We are migrating to Azure.Messaging.EventHubs.Processor v5.6.0 library from Microsoft.Azure.EventHubs.Processor v4.1.0. I m using await messageHandler.HandleEventAsync(args); where args is of ProcessEventArgs type. Most of our business logic that I want to unit test is based on EventData which is a property of ProcessEventArgs. Event data has Readonly dictionary of systemProperties and other properties. The public constructor of EventData does not let us specify the systemProperties or any other property other than EventData body.
Both ProcessEventArgs and EventBody do not have mockable interfaces. In such case can you please advise on how can we unit test the code using ProcessEventArgs?
.NET Version: .Net core app 3.1
NuGet package version : Azure.Messaging.EventHubs.Processor v5.6.0, Microsoft.NET.Test.Sdk v16.6.1
The recommended approach for testing your handlers is to call them directly, as you're attempting to do. The constructor for each of the event argument types is public. (example: ProcessEventArgs).
For the PartitionContext, broker-owned properties on EventData, and other model types without a public constructor, the EventHubsModelFactory allows you to create them for use in mocking/testing scenarios.
This article offers more information on the philosophy and approach the Azure SDK takes for supporting unit testing. For Event Hubs specifically, we're currently working on extending our samples to include a set of direct examples for core scenarios such as yours.
Related
I'm working on a dotnet core project, trying to mock some third party classes in my Xunit.net tests. The class I'm trying to fake is not mockable through constrained frameworks like Moq or NSubstitute. So I need an unconstrained framework to do that.
Say I want to fake DateTime.Now in my .net core test projects.
In .net 4.5 we have MSFakes(Moles), Smocks, etc. None of them support dotnet core framework yet. Shim is not ported to dotnet core yet.
Anyone knows any isolation framework or technique that will achieve my goal for .NET Core at the present time?
You could try a different way: wrap those third party libs with your own interfaces and wrapper classes. Then use a dummy object implementing that interface.
Things become more complicated with static properties like DateTime.Now. But it works similar: define an ITimeProvider interface with a Now property. Add a DateTimeWrapper : ITimeProvider with a public DateTime Now => DateTime.Now;, and - for convenience, but not required - a static class around it, e.g.
static class MyClock
{
static ITimeProvider _Instance;
static void SetInstanceForTesting(ITimeProvider instance)
{ _Instance = instance; }
static DateTime Now => _Instance.Now;
}
Alternatively, you may inject an ITimeProvider instance to the objects needing it.
A somewhat late reply, but for anyone else looking after the same kind of functionality I would recommend the open source git project prig: https://github.com/urasandesu/Prig It can fake static methods (they even have an example of faking and isolating DateTime.Now) and is an alternative to Microsoft Fakes, TypeMock and JustMock (all who cost money or require ultimate editions of visual studio to use).
Pose is an option. It's free full in memory
Https://GitHub.com/tonerdo/pose
I've researched some information about techniques I could use to unit test a DbContext. I would like to add some in-memory data to the context so that my tests could run against it. I'm using Database-First approach.
The two articles I've found most usefull were this and this.
That approach relies on creating an IContext interface that both MyContext and FakeContext will implement, allowing to Mock the context.
However, I'm trying to avoid using repositories to abstract EF, as pointed by some people, since EF 4.1 already implements repository and unit of work patterns through DbSet and DbContext, and I really would like to preserve all the features implemented by the EF Team without having to maintain them myself with a generic repository, as I already did in other project (and it was kind of painful).
Working with an IContext will lead me to the same path (or won't it?).
I thought about creating a FakeContext that inherits from main MyContext and thus take advantage of the DbContext underneath it to run my tests without hitting the database.
I couldn't find similar implementations, so I'm hoping someone can help me on this.
Am I doing something wrong, or could this lead me to some problems that I'm not anticipating?
Ask yourself a single question: What are you going to test?
You mentioned FakeContext and Mocking the context - why to use both? Those are just different ways to do the same - provide test only implementation of the context.
