I have a web application that has been created using MVC 3 and Entity Framework. I would like to start using unit testing, but so far I have not been able to run any unit tests due to the way the system talks to the database.
I have a BaseController, which defines a DataContext as a variable:
public class BaseController : Controller
{
public Models.MyEntities DataContext = new Models.MyEntities();
Each controller then inherits the BaseController, thereby making the DataContext variable available to all controllers without redefining it:
public class ErrorController : BaseController
{
When I run a unit test, I receive an error about the object reference not being set to an instance of an object, each time referring to the line where I access DataContext.
Most references to unit testing say you should be abstracting your database layer, and using fake data for testing. This seems counter-intuitive to me, but that is a different discussion.
My question is - is it possible to use unit testing with the system configured the way it is? I am open to using any testing framework available, either MSTest, NUnit / XUnit etc.
Related
Where I'm working one of our customer required to use a custom test framework written using testng that allows to handle different parameters and test iterations using excel files.
This framework uses a main class to handle all the tests, lets call it TestManager.
This TestManager defines all the #Before and #After operations and has a method called exec() which is annotated as #Test.
This method is used to call the different components required from the test, these components are java classes that implements a single method exec() containing the logic of the single component.
public class TestManager {
// ... Before, After methods
#Test(
dataProvider = "..."
)
public void exec(Parameter[] inParameter) {
// load parameters...
foreach component:
component.exec()
}
}
public class ComponentXYZ {
public void exec() {
// load input params
// Call a microservice and get results, find value on db, selenium operations...
// unload output params for next components
}
}
This framework was designed to be used with selenium, or to test microservices using some http request library and is contained in a standalone module.
So my project has:
A spring boot module
A test module which (in my idea) should have a dependency over the spring boot module
Given this situation do you think it could be possible to use WebMvcTest to perform integration tests while using this custom framework?
I've been trying for a while but I'm always getting errors or I'm not able to #Autowire MockMvc, I can't seem to start a minimal spring boot instance directly from this test framework...
I don't think running my spring boot app and calling the microservices using http is the correct way to test but at this moment is the only thing it's working.
So I'm trying to get my head around this for a while now, but I don't seem to succeed. In my application I'm using a generic repository with Entity Framework Core.
Hence my Repository always expect that it's accessed from a class who's BaseEntity or has inherited from that certain class.
Now I want to implement .Net Core Identity with it. But My User class is inheriting from BaseEntity. But I'd also need it to inherit from Identity in order to make it work I guess. How am I able to still use Identity?
C# only supports single inheritance. You cannot inherit from two different classes. Additionally your Identity user class, must inherit from IdentityUser. You have no choice in that. As a result, the best you can do is make your user class and the rest of your entity classes implement the same interface, i.e. IEntity. Then, instead of constraining your generic type as BaseEntity, use IEntity instead.
Of course, this means you will incur a bit of code duplication as you'll have to implement IEntity separately on both BaseEntity and your user class. However, that is unavoidable.
I'm trying to implement integration testing in my app and have test class like that:
#ExtendWith(value={MyDockerExtension.class})
#ExtendWith(value={SpringExtension.class})
#WebAppConfiguration
#ContextConfiguration(classes={...})
#TestInstance(TestInstance.LifeCycle.PER_CLASS)
public class TestClass{ ... }
Is there any way to make MyDockerExtension execute some code, before whole SpringExtension start working and generate whole Context with Configurationc classes?
I've heard that order in which we declare extensions is the key, but sadly MyDockerExtension that implements BeforeAllCallback, AfterAllCallback executes right before test method and after whole context is loaded. In that situation it's to late to start containers with docker, becuase since whole context is loaded my app already tried to connect to the container.
At first I was skeptical about the order being fixed but you're correct:
Extensions registered declaratively via #ExtendWith will be executed in the order in which they are declared in the source code.
Regarding the MyDockerExtension, you may want to look at the extension point TestInstancePostProcessor, which is called before #BeforeAll. SpringExtension implements it and I guess it's there where it sets up the application context. If you also implement it, you should be able to act before it does.
Can we unit test the action which are having access specifier as private? If possible how can we unit test the private actions?
