I want to write an integration test using a real repository but also verify behavior of the repository
SomeService(IRepository r) calls r.QuerySomething()
And I've been trying to achieve this using Moq:
var mock = new Mock<IRepository >(() => new Repository());
mock.CallBase = true;
The trouble is that it never calls methods from Repository nor does it call it's constructor. The lambda over there is meant for getting ctor parameters (if type is a class) not for object initialization.
Q: How do I wrap new Repository() into a Mock<IIRepository> so I can verify calls?
NB: it works if the type give is a class but I cannot then use it for verifying since they implementatin is not virtual.
Alternatively is there some other nuget that can help me achieve this?
There is a technique that I use for testing brownfiled legacy code, it can probably help, in what you're trying to achieve. You can introduce a decorator into your tests project that wraps your original implementation, but also implements the IRepository interface.
class TestRepository : IRepostiory
{
public TestRepository(Repository next)
{
this.next = next;
}
}
Inside this class you can declare all the interface members as virtual.
class TestRepository : IRepostiory
{
public virtual IReadOnlyList<Client> GetByName(string name)
{
return this.next.GetByName(name);
}
}
Now you can use the TestRepository in place of your original implementation and also create a mock that verifies the calls to this class.
var repository = new Repository();
var sutMock = new Mock<TestRepository>(repository) { CallBase = true };
var sut = sutMock.Object;
sut.GetByName("John Doe");
sutMock.Verify(x => x.GetByName("John Doe"), Times.Once);
NB: The fact that you'd need a legacy code testing technique probably indicates to a code smell. I would recommend, as a first step, splitting the tests that assert the mock from those that assert the real implementation results (changes in the persistence layer).
Related
We are transitioning from Xamarin.Forms to .Net MAUI but our project uses Prism.Unity.Forms. We have a lot of code that basically uses the IContainer.Resolve() passing in a collection of ParameterOverrides with some primitives but some are interfaces/objects. The T we are resolving is usually a registered View which may or may not be the correct way of doing this but it's what I'm working with and we are doing it in backend code (sometimes a service). What is the correct way of doing this Unity thing in DryIoC? Note these parameters are being set at runtime and may only be part of the parameters a constructor takes in (some may be from already registered dependencies).
Example of the scenario:
//Called from service into custom resolver method
var parameterOverrides = new[]
{
new ParameterOverride("productID", 8675309),
new ParameterOverride("objectWithData", IObjectWithData)
};
//Custom resolver method example
var resolverOverrides = new List<ResolverOverride>();
foreach(var parameterOverride in parameterOverrides)
{
resolverOverrides.Add(parameterOverride);
}
return _container.Resolve<T>(resolverOverrides.ToArray());
You've found out why you don't use the container outside of the resolution root. I recommend not trying to replicate this error with another container but rather fixing it - use handcoded factories:
internal class SomeFactory : IProductViewFactory
{
public SomeFactory( IService dependency )
{
_dependency = dependency ?? throw new ArgumentNullException( nameof(dependency) );
}
#region IProductViewFactory
public IProductView Create( int productID, IObjectWithData objectWithData ) => new SomeProduct( productID, objectWithData, _dependency );
#endregion
#region private
private readonly IService _dependency;
#endregion
}
See this, too:
For dependencies that are independent of the instance you're creating, inject them into the factory and store them until needed.
For dependencies that are independent of the context of creation but need to be recreated for each created instance, inject factories into the factory and store them.
For dependencies that are dependent on the context of creation, pass them into the Create method of the factory.
Also, be aware of potential subtle differences in container behaviours: Unity's ResolverOverride works for the whole call to resolve, i.e. they override parameters of dependencies, too, whatever happens to match by name. This could very well be handled very differently by DryIOC.
First, I would agree with the #haukinger answer to rethink how do you pass the runtime information into the services. The most transparent and simple way in my opinion is by passing it via parameters into the consuming methods.