There is one more bigger problem - faking or mocking context or set has only one result: You are not testing your real code any more.
Simple example:
public interface IContext : IDisposable
{
IDbSet<MyEntity> MyEntities { get; }
}
public class MyEntity
{
public int Id { get; set; }
public string Path { get; set; }
}
public class MyService
{
private bool MyVerySpecialNetMethod(e)
{
return File.Exists(e.Path);
}
public IEnumerable<MyEntity> GetMyEntities()
{
using (IContext context = CreateContext())
{
return context.MyEntities
.Where(e => MyVerySpecialNetMethod(e))
.Select(e)
.ToList();
}
}
}
Now imagine that you have this in your SUT (system under test - in case of unit test it is an unit = usually a method). In the test code you provide FakeContext and FakeSet and it will work - you will have a green test. Now in the production code you will provide a another derived DbContext and DbSet and you will get exception at runtime.
Why? Because by using FakeContext you have also changed LINQ provider and instead of LINQ to Entities you are running LINQ to Objects so calling local .NET methods which cannot be converted to SQL works as well as many other LINQ features which are not available in LINQ to Entities! There are other issues you can find with data modification as well - referential integrity, cascade deletes, etc. That is the reason why I believe that code dealing with context / LINQ to Entities should be covered with integration tests and executed against the real database.
I am developing an open-source library to solve this problem.
http://effort.codeplex.com
A little teaser:
You don't have to add any boilerplate code, just simply call the appropriate API of the library, for example:
var context = Effort.ObjectContextFactory.CreateTransient<MyContext>();
At first this might seem to be magic, but the created ObjectContext object will communicate with an in-memory database and will not talk to the original real database at all. The term "transient" refers to the lifecycle of this database, it only lives during the presence of the created ObjectContext object. Concurrently created ObjectContext objects communicate with dedicated database instances, the data is not shared accross them. This enables to write automated tests easily.
The library provides various features to customize the creation: share data across instances, set initial data of the database, create fake database on different data layers... check out the project site for more info.
As of EF 4.3, you can unit test your code by injecting a fake DefaultConnectionFactory before creating the context.
Entity Framework 4.1 is close to being able to be mocked up in tests but requires a little extra effort. The T4 template provides you with a DbContext derived class that contains DbSet properties. The two things that I think you need to mock are the DbSet objects that these properties return and properites and methods you're using on the DbContext derived class. Both can be achieved by modifying the T4 template.
Brent McKendrick has shown the types of modifications that need to be made in this post, but not the T4 template modifications that can achieve this. Roughly, these are:
Convert the DbSet properties on the DbContext derived class into IDbSet properties.
Add a section that generates an interface for the DbContext derived class containing the IDbSet properties and any other methods (such as SaveChanges) that you'll need to mock.
Implement the new interface in the DbContext derived class.
Short version of my questions:
Can anyone point me toward some good, detailed sources from which I
can learn how to implement testing in my MVC 3 application, using
NUnit, Ninject 2, and Moq?
Can anyone here help clarify for me how Controller-Repository
decoupling, mocking, and dependency injection work together?
Longer version of my questions:
What I'm trying to do ...
I am currently beginning to create an MVC 3 application, which will use Entity Framework 4, with a database first approach. I want to do this right, so I am trying to design the classes, layers, etc., to be highly testable. But, I have little to no experience with unit testing or integration testing, other than an academic understanding of them.
After lots of research, I've settle on using
NUnit as my testing framework
Ninject 2 as my dependency injection framework
Moq as my mocking framework.
I know the topic of which framework is best, etc., could enter into this, but at this point I really don't know enough about any of it to form a solid opinion. So, I just decided to go with these free solutions which seem to be well liked and well maintained.
What I've learned so far ...
