Simulating Error handling in ASP.NET Core

startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;

namespace ErrorDemo {
    public class Startup {
        public void Configure (IApplicationBuilder app) {

            app.UseDeveloperExceptionPage();

            app.UseExceptionHandler ("/error");

            app.Use (async (context, next) => {

                if (context.Request.Path == "/throw") {
                    throw new Exception ("Something went wrong!");
                }

                await context.Response.WriteAsync (Environment.NewLine + " No Error");
                await next.Invoke ();
            });

            app.Run (async (context) => {
                await context.Response.WriteAsync (Environment.NewLine + context.Request.Path);
            });
        }
    }
}