Second, here is a complete example in DryIoc to solve it head-on + the live code to play with.
using System;
using DryIoc;
public class Program
{
record ParameterOverride(string Name, object Value);
record Product(int productID);
public static void Main()
{
// get container somehow,
// if you don't have an access to it directly then you may resolve it from your service provider
IContainer c = new Container();
c.Register<Product>();
var parameterOverrides = new[]
{
new ParameterOverride("productID", 8675309),
new ParameterOverride("objectWithData", "blah"),
};
var parameterRules = Parameters.Of;
foreach (var po in parameterOverrides)
{
parameterRules = parameterRules.Details((_, x) => x.Name.Equals(po.Name) ? ServiceDetails.Of(po.Value) : null);
}
c = c.With(rules => rules.With(parameters: parameterRules));
var s = c.Resolve<Product>();
Console.WriteLine(s.productID);
}
}
I want to write unit test for a class that contains linq to sql codes . I mean inside each method I have created a new DbContext and done database jobs .
I searched the web . first I came to use repository and Unit of Work patterns but I figured out that DbContext itself is a unit of work and its dbset works as repositories . another point is that I think there is no need to test Linq part because it works as it should ( tested by .net team ) . I want to test the logic I have added to the code . so I decided to create an interface with necessary methods with two implementations , one uses linqToSql while another is just a mock . something like this :
public interface IDbManager
{
bool Insert(MyEntity newEntity);
}
public class RealDbManager:IDbManager
{
public bool Insert(MyEntity newEntity)
{
using (DbDataContext db = new DbDataContext())
{
db.MyEntities.InsertOnSubmit(newEntity);
db.SubmitChanges();
}
}
}
public class MockDbManager:IDbManager
{
public bool Insert(MyEntity newEntity)
{
return true;
}
}
is the whole idea correct ? if so is this a correct implementation ?
is it possible to define DbDataContext as a class variable instead of creating new instance inside each method ?
You have the right general idea for a start. Your Mock Insert method should save the entity to some in-memory store so that subsequent queries will return the inserted information, as would be expected. But the very basic idea of having an interface, with a 'real' and a 'mock' implementation is there.
Remember that when using your Mock in tests, you are testing your other code that uses the mock - not the mock itself.
As for defining the DataContext as a member variable; you could use an IDisposable pattern for it, like so:
public class RealDbManager:IDbManager, IDisposable
{
DbDataContext db = new DbDataContext();
public bool Insert(MyEntity newEntity)
{
{
db.MyEntities.InsertOnSubmit(newEntity);
db.SubmitChanges();
}
}
public void Dispose()
{
db.Dispose();
}
}
You would just have to be sure to dispose of your DbManager, then.
Yes. The only thing I would avoid is to create an actual mocked class (in this case it should be called Fake), but using a mocking engine.
In your question you mention two kind of tests. First is testing the behavior of your class, the second is testing the integration of it. They seem the same but it's not.
In the first you need to mock your class to test its 'connection' against your other classes this way (using Moq):
[Test]
public void Test()
{
var entity = new Entity();
var mocked = new Mock<IDbManager>();
//you are telling the moq engine everytimes it finds an invocation of your repository
//to return true as you did in you mocked class
mocked.Setup( x => x.Insert( entity ) ).Returns( true );
var classUnderTest = new ClassUnderTest( mocked.Object );
//in this method you invoke your repository
var ret = classUnderTest.DoSomething( entity );
//assertions
Assert.Equal( something, ret);
//eventually you can verify that your repository has been hit once
mocked.Verify( x => x.Insert( It.IsAny<Entity>), Times.Once);
}
in the later as you correctly state, you have nothing to test on linq (Microsoft did it for us), but in case you need to verify the correctness of your linq you can do it only against a real db (or using a repository pattern against a fake repository). This is an integration test and it's has nothing to share with mocking.
To decouple your class from DbContext you could use repository pattern. Have a look at this article. http://dotnetspeak.com/index.php/2011/03/repository-pattern-with-entity-framework/
I'm building an ASP.NET MVC4 app. I'm not using any mocking framework and, if possible, would prefer not to at this point. My question is 2 parts.
I have a controller that uses a variable created in Global.asax. In the controller I access the variable like this.
HttpContext.Application["MyVar"]
1) Is this a best-practice for application wide variable usage? If not, what's the best way?
In an attempt to unit test this controller I added the following code (from here) to my test method.
