New exception handler (#111)

* Added editing product after note recognized by photo

* Fill product form values after note recognized

* Fixed double toggle dialog bug

* Fix not closing dialog after edit

* Added isProblemDetailsError type guard

* Show error message from non successful recognize note response

* Handle OpenAI errors as ProblemDetails

* Refactor error handling, use Result pattern

* Handle empty ProblemDetails and unknown error responses

* Handle no food found on photo case

* Added new exception handler with error handling tests

* Removed unused folder

src/backend/src/FoodDiary.API/ErrorHandling/ExceptionHandler.cs

@@ -0,0 +1,43 @@
+using System;
+using System.ClientModel;
+using System.Threading;
+using System.Threading.Tasks;
+using FoodDiary.Domain.Exceptions;
+using Microsoft.AspNetCore.Diagnostics;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+
+namespace FoodDiary.API.ErrorHandling;
+
+public class ExceptionHandler(
+    ILogger<ExceptionHandler> logger,
+    IProblemDetailsService problemDetailsService) : IExceptionHandler
+{
+    public async ValueTask<bool> TryHandleAsync(
+        HttpContext httpContext,
+        Exception exception,
+        CancellationToken cancellationToken)
+    {
+        logger.LogError("{Exception}", exception);
+
+        var (statusCode, detail) = exception switch
+        {
+            ImportException e => (StatusCodes.Status400BadRequest, e.Message.Trim()),
+            ClientResultException e => (StatusCodes.Status500InternalServerError, e.Message.Trim()),
+            _ => (StatusCodes.Status500InternalServerError, "Something went wrong")
+        };
+
+        httpContext.Response.StatusCode = statusCode;
+
+        return await problemDetailsService.TryWriteAsync(new ProblemDetailsContext
+        {
+            HttpContext = httpContext,
+            Exception = exception,
+            ProblemDetails =
+            {
+                Title = "An error occurred",
+                Detail = detail
+            }
+        });
+    }
+}

src/backend/src/FoodDiary.API/Startup.cs

@@ -1,8 +1,8 @@
 using System.Reflection;
 using System.Threading.Tasks;
+using FoodDiary.API.ErrorHandling;
 using FoodDiary.API.Extensions;
 using FoodDiary.API.Logging;
-using FoodDiary.API.Middlewares;
 using FoodDiary.API.Options;
 using FoodDiary.Application.Extensions;
 using FoodDiary.Configuration;
@@ -113,6 +113,7 @@ public void ConfigureServices(IServiceCollection services)
 
         services.AddSerilog((provider, logger) => logger.Configure(provider));
         services.AddProblemDetails();
+        services.AddExceptionHandler<ExceptionHandler>();
 
         services.ConfigureCustomOptions(_configuration);
         services.Configure<ImportOptions>(_configuration.GetSection("Import"));
@@ -152,8 +153,8 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 c.SwaggerEndpoint("/swagger/v1/swagger.json", "FoodDiary API v1");
             });
         }
-
-        app.UseMiddleware<ExceptionHandlerMiddleware>();
+        
+        app.UseExceptionHandler();
         app.UseSpaStaticFiles();
         app.UseSerilogRequestLogging();
         app.UseRouting();

src/backend/src/FoodDiary.Domain/Exceptions/ImportException.cs

@@ -5,17 +5,4 @@ namespace FoodDiary.Domain.Exceptions;
 /// <summary>
 /// Represents errors that occur during diary import operations
 /// </summary>
-public class ImportException : Exception
-{
-    public ImportException()
-    {
-    }
-
-    public ImportException(string message) : base(message)
-    {
-    }
-
-    public ImportException(string message, Exception innerException) : base(message, innerException)
-    {
-    }
-}
+public class ImportException(string message) : Exception(message);

src/backend/tests/FoodDiary.ComponentTests/Scenarios/ErrorHandling/ErrorHandlingContext.cs

@@ -0,0 +1,51 @@
+using System.Net;
+using System.Net.Http.Json;
+using FoodDiary.ComponentTests.Infrastructure;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.TestHost;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace FoodDiary.ComponentTests.Scenarios.ErrorHandling;
+
+public class ErrorHandlingContext(FoodDiaryWebApplicationFactory factory, InfrastructureFixture infrastructure)
+    : BaseContext(factory, infrastructure)
+{
+    private HttpResponseMessage? _response;
+    private HttpStatusCode _statusCode;
+
+    public Task Given_application_is_broken_because_of_an_unhandled_exception(Exception exception)
+    {
+        Factory = Factory.WithWebHostBuilder(builder =>
+        {
+            builder.ConfigureTestServices(services =>
+            {
+                services.Configure<MvcOptions>(options =>
+                {
+                    options.Filters.Add(new FakeExceptionActionFilter(exception));
+                });
+            });
+        });
+
+        return Task.CompletedTask;
+    }
+
+    public async Task When_user_is_trying_to_access_resource(string resource)
+    {
+        _response = await ApiClient.GetAsync(resource);
+        _statusCode = _response.StatusCode;
+    }
+
+    public Task Then_response_has_status(HttpStatusCode status)
+    {
+        _statusCode.Should().Be(status);
+        return Task.CompletedTask;
+    }
+
+    public async Task Then_response_is_problem_details()
+    {
+        var problemDetails = await _response!.Content.ReadFromJsonAsync<ProblemDetails>();
+        problemDetails!.Status.Should().Be((int)_statusCode);
+        problemDetails.Title.Should().NotBeNullOrWhiteSpace();
+        problemDetails.Detail.Should().NotBeNullOrWhiteSpace();
+    }
+}

src/backend/tests/FoodDiary.ComponentTests/Scenarios/ErrorHandling/ErrorHandlingTests.cs

@@ -0,0 +1,24 @@
+using System.Net;
+using FoodDiary.ComponentTests.Infrastructure;
+
+namespace FoodDiary.ComponentTests.Scenarios.ErrorHandling;
+
+public class ErrorHandlingTests(FoodDiaryWebApplicationFactory factory, InfrastructureFixture infrastructure) :
+    ScenarioBase<ErrorHandlingContext>(factory, infrastructure)
+{
+    protected override ErrorHandlingContext CreateContext(
+        FoodDiaryWebApplicationFactory factory,
+        InfrastructureFixture infrastructure) => new(factory, infrastructure);
+
+    [Scenario]
+    public Task I_receive_unhandled_errors_in_problem_details_format()
+    {
+        var exception = new Exception("some error");
+
+        return Run(
+            c => c.Given_application_is_broken_because_of_an_unhandled_exception(exception),
+            c => c.When_user_is_trying_to_access_resource("/api/v1/auth/status"),
+            c => c.Then_response_has_status(HttpStatusCode.InternalServerError),
+            c => c.Then_response_is_problem_details());
+    }
+}

src/backend/tests/FoodDiary.ComponentTests/Scenarios/ErrorHandling/FakeExceptionActionFilter.cs

@@ -0,0 +1,15 @@
+using Microsoft.AspNetCore.Mvc.Filters;
+
+namespace FoodDiary.ComponentTests.Scenarios.ErrorHandling;
+
+public class FakeExceptionActionFilter(Exception exception) : IActionFilter
+{
+    public void OnActionExecuting(ActionExecutingContext context)
+    {
+        throw exception;
+    }
+
+    public void OnActionExecuted(ActionExecutedContext context)
+    {
+    }
+}