I've spent some time working through some of this stuff, reading resources such as:
Implementing the Repository and Unit of Work Patterns in an
ASP.NET MVC Application
Building Testable ASP.NET MVC Applications
NerdDinner Step 12: Unit Testing
Using Repository and Unit of Work patterns with Entity Framework
4.0
From these resources, I've managed to workout the need for a Repository pattern, complete with repository interfaces, in order to decouple my controllers and my data access logic. I have written some of that into my application already, but I admit I am not clear as to the mechanics of the whole thing, and whether I am doing this decoupling in support of mocking, or dependency injection, or both. As such, I certainly wouldn't mind hearing from you guys about this too. Any clarity I can gain on this stuff will help me at this point.
Where things got muddy for me ...
I thought I was grasping this stuff pretty well until I started trying to wrap my head around Ninject, as described in Building Testable ASP.NET MVC Applications, cited above. Specifically, I got completely lost around the point in which the author begins describing the implementation of a Service layer, about half way into the document.
Anyway, I am now looking for more resources to study, in order to try to get various perspectives around this stuff until it begins to make sense to me.
Summarizing all of this, boiling it down to specific questions, I am wondering the following:
Can anyone point me toward some good, detailed sources from which I
can learn how to implement testing in my MVC 3 application, using
NUnit, Ninject 2, and Moq?
Can anyone here help clarify for me how Controller-Repository
decoupling, mocking, and dependency injection work together?
EDIT:
I just discovered the Ninject official wiki on Github, so I'm going to start working through that to see if it starts clarifying things for me. But, I'm still very interested in the SO community thoughts on all of this :)
If you are using the Ninject.MVC3 nuget package, then some of the article you linked that was causing confusion will not be required. That package has everything you need to start injecting your controllers which is probably the biggest pain point.
Upon installing that package, it will create a NinjectMVC3.cs file in the App_Start folder, inside that class is a RegisterServices method. This is where you should create the bindings between your interfaces and your implementations
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<IRepository>().To<MyRepositoryImpl>();
kernel.Bind<IWebData>().To<MyWebDAtaImpl>();
}
Now in your controller you can use constructor injection.
public class HomeController : Controller {
private readonly IRepository _Repo;
private readonly IWebData _WebData;
public HomeController(IRepository repo, IWebData webData) {
_Repo = repo;
_WebData = webData;
}
}
If you are after very high test coverage, then basically anytime one logical piece of code (say controller) needs to talk to another (say database) you should create an interface and implementation, add the definition binding to RegisterService and add a new constructor argument.
This applies not only to Controller, but any class, so in the example above if your repository implementation needed an instance of WebData for something, you would add the readonly field and the constructor to your repository implementation.
Then when it comes to testing, what you want to do is provide mocked version of all required interfaces, so that the only thing you are testing is the code in the method you are writing the test for. So in my example, say that IRepository has a
bool TryCreateUser(string username);
Which is called by a controller method
public ActionResult CreateUser(string username) {
if (_Repo.TryCreateUser(username))
return RedirectToAction("CreatedUser");
else
return RedirectToAction("Error");
}
What you are really trying to test here is that if statement and the return types, you do not want to have to create a real repository that will return true or false based on special values you give it. This is where you want to mock.
public void TestCreateUserSucceeds() {
var repo = new Mock<IRepository>();
repo.Setup(d=> d.TryCreateUser(It.IsAny<string>())).Returns(true);
var controller = new HomeController(repo);
var result = controller.CreateUser("test");
Assert.IsNotNull(result);
Assert.IsOfType<RedirectToActionResult>(result)
Assert.AreEqual("CreatedUser", ((RedirectToActionResult)result).RouteData["Action"]);
}
^ That won't compile for you as I know xUnit better, and do not remember the property names on RedirectToActionResult from the top of my head.
So to sum up, if you want one piece of code to talk to another, whack an interface in between. This then allows you to mock the second piece of code so that when you test the first you can control the output and be sure you are testing only the code in question.
I think it was this point that really made the penny drop for me with all this, you do this not necessarily becase the code demands it, but because the testing demands it.
One last piece of advice specific to MVC, any time you need to access the basic web objects, HttpContext, HttpRequest etc, wrap all these behind an interface as well (like the IWebData in my example) because while you can mock these using the *Base classes, it becomes painful very quickly as they have a lot of internal dependencies you also need to mock.
