ExceptionMiddleware.cs

using System;
using System.Threading.Tasks;
using ExceptionMiddleware.Errors;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;

namespace ExceptionMiddleware
{
    public class ExceptionMiddleware
    {
        #region Constructors

        public ExceptionMiddleware(JsonSerializerSettings jsonSerializerSettings, RequestDelegate next,
            IHostingEnvironment environment,
            ILogger<ExceptionMiddleware> logger)
        {
            _jsonSerializerSettings = jsonSerializerSettings;
            _next = next;
            _environment = environment;
            _logger = logger;
        }

        #endregion

        public async Task Invoke(HttpContext context)
        {
            try
            {
                await _next(context);
            }
            catch (InvalidRestOperationException invalidRestOperationException)
            {
                _logger.Log(LogLevel.Information, invalidRestOperationException,
                    "Exception Middleware caught an error");

                context.Response.StatusCode = invalidRestOperationException.ResponseCode;
                await
                    context.Response
                        .WriteAsync(JsonConvert.SerializeObject(new ExceptionDTO(invalidRestOperationException),
                            _jsonSerializerSettings));
            }
            catch (Exception exception)
            {
                _logger.Log(LogLevel.Error, exception,
                    "Exception Middleware caught an unhandled exception");
                context.Response.StatusCode = 500;

                if (!_environment.IsProduction())
                {
                    var ex = exception;

                    do
                    {
                        await context.Response.WriteAsync(ex.Message);
                        await context.Response
                            .WriteAsync("\n##########################################################################");
                        await context.Response.WriteAsync(ex.StackTrace);
                        await context.Response
                            .WriteAsync("\n--------------------------------------------------------------------------");
                        ex = ex.InnerException;
                    } while (ex != null);
                }
                else
                {
                    await context.Response.WriteAsync("Ups... Something bad happened :(");
                }
            }
        }

        #region Vars

        private readonly JsonSerializerSettings _jsonSerializerSettings;
        private readonly RequestDelegate _next;
        private readonly IHostingEnvironment _environment;
        private readonly ILogger<ExceptionMiddleware> _logger;

        #endregion
    }
}