Allow services to be overridden using ServiceCollection

src/LightInject.Microsoft.DependencyInjection.Tests/DefaultServiceTests.cs

@@ -0,0 +1,98 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Xunit;
+
+namespace LightInject.Microsoft.DependencyInjection.Tests;
+
+public class DefaultServiceTests
+{
+    [Fact]
+    public void ShouldOverrideDefaultRegistrationInServiceContainer()
+    {
+        var container = new ServiceContainer(options => options.WithMicrosoftSettings());
+        container.RegisterTransient<IFoo, Foo>();
+        var serviceCollection = new ServiceCollection();
+
+        serviceCollection.AddSingleton<IFoo, AnotherFoo>();
+
+        var provider = container.CreateServiceProvider(serviceCollection);
+
+        var foo = provider.GetRequiredService<IFoo>();
+
+        Assert.IsType<AnotherFoo>(foo);
+    }
+
+    [Fact]
+    public void ShouldOverrideNamedRegistrationInServiceContainer()
+    {
+        var container = new ServiceContainer(options => options.WithMicrosoftSettings());
+        container.RegisterTransient<IFoo, Foo>("Foo");
+        var serviceCollection = new ServiceCollection();
+
+        serviceCollection.AddSingleton<IFoo, AnotherFoo>();
+
+        var provider = container.CreateServiceProvider(serviceCollection);
+
+        var foo = provider.GetRequiredService<IFoo>();
+
+        Assert.IsType<AnotherFoo>(foo);
+    }
+
+    [Fact]
+    public void ShouldOverrideMultipleNamedRegistrationInServiceContainer()
+    {
+        var container = new ServiceContainer(options => options.WithMicrosoftSettings());
+        container.RegisterTransient<IFoo, Foo>("Foo1");
+        container.RegisterTransient<IFoo, Foo>("Foo2");
+        var serviceCollection = new ServiceCollection();
+
+        serviceCollection.AddSingleton<IFoo, AnotherFoo>();
+
+        var provider = container.CreateServiceProvider(serviceCollection);
+
+        var foo = provider.GetRequiredService<IFoo>();
+
+        Assert.IsType<AnotherFoo>(foo);
+    }
+
+    [Fact]
+    public void ShouldOverrideNamedAndDefaultRegistrationInServiceContainer()
+    {
+        var container = new ServiceContainer(options => options.WithMicrosoftSettings());
+        container.RegisterTransient<IFoo, Foo>();
+        container.RegisterTransient<IFoo, Foo>("Foo");
+        var serviceCollection = new ServiceCollection();
+
+        serviceCollection.AddSingleton<IFoo, AnotherFoo>();
+
+        var provider = container.CreateServiceProvider(serviceCollection);
+
+        var foo = provider.GetRequiredService<IFoo>();
+
+        Assert.IsType<AnotherFoo>(foo);
+    }
+
+
+    [Fact]
+    public void ShouldUseLast()
+    {
+        var container = new ServiceContainer(options => options.WithMicrosoftSettings());
+        container.RegisterTransient<IFoo, Foo>("Foo1");
+        container.RegisterTransient<IFoo, Foo>("Foo2");
+        var serviceCollection = new ServiceCollection();
+
+        serviceCollection.AddSingleton<IFoo, AnotherFoo>();
+
+        var provider = container.CreateServiceProvider(serviceCollection);
+
+        var foo = provider.GetRequiredService<IFoo>();
+
+        Assert.IsType<AnotherFoo>(foo);
+    }
+
+    public interface IFoo { }
+
+    public class Foo : IFoo { }
+
+    public class AnotherFoo : IFoo { }
+}

src/LightInject.Microsoft.DependencyInjection.Tests/ServiceProviderFactoryTests.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Text;
 using Microsoft.Extensions.DependencyInjection;
 using Xunit;
@@ -92,7 +93,7 @@ public void ShouldPickServiceWithoutServiceNameAsDefaultIfRegistered()
         {
             var serviceCollection = new ServiceCollection();
             serviceCollection.AddTransient<string>(p => "42");
-            var factory = new LightInjectServiceProviderFactory();
+            var factory = new LightInjectServiceProviderFactory(options => options.DefaultServiceSelector = serviceNames => serviceNames.SingleOrDefault(string.IsNullOrWhiteSpace) ?? serviceNames.Last());
             var container = factory.CreateBuilder(serviceCollection);
 
             container.Register<string>(f => "84");

src/LightInject.Microsoft.DependencyInjection/LightInject.Microsoft.DependencyInjection.cs

@@ -119,10 +119,24 @@ private static void RegisterServices(IServiceContainer container, Scope rootScop
     {
         var registrations = serviceCollection.Select(d => CreateServiceRegistration(d, rootScope)).ToList();
 
+        var servicesThatRequireNamePrefix = container.AvailableServices
+            .GroupBy(si => si.ServiceType)
+            .Select(g => new { ServiceType = g.Key, Prefix = g.OrderBy(g => g.ServiceName).Last().ServiceName })
+            .ToDictionary(g => g.ServiceType, g => g.Prefix);
+
+
+
         for (int i = 0; i < registrations.Count; i++)
         {
             ServiceRegistration registration = registrations[i];
-            registration.ServiceName = i.ToString("D8", CultureInfo.InvariantCulture.NumberFormat);
+            if (servicesThatRequireNamePrefix.TryGetValue(registration.ServiceType, out string prefix))
+            {
+                registration.ServiceName = prefix + i.ToString("D8", CultureInfo.InvariantCulture.NumberFormat);
+            }
+            else
+            {
+                registration.ServiceName = i.ToString("D8", CultureInfo.InvariantCulture.NumberFormat);
+            }
             container.Register(registration);
         }
     }
@@ -234,7 +248,8 @@ public static class ContainerOptionsExtensions
     /// <returns><see cref="ContainerOptions"/>.</returns>
     public static ContainerOptions WithMicrosoftSettings(this ContainerOptions options)
     {
-        options.DefaultServiceSelector = serviceNames => serviceNames.SingleOrDefault(string.IsNullOrWhiteSpace) ?? serviceNames.Last();
+        //options.DefaultServiceSelector = serviceNames => serviceNames.SingleOrDefault(string.IsNullOrWhiteSpace) ?? serviceNames.Last();
+        options.DefaultServiceSelector = serviceNames => serviceNames.Last();
         options.EnablePropertyInjection = false;
         options.EnableCurrentScope = false;
         options.EnableOptionalArguments = true;