Refactor ExceptionHandlingMiddleware and update dependencies

Rewrote the `ExceptionHandlingMiddleware` class to improve structure and functionality, changing its namespace to `DigitalData.Core.Exceptions`. Updated the constructor to support a nullable logger and implemented null-conditional logging for unhandled exceptions. Added new package references in `DigitalData.Core.Exceptions.csproj` for `Microsoft.AspNetCore.Http.Abstractions` and `Microsoft.Extensions.Logging.Abstractions`. Introduced a new `DependencyInjection` class to register the middleware in the application's pipeline.

DigitalData.Core.Exceptions/DependencyInjection.cs

@@ -0,0 +1,12 @@
+using Microsoft.AspNetCore.Builder;
+
+namespace DigitalData.Core.Exceptions;
+
+public static class DependencyInjection
+{
+    public static IApplicationBuilder UseExceptionHandlingMiddleware(this IApplicationBuilder app)
+    {
+        app.UseMiddleware<ExceptionHandlingMiddleware>();
+        return app;
+    }
+}

DigitalData.Core.Exceptions/DigitalData.Core.Exceptions.csproj

@@ -6,4 +6,9 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.3.0" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.5" />
+  </ItemGroup>
+
 </Project>

DigitalData.Core.Exceptions/ExceptionHandlingMiddleware.cs

@@ -1,6 +1,5 @@
-namespace DigitalData.Core.API;
+namespace DigitalData.Core.Exceptions;
 
-using DigitalData.Core.Exceptions;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 using System.Net;
@@ -14,14 +13,14 @@ using System.Text.Json;
 public class ExceptionHandlingMiddleware
 {
     private readonly RequestDelegate _next;
-    private readonly ILogger<ExceptionHandlingMiddleware> _logger;
+    private readonly ILogger<ExceptionHandlingMiddleware>? _logger;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="ExceptionHandlingMiddleware"/> class.
     /// </summary>
     /// <param name="next">The next middleware in the request pipeline.</param>
     /// <param name="logger">The logger instance for logging exceptions.</param>
-    public ExceptionHandlingMiddleware(RequestDelegate next, ILogger<ExceptionHandlingMiddleware> logger)
+    public ExceptionHandlingMiddleware(RequestDelegate next, ILogger<ExceptionHandlingMiddleware>? logger = null)
     {
         _next = next;
         _logger = logger;
@@ -51,7 +50,7 @@ public class ExceptionHandlingMiddleware
     /// <param name="exception">The exception that occurred.</param>
     /// <param name="logger">The logger instance for logging the exception.</param>
     /// <returns>A task that represents the asynchronous operation.</returns>
-    private static async Task HandleExceptionAsync(HttpContext context, Exception exception, ILogger logger)
+    private static async Task HandleExceptionAsync(HttpContext context, Exception exception, ILogger? logger = null)
     {
         context.Response.ContentType = "application/json";
 
@@ -70,7 +69,7 @@ public class ExceptionHandlingMiddleware
                 break;
 
             default:
-                logger.LogError(exception, "Unhandled exception occurred.");
+                logger?.LogError(exception, "Unhandled exception occurred.");
                 context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
                 message = "An unexpected error occurred.";
                 break;