Add feature to return supplied ProblemDetails

src/Http/Wolverine.Http.Tests/Persistence/RequiredTodoAttributeEndpoint.cs

@@ -0,0 +1,27 @@
+using System.ComponentModel.DataAnnotations;
+using Alba;
+using IntegrationTests;
+using Marten;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Shouldly;
+using Wolverine.Marten;
+using Wolverine.Persistence;
+using WolverineWebApi.Todos;
+using Xunit.Abstractions;
+
+namespace Wolverine.Http.Tests.Persistence;
+
+public class RequiredTodoAttributeEndpoint {
+
+    public static async Task<(Todo2?, ProblemDetails)> LoadAsync(string id, IDocumentSession session)
+    {
+        var todo = await session.LoadAsync<Todo2>(id);
+        return (todo, todo != null ? WolverineContinue.NoProblems : new ProblemDetails { Detail = "Todo not found by id", Status = StatusCodes.Status404NotFound } );
+    }
+    // Should 404 w/ ProblemDetails on missing
+    [WolverineGet("/required/todo404required/{id}")]
+    public static Todo2 GetWithAttribute([Required] Todo2 todo) 
+        => todo;
+}

src/Http/Wolverine.Http.Tests/Persistence/reacting_to_required_attribute.cs

@@ -0,0 +1,65 @@
+using Alba;
+using IntegrationTests;
+using Marten;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Shouldly;
+using Wolverine;
+using Wolverine.Http;
+using Wolverine.Marten;
+using Xunit.Abstractions;
+
+public class reacting_to_required_attribute : IAsyncLifetime
+{
+    private readonly ITestOutputHelper _output;
+    private IAlbaHost theHost;
+
+    public reacting_to_required_attribute(ITestOutputHelper output)
+    {
+        _output = output;
+    }
+
+    public async Task InitializeAsync()
+    {
+        var builder = WebApplication.CreateBuilder([]);
+
+        // config
+        builder.Services.AddMarten(opts =>
+        {
+            // Establish the connection string to your Marten database
+            opts.Connection(Servers.PostgresConnectionString);
+            opts.DatabaseSchemaName = "onmissing";
+        }).IntegrateWithWolverine().UseLightweightSessions();
+
+        builder.Host.UseWolverine(opts => opts.Discovery.IncludeAssembly(GetType().Assembly));
+
+        builder.Services.AddWolverineHttp();
+
+        // This is using Alba, which uses WebApplicationFactory under the covers
+        theHost = await AlbaHost.For(builder, app =>
+        {
+            app.UseDeveloperExceptionPage();
+            app.MapWolverineEndpoints();
+        });
+    }
+
+    async Task IAsyncLifetime.DisposeAsync()
+    {
+        if (theHost != null) await theHost.StopAsync();
+    }
+
+    [Fact]
+    public async Task required_attribute_404_behavior_on_missing()
+    {
+        var tracked = await theHost.Scenario(x =>
+        {
+            x.Get.Url("/required/todo404required/nonexistent");
+            x.StatusCodeShouldBe(404);
+            x.ContentTypeShouldBe("application/problem+json");
+        });
+
+        var details = tracked.ReadAsJson<ProblemDetails>();
+        details.Detail.ShouldBe("Todo not found by id");
+    }
+}

src/Http/Wolverine.Http/Policies/SetStatusCodeAndReturnIfEntityIsNullFrame.cs

@@ -3,6 +3,7 @@
 using JasperFx.CodeGeneration.Model;
 using JasperFx.Core.Reflection;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
 
 namespace Wolverine.Http.Policies;
 
@@ -25,17 +26,19 @@ public SetStatusCodeAndReturnIfEntityIsNullFrame(Variable entity)
 
     public override void GenerateCode(GeneratedMethod method, ISourceWriter writer)
     {
+        ValueTypeReturnVariable.TupleVariable? problemDetailsVariable = null;
+        if (_entity?.Creator is MethodCall { ReturnVariable: ValueTypeReturnVariable vrv })
+            problemDetailsVariable = vrv.Inners.FirstOrDefault(v => v.Inner.VariableType == typeof(ProblemDetails));
         writer.WriteComment("404 if this required object is null");
-        writer.Write($"BLOCK:if ({_entity.Usage} == null)");
+        if (problemDetailsVariable != null)
+            writer.WriteComment($"Take no action if {problemDetailsVariable.Inner.Usage}.Status == 404");
+        writer.Write(
+            $"BLOCK:if ({_entity.Usage} == null{(problemDetailsVariable == null ? "" : $" && {problemDetailsVariable.Inner.Usage}.Status != 404")})");
         writer.Write($"{_httpResponse.Usage}.{nameof(HttpResponse.StatusCode)} = 404;");
         if (method.AsyncMode == AsyncMode.ReturnCompletedTask)
-        {
             writer.Write($"return {typeof(Task).FullNameInCode()}.{nameof(Task.CompletedTask)};");
-        }
         else
-        {
             writer.Write("return;");
-        }
 
         writer.FinishBlock();