MyController target = new MyController();
var request = new HttpRequest("", "http://example.com/", "");
var response = new HttpResponse(System.IO.TextWriter.Null);
var httpContext = new HttpContextWrapper(new HttpContext(request, response));
target.ControllerContext = new ControllerContext(httpContext, new RouteData(), target);
target.ControllerContext.HttpContext.Application["MyVar"] = new MyVar();
The problem is I can't add anything to Application. The last line of code doesn't seem to do anything and the collection remains empty. I've also tried this in VS's Immediate Window without success.
2) In the unit test, how can I add the application level variables the controller needs?
In general globals aren't good for testing. There are at least two approaches you could take.
Use a mocking framework like Pex/Moles, NMock, etc.
Use an inversion-of-control approach (NInject is my favorite). If class like a controller has an external dependency, it asks for the interface, typically in its constructor.
private readonly IApplicationSettings _settings;
public MyController(IApplicationSettings settings)
{
_settings = settings;
}
void someMethod()
{
_settings.Get("MyVar");
}
This way you can write real and test implementations.
public LiveAppSettings : IApplicationSettings
{
public string Get(string key)
{
return HttpContext.Current.Application[key];
}
}
With Ninject, you can bind either implementation at application startup:
var kernel = new StandardKernel();
kernel.Bind<IApplicationSettings>().To<LiveAppSettings>();
Is this a best-practice for application wide variable usage?
Best practice is a bit of a subjective notion and without fully explaining your scenario and what precisely are you trying to achieve I prefer not to discuss it.
We cannot discuss whether this is best practice but from what I can see it is not wrong either. It is not wrong because you are using the abstractions allowing the code to be unit tested.
In the unit test, how can I add the application level variables the controller needs?
You could use a mocking framework such as Rhino Mocks to mock the abstractions that the controller needs. Let's take as an example the following controller:
public class HomeController : Controller
{
public ActionResult Index()
{
var myVar = (MyVar)HttpContext.Application["MyVar"];
return Content(myVar.Foo);
}
}
and we would like to unit test the Index action. Here's a sample unit test:
[TestMethod]
public void Index_Action_Should_Retrieve_MyVal_From_AppState()
{
// arrange
var target = new HomeController();
var httpContext = MockRepository.GeneratePartialMock<HttpContextBase>();
var application = MockRepository.GeneratePartialMock<HttpApplicationStateBase>();
application.Expect(x => x["MyVar"]).Return(new MyVar { Foo = "bar" });
httpContext.Expect(x => x.Application).Return(application);
target.ControllerContext = new ControllerContext(httpContext, new RouteData(), target);
// act
var actual = target.Index() as ContentResult;
// assert
Assert.AreEqual("bar", actual.Content);
}
My app has a ProviderFactory static class that has static utility methods passing back static instances of things like a logger. The rest of my app then can just grab a/the reference to the logger from anywhere without having to pass in the logger (common design practice).
So, another part of my app, the DbCacheProvider, has methods that make calls to the logger so internally it gets a reference to the logger from the factory and then issues calls to it.
My question is that using Moq, I want to verify methods on the logger are being called by the methods within the DbCacheProvider. I can do this using dependency injection when I pass a mock logger into the DbCacheProvider as a parameter, but I'm not passing the logger in (not do I want to). So, how would I verify the DbCacheProvider is making calls to the logger?
If you don't want to pass the logger in through the constructor you'd need to change your ProviderFactory while running unit tests to return your mocked logger.
Anyway there are a couple of reasons it's often suggested to set up dependency injection:
Your tests are more straightforward and don't involve finagling with custom factories
IoC frameworks like Unity, Ninject and Autofac make it easy to create objects when their dependencies are set up this way. If you set up all of your objects this way, the framework will do all the heavy lifting of creating the right objects and passing them in for you. The dependency injection is done automatically and won't be a burden for you.
