NikitaChizhov

internal interface IExampleService
{
    Task VeryImportantWorkAsync(int additionalSecondsToWait);
}

internal sealed class ExampleService : IExampleService
{
    private readonly IImportantDataProvider _dataProvider;

    public ExampleService(IImportantDataProvider dataProvider)

NikitaChizhov

internal interface IImportantDataProvider
{
    TimeSpan GetTimeToWait();
}

internal sealed class ImportantDataProvider : IImportantDataProvider
{
    /// <inheritdoc />
    public TimeSpan GetTimeToWait() => TimeSpan.FromSeconds(2);
}

NikitaChizhov

internal sealed class ExampleServiceClassicDecorator : IExampleService
{
    private readonly IExampleService _decorated;

    private readonly ILogger<ExampleServiceClassicDecorator> _logger;

    public ExampleServiceClassicDecorator(IExampleService decorated, 
        ILogger<ExampleServiceClassicDecorator> logger)
    {
        _decorated = decorated;

NikitaChizhov

public static IServiceCollection Decorate<TInterface, TDecorator>(this IServiceCollection services)
    where TInterface : class
    where TDecorator : class, TInterface
{
    var objectFactory = ActivatorUtilities.CreateFactory(
        typeof(TDecorator),
        new[] { typeof(TInterface) });

    // Save all descriptors that needs to be decorated into a list.
    var descriptorsToDecorate = services

NikitaChizhov

void ConfigureServices(IServiceCollection services)
{
    services
        .AddLogging(configure =>
        {
            configure.AddConsole();
            configure.SetMinimumLevel(LogLevel.Information);
        })
        .AddSingleton<IImportantDataProvider, ImportantDataProvider>()
        .AddSingleton<IExampleService>(sp =>

NikitaChizhov

public void ConfigureServices(IServiceCollection services)
{
    services
        .AddLogging(configure =>
        {
            configure.AddConsole();
            configure.SetMinimumLevel(LogLevel.Information);
        })
        .AddSingleton<IImportantDataProvider, ImportantDataProvider>()
        .AddSingleton<IExampleService, ExampleService>()

NikitaChizhov

internal class DispatchProxyEmptyDecorator<TDecorated> : DispatchProxy
{
    private TDecorated _decorated;

    protected override object Invoke(MethodInfo targetMethod, object[] args)
    {
            var result = targetMethod.Invoke(_decorated, args);
            return result;
    }

NikitaChizhov

internal class DispatchProxyMinimalLoggingDecorator<TDecorated> : DispatchProxy
{
    private TDecorated _decorated;

    private ILogger<DispatchProxyLoggingDecorator<TDecorated>> _logger;

    protected override object Invoke(MethodInfo targetMethod, object[] args)
    {
        try
        {

NikitaChizhov

internal class DispatchProxyLoggingDecorator<TDecorated> : DispatchProxy
{
    private TDecorated _decorated;

    private ILogger<DispatchProxyLoggingDecorator<TDecorated>> _logger;

    protected override object Invoke(MethodInfo targetMethod, object[] args)
    {
        try
        {

NikitaChizhov

internal static class ServiceCollectionsExtensions
{
    public static IServiceCollection DecorateWithDispatchProxy<TInterface, TProxy>(this IServiceCollection services)
        where TInterface : class
        where TProxy : DispatchProxy
    {
        MethodInfo createMethod;
        try
        {
            createMethod = typeof(TProxy)