Create a gist now

Instantly share code, notes, and snippets.

What would you like to do?
Playing with LightInject Constructor Injection
using LightInject;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace UnitTestProject1
{
[TestClass]
public class UnitTest1
{
public interface IMyService
{
string CalledConstructor { get; }
}
public class MyService : IMyService
{
public MyService()
{
CalledConstructor = "MyService()";
}
public MyService(string parameterOne)
{
CalledConstructor = string.Format("MyService(parameterOne: {0}", parameterOne);
}
public MyService(string parameterOne, string parameterTwo)
{
CalledConstructor = string.Format("MyService(parameterOne: {0}, parameterTwo: {1}", parameterOne, parameterTwo);
}
public string CalledConstructor { get; private set; }
}
public class MyInheritedService : MyService
{
public MyInheritedService(string parameterOne) : base(parameterOne) { }
}
[TestMethod]
public void Resolve_should_use_default_constructor()
{
var container = new ServiceContainer();
container.Register<IMyService, MyService>();
var service = container.GetInstance<IMyService>();
Assert.AreEqual("MyService()", service.CalledConstructor);
}
[TestMethod]
public void FAILS_Resolve_should_use_constructor_with_one_parameter_but_chooses_the_one_with_two()
{
var container = new ServiceContainer();
container.RegisterInstance("FirstValue", "parameterOne");
container.Register<IMyService, MyService>();
var service = container.GetInstance<IMyService>();
Assert.AreEqual(
string.Format("MyService(parameterOne: {0}", "FirstValue"),
service.CalledConstructor);
}
[TestMethod]
public void Resolve_should_use_constructor_with_two_parameter2()
{
var container = new ServiceContainer();
container.RegisterInstance("FirstValue", "parameterOne");
container.RegisterInstance("SecondValue", "parameterTwo");
container.Register<IMyService, MyService>();
var service = container.GetInstance<IMyService>();
Assert.AreEqual(
string.Format("MyService(parameterOne: {0}, parameterTwo: {1}", "FirstValue", "SecondValue"),
service.CalledConstructor);
}
[TestMethod]
public void Solution_1_hide_constructor()
{
var container = new ServiceContainer();
container.RegisterInstance("FirstValue", "parameterOne");
container.Register<IMyService, MyInheritedService>();
var service = container.GetInstance<IMyService>();
Assert.AreEqual(
string.Format("MyService(parameterOne: {0}", "FirstValue"),
service.CalledConstructor);
}
[TestMethod]
public void Solution_2_prevent_resolveing_of_default_service()
{
var container = new ServiceContainer();
container.RegisterInstance("FirstValue", "parameterOne");
container.RegisterInstance("dummy", "dummy");
container.Register<IMyService, MyInheritedService>();
var service = container.GetInstance<IMyService>();
Assert.AreEqual(
string.Format("MyService(parameterOne: {0}", "FirstValue"),
service.CalledConstructor);
}
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment