server/src/Core/Identity/CustomIdentityServiceCollectionExtensions.cs

using System;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.DependencyInjection.Extensions;

namespace Microsoft.Extensions.DependencyInjection
{
    // ref: https://github.com/aspnet/Identity/blob/dev/src/Microsoft.AspNetCore.Identity/IdentityServiceCollectionExtensions.cs
    public static class CustomIdentityServiceCollectionExtensions
    {
        public static IdentityBuilder AddIdentityWithoutCookieAuth<TUser, TRole>(
            this IServiceCollection services)
            where TUser : class
            where TRole : class
        {
            return services.AddIdentityWithoutCookieAuth<TUser, TRole>(setupAction: null);
        }

        public static IdentityBuilder AddIdentityWithoutCookieAuth<TUser, TRole>(
            this IServiceCollection services,
            Action<IdentityOptions> setupAction)
            where TUser : class
            where TRole : class
        {
            // Hosting doesn't add IHttpContextAccessor by default
            services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            // Identity services
            services.TryAddScoped<IUserValidator<TUser>, UserValidator<TUser>>();
            services.TryAddScoped<IPasswordValidator<TUser>, PasswordValidator<TUser>>();
            services.TryAddScoped<IPasswordHasher<TUser>, PasswordHasher<TUser>>();
            services.TryAddScoped<ILookupNormalizer, UpperInvariantLookupNormalizer>();
            services.TryAddScoped<IRoleValidator<TRole>, RoleValidator<TRole>>();
            // No interface for the error describer so we can add errors without rev'ing the interface
            services.TryAddScoped<IdentityErrorDescriber>();
            services.TryAddScoped<ISecurityStampValidator, SecurityStampValidator<TUser>>();
            services.TryAddScoped<IUserClaimsPrincipalFactory<TUser>, UserClaimsPrincipalFactory<TUser, TRole>>();
            services.TryAddScoped<UserManager<TUser>, AspNetUserManager<TUser>>();
            services.TryAddScoped<SignInManager<TUser>, SignInManager<TUser>>();
            services.TryAddScoped<RoleManager<TRole>, AspNetRoleManager<TRole>>();

            if(setupAction != null)
            {
                services.Configure(setupAction);
            }

            return new IdentityBuilder(typeof(TUser), typeof(TRole), services);
        }
    }
}