How to write Xunit test case of factory design pattern code block which is tightly coupled? - oop

Question

I would like to write xunit test case of below method. Could you please suggest alternate design so i can write xunit test case with minimum change in my current project.
public ActionResult Index(int id = 0, AssetFilterType filter = AssetFilterType.All)
{
using (var tracer = new Tracer("AssetController", "Index"))
{
RemoveReturnUrl();
ViewBag.JobId = id;
var response = ContextFactory.Current.GetDomain<EmployeeDomain>().GetEmployeeFilterAsync(id,
CurrentUser.CompanyId, filter); // Not able write unit test case , please suggest alternate design.
return View("View", response);
}
}
current design is as follow
public interface IDomain
{
}
public interface IContext
{
D GetDomain<D>() where D : IDomain;
string ConnectionString { get; }
}
public class ApplicationContext : IContext
{
public D GetDomain<D>() where D : IDomain
{
return (D)Activator.CreateInstance(typeof(D));
}
public string ConnectionString
{
get
{
return "DatabaseConnection";
}
}
}
public class ContextFactory
{
private static IContext _context;
public static IContext Current
{
get
{
return _context;
}
}
public static void Register(IContext context)
{
_context = context;
}
}
//var response = ContextFactory.Current.GetDomain**< EmployeeDomain>**().GetEmployeeFilterAsync(id,
CompanyId, filter);
This line serve purpose to call specific class method i.e GetEmployeeFilterAsync from EmployeeDomain. Although it is very handy and widely used in our application but due to design issue i am not able to write unit
test case.
Could you please suggest design so with the minimum change we can write unit test case.

Answer 1

Don't use the Service Locator anti-pattern, use Constructor Injection instead. I can't tell what AssetDomain is from the OP, but it seems as though it's the dependency that matters. Inject it into the class:
public class ProbablySomeController
{
public ProbablySomeController(AssetDomain assetDomain)
{
AssetDomain = assetDomain;
}
public AssetDomain AssetDomain { get; }
public ActionResult Index(int id = 0, AssetFilterType filter = AssetFilterType.All)
{
using (var tracer = new Tracer("AssetController", "Index"))
{
RemoveReturnUrl();
ViewBag.JobId = id;
var response = AssetDomain.GetAssetFilterAsync(id, CurrentUser.CompanyId, filter);
return View("View", response);
}
}
}
Assuming that AssetDomain is a polymorphic type, you can now write a test and inject a Test Double:
[Fact]
public void MyTest()
{
var testDouble = new AssetDomainTestDouble();
var sut = new ProbablySomeController(testDouble);
var actual = sut.Index(42, AssetFilterType.All);
// Put assertions here
}

Answer 2

step1 : Required library
step 2 : When the application starts , register required domain like
protected void Application_Start()
UnityConfig.RegisterComponents();
Step 3: create one static class and register all your domain
example
public static class UnityConfig
{
public static void RegisterComponents()
{
var container = new UnityContainer();
Initialize domain which will injected in controller
container.RegisterType<IPricingDomain, PricingDomain>();
GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
}
}
step 4 :
so you can inject respective interface in constructor
in controller file.
goal : get rid of below any pattern in your project.
and start writing unit test cases.