Also with Moq, set the MockBehaviour to Strict when creating mocks and it will tell you if anything is being called that you have not provided a mock for.
Here is the application that I'm creating. It is open source and available on github, and utilizes all of the required stuff - MVC3, NUnit, Moq, Ninject - https://github.com/alexanderbeletsky/trackyt.net/tree/master/src
Contoller-Repository decoupling is simple. All data operations are moved toward the Repository. Repository is an implementation of some IRepository type. The controller never creates repositories inside itself (with the new operator) but rather receives them either by constructor argument or property.
.
public class HomeController {
public HomeController (IUserRepository users) {
}
}
This technique is called "Inversion of Control." To support inversion of control you have to provide some "Dependency Injection" framework. Ninject is a good one. Inside Ninject you associate some particular interface with an implementation class:
Bind<IUserRepository>().To<UserRepository>();
You also substitute the default controller factory with your custom one. Inside the custom one you delegate the call to the Ninject kernel:
public class TrackyControllerFactory : DefaultControllerFactory
{
private IKernel _kernel = new StandardKernel(new TrackyServices());
protected override IController GetControllerInstance(
System.Web.Routing.RequestContext requestContext,
Type controllerType)
{
if (controllerType == null)
{
return null;
}
return _kernel.Get(controllerType) as IController;
}
}
When the MVC infrastructure is about to create a new controller, the call is delegated to the custom controller factory GetControllerInstance method, which delegates it to Ninject. Ninject sees that to create that controller the constructor has one argument of type IUserRepository. By using the declared binding, it sees that "I need to create a UserRepository to satisfy the IUserRepository need." It creates the instance and passes it to the constructor.
The constructor is never aware of what exact instance would be passed inside. It all depends on the binding you provide for that.
Code examples:
https://github.com/alexanderbeletsky/trackyt.net/blob/master/src/Web/Infrastructure/TrackyServices.cs https://github.com/alexanderbeletsky/trackyt.net/blob/master/src/Web/Infrastructure/TrackyControllerFactory.cs https://github.com/alexanderbeletsky/trackyt.net/blob/master/src/Web/Controllers/LoginController.cs
Check it out : DDD Melbourne video - New development workflow
The whole ASP.NET MVC 3 development process was very well presented.
The third party tools I like most are:
Using NuGet to install Ninject to enable DI throughout the MVC3
framework
Using NuGet to install nSubstite to create mocks to enable unit
testing
I'm working on a web application that is built over Sitecore CMS. I was wondering if we could unit test for example a method that takes some data from Sitecore makes some processing with it and spits out a result. I would like to test all the logic within the method via a unit test.
I pretty confused after searching the internet wide and deep. Some say that this kind of testing is actually integration testing and not unit testing and I should test only the code that has no Sitecore calls, others say that this is not possible because the Sitecore context would be missing.
I would like to ask for your help experienced fellow programmers:
Can I unit test a method that contains Sitecore calls ? If YES, how ? If NO, why ? Is there any workaround ?
The project is at its beginning, so there will be no problem in choosing between unit testing frameworks such as MSTest or Nunit, if it is the case that the solution is related to the unit testing framework of choice.
It's pretty hard to find out anything about Sitecore without providing email and living through the sales pitch, so I'll just provide a generic approach on how to do something like this.
First and foremost, you assume that the Sitecore API is guaranteed to work - i.e. it's a framework - and you don't unit test it. You should be unit testing your interactions with it.
Then, download MOQ and read the quick start on how to use it. This is my preferred mocking framework. Feel free to use other frameworks if you wish.
