Singleton helper for DI

SingletonService.cs

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;

public interface ISingletonService<out TService>
{
    TService Serivce { get; }
}

public static class SingletonServiceHelper
{
    /// <summary>
    /// Allows to resolve <see cref="ISingletonService{}"/> from the <see cref="IServiceProvider"/>.
    /// </summary>
    /// <param name="services"></param>
    /// <returns></returns>
    public static IServiceCollection UseSingletonService(this IServiceCollection services)
    {
        ThrowIfNull(services);
        services.TryAddSingleton(typeof(ISingletonService<>), typeof(SingletonService<>));
        return services;
    }

    sealed class SingletonService<T>(T serivce) : ISingletonService<T>
    {
        public T Serivce { get; } = serivce;
    }

    /// <summary>
    /// Use <see cref="ISingletonService{}"/> to get the root <see cref="IServiceProvider"/>.
    /// </summary>
    /// <param name="serviceProvider"></param>
    /// <returns></returns>
    public static IServiceProvider GetRootServiceProvider(this IServiceProvider serviceProvider)
    {
        ThrowIfNull(serviceProvider);
        return serviceProvider.GetRequiredService<ISingletonService<IServiceProvider>>().Serivce;
    }

    public static bool IsRootServiceProvider(this IServiceProvider serviceProvider)
    {
        ThrowIfNull(serviceProvider);
        return ReferenceEquals(
            serviceProvider,
            serviceProvider.GetRequiredService<ISingletonService<IServiceProvider>>().Serivce);
    }

    /// <summary>
    /// Ensure the <paramref name="serviceProvider"/> is a scoped <see cref="IServiceProvider"/>.
    /// </summary>
    /// <param name="serviceProvider"></param>
    /// <exception cref="InvalidOperationException"></exception>
    public static void CheckScoped(this IServiceProvider serviceProvider)
    {
        if (serviceProvider.IsRootServiceProvider())
            throw new InvalidOperationException();
    }
}