Nitrox/Nitrox.Test/Model/Core/DependencyInjectionTests.cs

using Autofac;

namespace NitroxModel.Core;

[TestClass]
public class DependencyInjectionTests
{
    [TestInitialize]
    public void Init()
    {
        NitroxServiceLocator.InitializeDependencyContainer(new DependencyInjectionTestsAutoFacRegistrar());
        NitroxServiceLocator.BeginNewLifetimeScope();
    }

    [TestMethod]
    public void ShouldResolveDependencyPolymorphically()
    {
        // Arrange
        IRootDependency polymorphicallyResolvedDependency = NitroxServiceLocator.LocateService<IRootDependency>();

        // Assert
        polymorphicallyResolvedDependency.Should().NotBeNull();
        polymorphicallyResolvedDependency.Should().BeOfType<RootDependency>();
    }

    [TestMethod]
    public void ShouldResolveConcreteType()
    {
        // Arrange
        DependencyWithRootDependency directConcreteTypeDependency = NitroxServiceLocator.LocateService<DependencyWithRootDependency>();

        // Assert
        directConcreteTypeDependency.Should().NotBeNull();
        directConcreteTypeDependency.RootDependency.Should().NotBeNull();
        directConcreteTypeDependency.RootDependency.Should().BeOfType<RootDependency>();
    }

    [TestMethod]
    public void ShouldResolveGenericDependencies()
    {
        // Arrange
        IServicer<ServiceRecipientA> servicerA = NitroxServiceLocator.LocateService<IServicer<ServiceRecipientA>>();
        IServicer<ServiceRecipientB> servicerB = NitroxServiceLocator.LocateService<IServicer<ServiceRecipientB>>();

        // Assert
        servicerA.Should().NotBeNull();
        servicerA.Should().BeOfType<ServiceAProvider>();
        Invoking(() => servicerA.PerformService(null)).Should().Throw<NotImplementedException>();

        servicerB.Should().NotBeNull();
        servicerB.Should().BeOfType<ServiceBProvider>();
        Invoking(() => servicerB.PerformService(null)).Should().Throw<NotImplementedException>();
    }

    [TestMethod]
    public void ShouldResolveGenericDependenciesFromManuallyConstructedTypeInstances()
    {
        // Arrange
        Type servicerInstanceType = typeof(IServicer<>);
        Type recipientAType = typeof(ServiceRecipientA);
        Type recipientBType = typeof(ServiceRecipientB);
        Type servicerAType = servicerInstanceType.MakeGenericType(recipientAType);
        Type servicerBType = servicerInstanceType.MakeGenericType(recipientBType);

        // Act
        IServicer<ServiceRecipientA> servicerA = (BaseServiceProvider<ServiceRecipientA>)NitroxServiceLocator.LocateService(servicerAType);
        IServicer<ServiceRecipientB> servicerB = (BaseServiceProvider<ServiceRecipientB>)NitroxServiceLocator.LocateService(servicerBType);

        // Assert
        servicerA.Should().NotBeNull();
        servicerA.Should().BeOfType<ServiceAProvider>();
        Invoking(() => servicerA.PerformService(null)).Should().Throw<NotImplementedException>();

        servicerB.Should().NotBeNull();
        servicerB.Should().BeOfType<ServiceBProvider>();
        Invoking(() => servicerB.PerformService(null)).Should().Throw<NotImplementedException>();
    }

    private class DependencyInjectionTestsAutoFacRegistrar : IAutoFacRegistrar
    {
        public void RegisterDependencies(ContainerBuilder containerBuilder)
        {
            containerBuilder.RegisterType<RootDependency>().As<IRootDependency>();
            containerBuilder.RegisterType<DependencyWithRootDependency>();

            containerBuilder.RegisterAssemblyTypes(Assembly.GetAssembly(GetType()))
                .AsClosedTypesOf(typeof(IServicer<>));
        }
    }
}

public interface IRootDependency
{
}

public class RootDependency : IRootDependency
{
}

public class DependencyWithRootDependency
{
    public IRootDependency RootDependency { get; }

    public DependencyWithRootDependency(IRootDependency rootDependency)
    {
        RootDependency = rootDependency;
    }
}

public interface IServiced
{
}

public interface IServicer<T>
    where T : IServiced
{
    void PerformService(T serviced);
}

public class ServiceRecipientA : IServiced
{
}

public class ServiceRecipientB : IServiced
{
}

public abstract class BaseServiceProvider<TServiced> : IServicer<TServiced>
    where TServiced : IServiced
{
    public abstract void PerformService(TServiced serviced);
}

public class ServiceAProvider : BaseServiceProvider<ServiceRecipientA>
{
    public override void PerformService(ServiceRecipientA serviced)
    {
        throw new NotImplementedException();
    }
}

public class ServiceBProvider : BaseServiceProvider<ServiceRecipientB>
{
    public override void PerformService(ServiceRecipientB serviced)
    {
        throw new NotImplementedException();
    }
}