Hopefully, Sitecore API provides a way for you to create data objects without dealing with persistence - i.e. to simply create a new instance of whatever it is you are interested in. Here is my imaginary API:
public class Post {
public string Body {get;set;}
public DateTime LastModified {get;set;}
public string Title {get;set;}
}
public interface ISiteCorePosts {
public IEnumerable<Post> GetPostsByUser(int userId);
}
In this case unit testing should be fairly easy. With a bit of Dependency Injection, you can inject the SiteCore interfaces into your component and then unit test it.
public class MyPostProcessor {
private readonly ISiteCorePosts m_postRepository;
public MyPostProcessor(ISiteCorePosts postRepository) {
m_postRepository = postRepository;
}
public void ProcessPosts(int userId) {
var posts = m_postRepository.GetPostsByUser(userId);
//do something with posts
}
}
public class MyPostProcessorTest {
[TestMethod]
ProcessPostsShouldCallGetPostsByUser() {
var siteCorePostsMock = new Mock<ISiteCorePosts>();
//Sets up the mock to return a list of posts when called with userId = 5
siteCorePostsMock.Setup(m=>m.GetPostsByUser(5)).Returns(new List<Post>{/*fake posts*/});
MyPostProcessor target = new MyPostProcessor(siteCorePostsMock.Object);
target.ProcessPosts(5);
//Verifies that all setups are called
siteCorePostsMock.VerifyAll();
}
}
If ISiteCorePosts is not, in fact, an interface and is a concrete class whose methods are not virtual and thus cannot be mocked, you will need to use Facade pattern to wrap the SiteCore interaction to make it more testing friendly.
public class SiteCorePostsFacade {
SiteCorePosts m_Posts = new SiteCorePosts();
//important - make this method virtual so it can be mocked without needing an interface
public virtual IEnumerable<Post> GetPostsByUser(int userId) {
return m_Posts.GetPostsByUser(userId);
}
}
You then proceed to use SiteCorePostsFacade as though it was an interface in the previous example. Good thing about MOQ is that it allows you to mock concrete classes with virtual methods, not just interfaces.
With this approach, you should be able to inject all sorts of data into your application to test all interactions with SiteCore API.
we have used a custom WebControl placed on a WebForm for our integration tests some years now, which wraps the NUnit Test Suite runner functionality much like the NUnit GUI. It show a pretty grid of executed tests with links to fixtures and categories to execute specific tests. Its created much like described here http://adeneys.wordpress.com/2010/04/13/new-technique-for-unit-testing-renderings-in-sitecore/ (the custom test runner part). Our implementation can also return raw NUnit xml for further processing by for example a build server.
I've tried MSTest a while back and it also works when specified that it should launch a WebDev / IIS site to test. It works but is extremely slow compared to above solution.
Happy testing!
Short answer:
You need to mock calls to SiteCore CMS.
Long answer:
I am not aware about SiteCore CMS. But, from your question looks like it is something that is external to your application. Components external to your system should always be used via interface. This has two benefits:
If you want to use another CMS system, you can easily do as your application is just talking to an interface.
It helps you with behavior testing by mocking the interface.
The code you write is your responsibility and hence you should only unit test that piece of code. Your unit tests should ensure that your code calls appropriate SiteCode CMS methods in various scenarios (behavior tests). You can do this using mocking. I use moq for mocking.
As tugga said, it depends upon how tightly the code you want to test is coupled to SiteCore. If it's something like:
SomeSiteCoreService siteCoreDependency = new SomeSiteCoreService()
Then this would be very difficult to test. If SiteCore provides you an interface, then you have more flexibility to unit test it. You could pass the implementation into your method either (contstructor, class property, or method parameter) and then you can send in a fake implementation of that service.
If they do not provide you with an interface, then you have to do a little more work. You would write an adapter interface of your own and the default implementation would delegate to the 3rd party dependency.
public interface ICMSAdapter{
void DoSomethingWithCMS()
}
public class SiteCoreCMSAdapter: ICMSAdapter{
SiteCoreService _cms = new SiteCoreService();
public void DoSomethingWithCMS(){
_cms.DoSomething();
}
That keeps your 3rd party dependencies at arms length and provides seams to all sorts of cool things, like unit tests and you do interception style architecture and do your own thing before and after the call.