Old question without an answer, I had a similar problem and solved it like this:
I have the following sample code and need to verify that not only was a method called but was called with a specific value.
public interface ILog
{
void Info(string message);
}
public interface ILogFactory
{
ILog GetLogger();
}
This is the class being tested, where the interface items are being injected:
public class NewAction
{
readonly ILogFactory _logger;
public NewAction(ILogFactory logger)
{
_logger = logger;
}
public void Step1()
{
_logger.GetLogger().Info("Step 1");
}
public void Step2()
{
_logger.GetLogger().Info("Step 2");
}
}
This is obviously a very simplistic view of my actual code, but I needed to verify that Step1 and Step2 are behaving as expected and passed the correct values to the Log, this would mean I also needed to ensure they occurred in the right order. My test:
[TestClass]
public class UnitTest1
{
[TestMethod]
public void TestMethod1()
{
// Arrange
var log = new Mock<ILog>();
var factory = new Mock<ILogFactory>();
factory.Setup(l => l.GetLogger()).Returns(log.Object);
// Act
var action = new NewAction(factory.Object);
action.Step1();
action.Step2();
// Assert
factory.Verify(l => l.GetLogger());
log.Verify(l => l.Info(It.Is<string>(s => s == "Step 1")));
log.Verify(l => l.Info(It.Is<string>(s => s == "Step 2")));
}
}
Hope this helps.
I'm trying to work out how to complete my implementation of the Repository pattern in an ASP.NET web application.
At the moment, I have a repository interface per domain class defining methods for e.g. loading and saving instances of that class.
Each repository interface is implemented by a class which does the NHibernate stuff. Castle Windsor sorts out the DI of the class into the interface according to web.config. An example of an implemented class is provided below:
public class StoredWillRepository : IStoredWillRepository
{
public StoredWill Load(int id)
{
StoredWill storedWill;
using (ISession session = NHibernateSessionFactory.OpenSession())
{
storedWill = session.Load<StoredWill>(id);
NHibernateUtil.Initialize(storedWill);
}
return storedWill;
}
public void Save(StoredWill storedWill)
{
using (ISession session = NHibernateSessionFactory.OpenSession())
{
using (ITransaction transaction = session.BeginTransaction())
{
session.SaveOrUpdate(storedWill);
transaction.Commit();
}
}
}
}
As pointed out in a previous thread, the repository class needs to accept an unit of work container (i.e. ISession) rather than instantiating it in every method.
I anticipate that the unit of work container will be created by each aspx page when needed (for example, in a property).
How do I then specify that this unit of work container instance is to be passed into the constructor of StoredWillRepository when Windsor is creating it for me?
Or is this pattern completely wrong?
Thanks again for your advice.
David
I have a persistence framework built on top of NHibernate that is used in a few Web apps. It hides the NH implementation behind an IRepository and IRepository<T> interface, with the concrete instances provided by Unity (thus I could in theory swap out NHibernate for, say, Entity Framework fairly easily).
Since Unity doesn't (or at least the version I'm using doesn't) support the passing in of constructor parameters other than those that are dependency injections themselves, passing in an extant NH ISession isn't possible; but I do want all objects in the UOW to share the same ISession.
I solve this by having a controlling repository class that manages access to the ISession on a per-thread basis:
public static ISession Session
{
get
{
lock (_lockObject)
{
// if a cached session exists, we'll use it
if (PersistenceFrameworkContext.Current.Items.ContainsKey(SESSION_KEY))
{
return (ISession)PersistenceFrameworkContext.Current.Items[NHibernateRepository.SESSION_KEY];
}
else
{
// must create a new session - note we're not caching the new session here... that's the job of
// BeginUnitOfWork().
return _factory.OpenSession(new NHibernateInterceptor());
}
}
}
}
In this example, PersistenceFrameworkContext.Current.Items accesses an IList<object> that is stored either ThreadStatic if not in a Web context, or within HttpContext.Current.Items if it is in a Web context (to avoid thread-pool problems). The first call to the property instantiates the ISession from the stored factory instance, subsequent calls just retrieve it from storage. The locking will slow things down slightly but not as much as just locking an appdomain-scoped static ISession instance.
