MessagePublisherExtensions.cs

using UniRx;

namespace Development
{
    public static class MessagePublisherExtensions
    {
        public static void PublishWithBaseType<T>(this IMessagePublisher self, T message)
        {
            self.Publish(message);
            for (var baseType = typeof(T).BaseType; null != baseType; baseType = baseType.BaseType)
            {
                typeof(IMessagePublisher)
                    .GetMethod(nameof(IMessagePublisher.Publish))
                    .MakeGenericMethod(baseType)
                    .Invoke(self, new object[] {message});
            }
        }
    }
}