.

README.md

@@ -44,3 +44,18 @@ builder.Services.ConfigureHttpJsonOptions(options => {
     };
 });
 ```
+
+## ProblemDetails에 TraceId 추가하기
+* https://stackoverflow.com/questions/76669903/problemdetails-response-does-not-contain-traceid-property
+```csharp
+builder.Services.AddProblemDetails(options =>
+    options.CustomizeProblemDetails = (context) =>
+    {
+        if (!context.ProblemDetails.Extensions.ContainsKey("traceId"))
+        { 
+            string? traceId = Activity.Current?.Id ?? context.HttpContext.TraceIdentifier;
+            context.ProblemDetails.Extensions.Add(new KeyValuePair<string, object?>("traceId", traceId));
+        }
+    }
+);
+```

src/WebApplicationMinimalApi8/EndpointFilters/ResponseAddTraceIdFilter.cs

@@ -1,35 +1,64 @@
 using System.Diagnostics;
 using System.Text.Json.Nodes;
 using System.Text.Json;
+using Microsoft.AspNetCore.Http.HttpResults;
+using Microsoft.Extensions.Options;
+using Microsoft.AspNetCore.Http.Json;
+using System.Net.Mime;
 
 namespace WebApplicationMinimalApi8.EndpointFilters;
 
 public class ResponseAddTraceIdFilter : IEndpointFilter
 {
-    public static JsonNode AddTraceId(object? value, string id)
-    {
-        var root = JsonSerializer.SerializeToNode(value)!.Root;
-
-        root["traceId"] = id;
-
-        return root;
-    }
-
     public async ValueTask<object?> InvokeAsync(EndpointFilterInvocationContext context, EndpointFilterDelegate next)
     {
         var id = Activity.Current?.Id ?? context.HttpContext.TraceIdentifier;
+        var serializerOptions = context.HttpContext.RequestServices.GetRequiredService<IOptions<JsonOptions>>().Value.SerializerOptions;
         var ret = await next(context);
 
         return ret switch
         {
-            IStatusCodeHttpResult c => c switch
-            {
-                IValueHttpResult v => Results.Text(AddTraceId(v.Value, id).ToJsonString(), "application/json", statusCode: c.StatusCode),
-                { } v => v
-            },
+            //ValidationProblem c => AddTraceIdForFluentValidation(c),
+            IValueHttpResult v => Results.Text
+            (
+                AddTraceId(v.Value).ToJsonString(serializerOptions),
+                contentType: v switch
+                {
+                    IContentTypeHttpResult c => c.ContentType,
+                    _ => "application/json"
+                },
+                statusCode: v switch
+                {
+                    IStatusCodeHttpResult c => c.StatusCode,
+                    _ => 200
+                }
+            ),
+            IResult v => Results.Text
+            (
+                $$"""{"traceId":"{{id}}"}""",
+                contentType: "application/json",
+                statusCode: v switch
+                {
+                    IStatusCodeHttpResult c => c.StatusCode,
+                    _ => 200
+                }
+            ),
+            { } v => Results.Text(AddTraceId(v).ToJsonString(serializerOptions), "application/json", statusCode: 200),
             _ => ret
         };
-    }
 
+        ValidationProblem AddTraceIdForFluentValidation(ValidationProblem v)
+        {
+            v.ProblemDetails.Extensions["traceId"] = id;
+            return v;
+        }
 
+        JsonNode AddTraceId(object? value)
+        {
+            var root = JsonSerializer.SerializeToNode(value, serializerOptions)!.Root;
+            root["traceId"] = id;
+
+            return root;
+        }
+    }
 }

src/WebApplicationMinimalApi8/ExceptionHandlers/GlobalExceptionHandler.cs

@@ -1,26 +1,16 @@
-using System.Diagnostics;
-using System.Text.Json;
 using Microsoft.AspNetCore.Diagnostics;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Http.Json;