I then have BeginUnitOfWork and EndUnitOfWork methods to take care of the UOW - I have specifically disallowed nested UOWs because frankly they were a pain to manage.
public void BeginUnitOfWork()
{
lock (_lockObject)
{
if (PersistenceFrameworkContext.Current.Items.ContainsKey(SESSION_KEY))
EndUnitOfWork();
ISession session = Session;
PersistenceFrameworkContext.Current.Items.Add(SESSION_KEY, session);
}
}
public void EndUnitOfWork()
{
lock (_lockObject)
{
if (PersistenceFrameworkContext.Current.Items.ContainsKey(SESSION_KEY))
{
ISession session = (ISession)PersistenceFrameworkContext.Current.Items[SESSION_KEY];
PersistenceFrameworkContext.Current.Items.Remove(SESSION_KEY);
session.Flush();
session.Dispose();
}
}
}
Finally, a pair of methods provide access to the domain-type-specific repositories:
public IRepository<T> For<T>()
where T : PersistentObject<T>
{
return Container.Resolve<IRepository<T>>();
}
public TRepository For<T, TRepository>()
where T : PersistentObject<T>
where TRepository : IRepository<T>
{
return Container.Resolve<TRepository>();
}
(Here, PersistentObject<T> is a base class providing ID and Equals support.)
Access to a given repository is thus in the pattern
NHibernateRepository.For<MyDomainType>().Save();
This is then facaded over such that you can use
MyDomainType.Repository.Save();
Where a given type has a specialised repository (ie needs more than it can get from IRepository<T>) then I create an interface deriving from IRepository<T>, an extending implementation inheriting from my IRepository<T> implementation, and in the domain type itself I override the static Repository property using new
new public static IUserRepository Repository
{
get
{
return MyApplication.Repository.For<User, IUserRepository>();
}
}
(MyApplication [which is called something less noddy in the real product] is a facade class which takes care of supplying the Repository instance via Unity so you have no dependency on the specific NHibernate repository implementation within your domain classes.)
This gives me full pluggability via Unity for the repository implementation, easy access to the repository in code without jumping through hoops, and transparent, per-thread ISession management.
There's lots more code than just what's above (and I've simplified the example code a great deal), but you get the general idea.
MyApplication.Repository.BeginUnitOfWork();
User user = User.Repository.FindByEmail("wibble#wobble.com");
user.FirstName = "Joe"; // change something
user.LastName = "Bloggs";
// you *can* call User.Repository.Save(user), but you don't need to, because...
MyApplication.Repository.EndUnitOfWork();
// ...causes session flush which saves the changes automatically
In my Web app, I have session-per-request, so BeginUnitOfWork and EndUnitOfWork get called in BeginRequest and EndRequest respectively.
I have a pretty similar structure to yours, and here's how I solve your question:
1) To specify my container on each method, I have a separate class ("SessionManager") which I then invoke via a static property. By doing so, here's an example using my Save implementation:
private static ISession NHibernateSession
{
get { return SessionManager.Instance.GetSession(); }
}
public T Save(T entity)
{
using (var transaction = NHibernateSession.BeginTransaction())
{
ValidateEntityValues(entity);
NHibernateSession.Save(entity);
transaction.Commit();
}
return entity;
}
2) My container is not created on each ASPX page. I instantiate all of my NHibernate goodness on the global.asax page.
** A few more things spring up **
3) You don't need to have a helper to instantiate the Load. You might as well use Get instead of Load. More information # Difference between Load and Get.
4) Using your current code, you would have to repeat pretty much the same code for each domain object you need (StoredWillRepository, PersonRepository, CategoryRepository, etc..?), which seems like a drag. You could very well use a generic class to operate over NHibernate, like:
public class Dao<T> : IDao<T>
{
public T SaveOrUpdate(T entity)
{
using (var transaction = NHibernateSession.BeginTransaction())
{
NHibernateSession.SaveOrUpdate(entity);
transaction.Commit();
}
return entity;
}
}
In my implementation, I could then use something like:
Service<StoredWill>.Instance.SaveOrUpdate(will);
Technically, the answer to my question is to use the overload of container.Resolve which allows you to specify the constructor argument as an anonymous type:
IUnitOfWork unitOfWork = [Code to get unit of work];
_storedWillRepository = container.Resolve<IStoredWillRepository>(new { unitOfWork = unitOfWork });
But let's face it, the answers provided by everyone else have been much more informative.