You can but why do you have private action methods? I'd rethink that architecture a little bit more. If you forget to make it private it becomes URL addressable.
However if you really want to do this right click on the method and add a unit test. The unit test project will add an item to the apps assemblyinfo.cs [InternalsVisibleTo] so it's private methods can be accessed via a proxy that's created in the test project.
It's a bit messy may as well pull that out into a separate class and make it public or internal etc
One option is make the action public and decorate it with NonActionAttribute.
I am a newbie to MEF and I am really mixed up! There are lot of useful articles out there and neat question and answers here in stackoverflow. I downloaded the example which #matthew-abbott has uploaded in his blog , but I dont know how to add new plug-ins or extension to extend the main web application, I mean like what you can see here.
Edited :
Also I use Entity Framework, Code First Approach and Unit of work for my data access layer application, what If my plug-ins needs data access and (I mean the plug-in has itself models) wants to use the DAL I created ? As you know every time the model changes, DbContext throws and error and tells re-create DB, Is there any way or other ORM which accepts extending DAL dynamically?
That particular example shows how we can integrate MEF with MVC3's new DependencyResolver which provides a service location mechanism for various extension points within the MVC architecture. There are a few other articles on my blog which detail more information about how a possible plugin architecture could work, these are available at:
Modular ASP.NET MVC using the Managed Extensibility Framework (MEF), Part One
Modular ASP.NET MVC using the Managed Extensibility Framework (MEF), Part Two
Modular ASP.NET MVC using the Managed Extensibility Framework (MEF), Part Three
There are also a host of fantastic articles, my recommendations would be to also read:
ASP.NET MVC and the Managed Extensibility Framework (MEF) by Maarten Balliauw
Defining Web-scoped parts with MEF by Tim Roberts
MVC is a very flexible architecture, there are a myriad of ways it can be extended, but because of the nature of how ASP.NET applications run in IIS, you need to consider part lifetime very carefully. As an example, controllers can only be used for one request, so you could would need to ensure that your controllers have a specific CreationPolicy. Tim Robert's article on Web-scoped parts is a particularly good read.
Hope that is enough to point you in the right direction.
Edit: Because of the modular nature that MEF provides, it is important to ensure that your different layers are decoupled. You've specified that you are using Entity Framework, but the reality is, EF should likely only be used in your data layer. Typically the MVC architecture would promote view models over domain models. To that end, it is probably useful to use something similar to the repository pattern to define, e.g. here is a mock UserRepository:
[Export(typeof(IUserRepository))]
public class UserRepository : IUserRepository
{
public IEnumerable<UserViewModel> GetUsers()
{
// Get values here from EF as domain models
// And return them as view models?
}
}
Which we can export and inject into a controller:
[ExportController("User"), PartCreationPolicy(CreationPolicy.NonShared)]
public class UserController : Controller
{
private readonly IUserRepository _repo;
[ImportingConstructor]
public UserController(IUserRepository repo)
{
if (repo == null)
throw new ArgumentNullException("repo");
_repo = repo;
}
public ActionResult Index()
{
var users = _repo.GetUsers();
return View(users);
}
}
This is just a really simple example, but like many IoC containers, MEF also supports dependency injection. As long as a part provides a suitable export, it can be imported (either through property injection, or constructor injection) into another part at composition time.
My recommendation would be against exposing EF to your views, as this makes them explicitly dependent on it. By taking care to decouple and only expose the right types at the right layers, you architecture will become a lot more robust, flexible and testable, which makes maintaining it, and updating it a lot easier. As another quick example, here is how we could test our controller:
[Test]
public void UserController_CreatesViewResult_WithListOfUsers()
{
var mock = new Mock<IUserRepository>();
mock.Setup(m => m.GetUsers()).Returns(new[] { new UserViewModel { Name = "Matt" } });
var controller = new UserController(mock.Object);
var result = controller.Index();
Assert.That(result is ViewResult);
// Other assertions.
}
Because I haven't tightly coupled EF to my view, my controller is a lot more testable, I can mock a suitable repository and test where I need to.
The important thing is planning your architecture.