Program.cs

using System;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using AutoMapper.EntityFramework.Example;
using Microsoft.EntityFrameworkCore;

namespace EntityFramework.AutoMapper.WorkerService
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureServices((hostContext, services) =>
                {
                    services.AddAutoMapper(typeof(MapperProfile));
                    services.AddDbContext<ApplicationContext>(builder => builder.UseInMemoryDatabase(Guid.NewGuid().ToString()), ServiceLifetime.Singleton);
                    services.AddHostedService<Worker>();
                });
    }
}