupService & GroupRepository
public class GroupService : IGroupService
{
private readonly IGroupRepository _groupRepository;
public GroupService(IGroupRepository groupRepository)
{
_groupRepository = groupRepository;
}
public IList<CompanyGroupInfo> GetGroupsByQuery(string query)
{
return _groupRepository.GetGroupsByQuery(query);
}
}
public class GroupRepository : DataUniverseRepository, IGroupRepository
{
public GroupRepository(ISession session)
{
_session = session;
}
public IList<CompanyGroupInfo> GetGroupsByQuery(string query)
{
// dig into the database and return stuff with _session..
}
}
I've been informed that the question was wrong. Automocker doesn't mock data like that. It's up to me to specify the fake data with Rhino Mocks.
This works:
[Test]
public void DirctoryResult_Returns_Groups()
{
var service = autoMocker.Get<IGroupService>();
service.Expect(srv => srv.GetGroupsByQuery(Arg<string>.Is.Anything))
.Return(new List<CompanyGroupInfo>
{
new CompanyGroupInfo(),
new CompanyGroupInfo(),
new CompanyGroupInfo()
});
service.Replay();
var directoryResult = _controller.DirectoryResult("b");
var fundDirectoryViewModel = (FundDirectoryViewModel)directoryResult.ViewData.Model;
Assert.That(fundDirectoryViewModel.Groups.Count, Is.EqualTo(3));
service.AssertWasCalled(srv => srv.GetGroupsByQuery(Arg<string>.Is.Equal("b")));
}