feat: add service/impl register for AddHostedSingleton

CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - X10D: Added `TextWriter.WriteLineNoAlloc(long[, ReadOnlySpan<char>[, IFormatProvider]])`.
 - X10D: Added `TextWriter.WriteLineNoAlloc(ulong[, ReadOnlySpan<char>[, IFormatProvider]])`.
 - X10D: Added `string.ConcatIf`.
+- X10D.Hosting: Added support for service/implementation registration with `AddHostedSingleton`.
 - X10D.Unity: Added `RaycastHit.GetComponent` and `RaycastHit.TryGetComponent`.
 - X10D.Unity: Added `DebugUtility.DrawFunction`, and `DebugUtility.DrawUnjoinedPolyhedron` on which it relies.
 

X10D.Hosting/src/DependencyInjection/ServiceCollectionExtensions.cs

@@ -21,6 +21,21 @@ public static class ServiceCollectionExtensions
         return services.AddSingleton<IHostedService, TService>(provider => provider.GetRequiredService<TService>());
     }
 
+    /// <summary>
+    ///     Adds an <see cref="IHostedService" /> registration for the given type, while simultaneously adding it as a singleton.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection" /> to add the service to.</param>
+    /// <typeparam name="TService">The type of the service to add.</typeparam>
+    /// <typeparam name="TImplementation">The type of the implementation to use.</typeparam>
+    /// <returns>A reference to this instance after the operation has completed.</returns>
+    public static IServiceCollection AddHostedSingleton<TService, TImplementation>(this IServiceCollection services)
+        where TService : class, IHostedService
+        where TImplementation : class, TService
+    {
+        services.AddSingleton<TService, TImplementation>();
+        return services.AddSingleton<IHostedService, TService>(provider => provider.GetRequiredService<TService>());
+    }
+
     /// <summary>
     ///     Adds an <see cref="IHostedService" /> registration for the given type, while simultaneously adding it as a singleton.
     /// </summary>
@@ -32,4 +47,19 @@ public static class ServiceCollectionExtensions
         services.AddSingleton(type);
         return services.AddSingleton(provider => (IHostedService)provider.GetRequiredService(type));
     }
+
+    /// <summary>
+    ///     Adds an <see cref="IHostedService" /> registration for the given type, while simultaneously adding it as a singleton.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection" /> to add the service to.</param>
+    /// <param name="serviceType">The type of the service to register.</param>
+    /// <param name="implementationType">The type of the implementation to use.</param>
+    /// <returns>A reference to this instance after the operation has completed.</returns>
+    public static IServiceCollection AddHostedSingleton(this IServiceCollection services,
+        Type serviceType,
+        Type implementationType)
+    {
+        services.AddSingleton(serviceType, implementationType);
+        return services.AddSingleton(provider => (IHostedService)provider.GetRequiredService(serviceType));
+    }
 }