}
I was able to get unit tests to interact with sitecore api in VS 2015. The same test throws a StackOverflow exception when run in VS 2012.
For example, this method call runs fine in VS2015 but not VS2015:
Context.SetActiveSite("mysite");
quick note: this assumes you have a site named mysite setup in your config file
I've not seen anything in this area I would recommend to a client. If you've used Spring PortletMVC, how did you test it?
It's easy to test under the level of portlet code, and relatively easy to test on the client side through HtmlUnit, Selenium and the like, but I haven't seen anything that is a "Gray Box" test in the spirit of JSFUnit (which looks to me to be the way forward).
Apache's Pluto driver could theoretically be used to bootstrap a test harness. Has anyone tried this?
Any stub or data provider approaches?
Any approach to address two-phase processing concerns?
I don't know anything about portlets but here it goes.
There's portletUnit.
portletUnit is a testing framework
used to test JSR-168 portlets outside
portlet container just as servletUnit
is used to test servlets outside a
servlet container. The projected is
architected to map the functionally of
servletUnit onto portlets with
servletUnit itself providing the
foundation for portletUnit.
Some more related info could be found on his Project PortletUnit blog, including PortletUnit and Spring Portlet: Checking form validation errors.
When testing with portletUnit, it is
not obvious how to check if there were
any form errors. Fortunately, using
the render listener feature of
PortletRunner, there is a simple way
to check for validator errors.
There's also a blog article written by Nils-Helge Garli Hegvik in 2007 titled Testing Portlets with Jetty, Pluto and JWebUnit.
Remembering an excellent article from
Johannes Brodwall's blog about
integration testing with Jetty and
JWebUnit, I wanted to extend his
approach to use the embedded
jetty-pluto setup I have created. This
turned out to be to be quite easy.
Finally, Spring Framework documentation 10.2 Unit testing.
The
org.springframework.mock.web.portlet
package contains a set of Portlet API
mock objects, targeted at usage with
Spring's Portlet MVC framework.
[...] The org.springframework.test.web
package contains ModelAndViewAssert,
which can be used in combination with
any testing framework (e.g., JUnit 4+,
TestNG, etc.) for unit tests dealing
with Spring MVC ModelAndView objects.
[...] To test your Spring MVC Controllers, use
ModelAndViewAssert combined with
MockHttpServletRequest,
MockHttpSession, etc. from the
org.springframework.mock.web package.
Here's a related article written by John Ferguson Smart titled
Unit testing your Spring-MVC applications.
One of the great things about this
framework is how testable it is. In
Spring-MVC, any custom validators (for
field and form validation) and
property editors (for converting text
fields to specific Java types) are
dead-easy to test - you can just test
them as if they where isolated POJOs.
Spring-MVC also comes with a full set
of mock objects that you can use (with
a bit of practice) to test your
controllers to your heart's content.
For example, you can use classes like
MockHttpServletRequest and
MockHttpServletResponse to simulate
your HTTP request and response
objects. This is also made easier by
the fact that Controllers can be
instanciated as normal Java classes.
For example, imagine you are testing a
controller class for a page that
updates a client details record. You
could do this very simply as follows:
public class UpdateClientTest {
//
// Prepare your request
//
request.setMethod("POST");
request.setParameter("id", "100");
request.setParameter("firstName", "Jane");
request.setParameter("lastName", "Doe");
//
// Invoke the controller
//
controller = new ChoosePeriodController();
ModelAndView mav = controller.handleRequest(request, response);
//
// Inject any service objects you need
//
controller.setClientService(clientService);
...
//
// Inspect the results
//
assert mav != null;
assertEquals("displayClient",mav.getViewName());
Client client = (Client) mav.getModel().get("client");
assertEquals("Jane",client.getFirstName());
assertEquals("Doe",client.getLastName());
...
}
...
Checkout spring-test-portlet-mvc (https://github.com/markusf/spring-test-portlet-mvc), which exposes the features of MockMvc to the Portal context and lets you integration test your Spring Portlets easily.