-using Microsoft.AspNetCore.Mvc;
 
 namespace WebApplicationMinimalApi8.ExceptionHandlers;
 
 public sealed class GlobalExceptionHandler(ILogger<GlobalExceptionHandler> logger) : IExceptionHandler
 {
     public async ValueTask<bool> TryHandleAsync(HttpContext httpContext, Exception exception, CancellationToken cancellationToken)
     {
-        var traceId = Activity.Current?.Id ?? httpContext.TraceIdentifier;
         logger.LogError(exception, "Exception occurred: {Message}", exception.Message);
 
         await Results.Problem(
             title: exception.Message,
-            statusCode: StatusCodes.Status500InternalServerError,
-            extensions:  new Dictionary<string, object?>
-            {
-                ["traceId"] = traceId
-            }
+            statusCode: StatusCodes.Status500InternalServerError
         ).ExecuteAsync(httpContext);
 
         return true;

src/WebApplicationMinimalApi8/Program.cs

@@ -8,32 +8,40 @@
 using WebApplicationMinimalApi8.EndpointFilters;
 using WebApplicationMinimalApi8.ExceptionHandlers;
 using System.Linq;
+using System.Diagnostics;
+using System.Text.Json;
 
 var builder = WebApplication.CreateBuilder(args);
 
 builder.Services.AddEndpointsApiExplorer();
-builder.Services.AddSwaggerGen(c =>
-{
-    c.ExampleFilters();
-});
+builder.Services.AddSwaggerGen(c => c.ExampleFilters());
 builder.Services.AddSwaggerExamplesFromAssemblyOf<Program>();
-builder.Services.AddValidatorsFromAssemblyContaining<Program>();
-builder.AddFluentValidationEndpointFilter();
 builder.Services.ConfigureHttpJsonOptions(options => {
+    options.SerializerOptions.PropertyNamingPolicy = JsonNamingPolicy.CamelCase;
+    options.SerializerOptions.PropertyNameCaseInsensitive = false;
     options.SerializerOptions.WriteIndented = true;
-    options.SerializerOptions.IncludeFields = true;
     options.SerializerOptions.PreferredObjectCreationHandling = JsonObjectCreationHandling.Populate;
     options.SerializerOptions.TypeInfoResolver = new DefaultJsonTypeInfoResolver
     {
         Modifiers = { InterceptNullSetter }
     };
 });
+builder.Services.AddValidatorsFromAssemblyContaining<Program>();
+builder.AddFluentValidationEndpointFilter();
 
 if (builder.Environment.IsEnvironment("Best"))
 {
-    builder.Services.AddExceptionHandler<BadRequestExceptionHandler>();
     builder.Services.AddExceptionHandler<GlobalExceptionHandler>();
-    builder.Services.AddProblemDetails();
+    builder.Services.AddProblemDetails(options =>
+        options.CustomizeProblemDetails = (context) =>
+    {
+        if (!context.ProblemDetails.Extensions.ContainsKey("traceId"))
+        {
+            string? traceId = Activity.Current?.Id ?? context.HttpContext.TraceIdentifier;
+            context.ProblemDetails.Extensions.Add(new KeyValuePair<string, object?>("traceId", traceId));
+        }
+    }
+);
 }
 
 var app = builder.Build();
@@ -45,19 +53,21 @@
 {
     app.UseExceptionHandler();
 }
+var root = app.MapGroup("/")
+              .AddEndpointFilter<ResponseAddTraceIdFilter>()
+              .AddFluentValidationFilter();
+
 
-app.MapPost("/validate", (MessageDto message) => message)
-   .WithDescription("메시지를 검증합니다.")
-   .AddFluentValidationFilter()
-   .AddEndpointFilter<ResponseAddTraceIdFilter>()
-   .WithOpenApi();
+root.MapPost("/validate", (MessageDto message) => Results.Ok())
+    .WithDescription("메시지를 검증합니다.")
+    .WithOpenApi();
 
-app.MapGet("/500", () =>
-{
-    throw new Exception("이런 저런 에러가 났군요");
-})
-.WithName("InternalException")
-.WithOpenApi();
+root.MapGet("/500", () =>
+    {
+        throw new Exception("이런 저런 에러가 났군요");
+    })
+    .WithName("InternalException")
+    .WithOpenApi();
 
 app.Run();