Using 204 as the status code when there's no resource. Closes GH-303

src/Http/Wolverine.Http.Tests/Bugs/bug_298_variable_named_event.cs

@@ -15,6 +15,7 @@ public async Task do_not_blow_up()
         var (tracked, result) = await TrackedHttpCall(x =>
         {
             x.Post.Json(new TelegramUpdated("foo")).ToUrl("/convert-book");
+            x.StatusCodeShouldBe(204);
         });
 
         tracked.Executed.SingleMessage<TelegramUpdated>()

src/Http/Wolverine.Http.Tests/respecting_fromservices_attribute.cs

@@ -27,7 +27,10 @@ public async Task concrete_type_decorated_with_NotBody_is_sourced_by_container()
         var recorder = Host.Services.GetRequiredService<Recorder>();
         recorder.Actions.Clear();
 
-        await Scenario(x => { x.Post.Url("/notbody"); });
+        await Scenario(x =>
+        {
+            x.Post.Url("/notbody");
+        });
 
         recorder.Actions.Single().ShouldBe("Called AttributesEndpoints.Post()");
     }

src/Http/Wolverine.Http.Tests/using_efcore.cs

@@ -24,7 +24,11 @@ public async Task using_db_context_without_outbox()
 
         var command = new CreateItemCommand { Name = "Isaiah Pacheco" };
 
-        await Scenario(x => { x.Post.Json(command).ToUrl("/ef/create"); });
+        await Scenario(x =>
+        {
+            x.Post.Json(command).ToUrl("/ef/create");
+            x.StatusCodeShouldBe(204);
+        });
 
         using var nested = Host.Services.As<IContainer>().GetNestedContainer();
         var context = nested.GetInstance<ItemsDbContext>();
@@ -40,7 +44,11 @@ public async Task using_db_context_with_outbox()
 
         var command = new CreateItemCommand { Name = "Jerick McKinnon" };
 
-        var (tracked, _) = await TrackedHttpCall(x => { x.Post.Json(command).ToUrl("/ef/publish"); });
+        var (tracked, _) = await TrackedHttpCall(x =>
+        {
+            x.Post.Json(command).ToUrl("/ef/publish");
+            x.StatusCodeShouldBe(204);
+        });
 
         using var nested = Host.Services.As<IContainer>().GetNestedContainer();
         var context = nested.GetInstance<ItemsDbContext>();

src/Http/Wolverine.Http.Tests/using_http_context_elements_in_routes.cs

@@ -16,7 +16,7 @@ protected async Task assertExecutesWithNoErrors(string url)
         await Scenario(x =>
         {
             x.Get.Url(url);
-            x.StatusCodeShouldBeOk();
+            x.StatusCodeShouldBe(204);
         });
     }
 
@@ -47,6 +47,7 @@ public async Task use_claims_principal()
         {
             x.ConfigureHttpContext(c => c.User = principal);
             x.Get.Url("/http/principal");
+            x.StatusCodeShouldBe(204);
         });
 
         HttpContextEndpoints.User.ShouldBeSameAs(principal);

src/Http/Wolverine.Http.Tests/using_marten.cs

@@ -31,7 +31,11 @@ public async Task use_marten_document_session_with_outbox()
     {
         var input = new Data { Id = Guid.NewGuid(), Name = "Jaylen Watson" };
 
-        var (tracked, _) = await TrackedHttpCall(x => { x.Post.Json(input).ToUrl("/publish/marten/message"); });
+        var (tracked, _) = await TrackedHttpCall(x =>
+        {
+            x.Post.Json(input).ToUrl("/publish/marten/message");
+            x.StatusCodeShouldBe(204);
+        });
 
         var published = tracked.Sent.SingleMessage<Data>();
         published.Id.ShouldBe(input.Id);

src/Http/Wolverine.Http/HttpChain.EndpointBuilder.cs

@@ -4,6 +4,7 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http.Metadata;
 using Microsoft.AspNetCore.Routing;
+using Wolverine.Http.Resources;
 
 namespace Wolverine.Http;
 
@@ -47,6 +48,12 @@ public RouteEndpoint BuildEndpoint()
             applier.Apply(builder, Method.Method);
         }
 
+        if (ResourceType == null)
+        {
+            builder.RemoveStatusCodeResponse(200);
+            builder.Metadata.Add(new ProducesResponseTypeMetadata{StatusCode = 204, Type = null});
+        }
+
         Endpoint = (RouteEndpoint?)builder.Build();
 
         return Endpoint;

src/Http/Wolverine.Http/HttpGraph.cs

@@ -22,6 +22,7 @@ public partial class HttpGraph : EndpointDataSource, ICodeFileCollection, IChang
 
     private readonly List<IResourceWriterPolicy> _writerPolicies = new()
     {
+        new EmptyBody204Policy(),
         new StatusCodePolicy(),
         new ResultWriterPolicy(),
         new StringResourceWriterPolicy(),

src/Http/Wolverine.Http/IHttpAware.cs

@@ -8,6 +8,7 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Metadata;
+using Wolverine.Http.Resources;
 
 namespace Wolverine.Http;
 
@@ -62,7 +63,7 @@ public static void PopulateMetadata(MethodInfo method, EndpointBuilder builder)
         builder.RemoveStatusCodeResponse(200);
 
         var create = new MethodCall(method.DeclaringType, method).Creates.FirstOrDefault()?.VariableType;
-        var metadata = new Metadata { Type = create, StatusCode = 201 };
+        var metadata = new ProducesResponseTypeMetadata { Type = create, StatusCode = 201 };
         builder.Metadata.Add(metadata);
     }
 
@@ -73,11 +74,4 @@ void IHttpAware.Apply(HttpContext context)
         context.Response.Headers.Location = Url();
         context.Response.StatusCode = 201;
     }
-
-    internal class Metadata : IProducesResponseTypeMetadata
-    {
-        public Type? Type { get; init; }
-        public int StatusCode { get; init; }
-        public IEnumerable<string> ContentTypes => new string[] { "application/json" };
-    }
 }

src/Http/Wolverine.Http/Resources/EmptyBody204Policy.cs

@@ -0,0 +1,38 @@
+using JasperFx.CodeGeneration;
+using JasperFx.CodeGeneration.Frames;
+using JasperFx.CodeGeneration.Model;
+using Microsoft.AspNetCore.Http;
+
+namespace Wolverine.Http.Resources;
+
+internal class EmptyBody204Policy : IResourceWriterPolicy
+{
+    public bool TryApply(HttpChain chain)
+    {
+        if (chain.ResourceType == null || chain.ResourceType == typeof(void))
+        {
+            chain.Postprocessors.Insert(0, new WriteEmptyBodyStatusCode());
+            return true;
+        }
+
+        return false;
+    }
+}
+
+internal class WriteEmptyBodyStatusCode : SyncFrame
+{
+    private Variable? _context;
+
+    public override void GenerateCode(GeneratedMethod method, ISourceWriter writer)
+    {
+        writer.WriteComment("Wolverine automatically sets the status code to 204 for empty responses");
+        writer.Write($"{_context!.Usage}.{nameof(HttpContext.Response)}.{nameof(HttpResponse.StatusCode)} = 204;");
+        Next?.GenerateCode(method, writer);
+    }
+
+    public override IEnumerable<Variable> FindVariables(IMethodVariables chain)
+    {
+        _context = chain.FindVariable(typeof(HttpContext));
+        yield return _context;
+    }
+}

src/Http/Wolverine.Http/Resources/ProducesResponseTypeMetadata.cs

@@ -0,0 +1,10 @@
+using Microsoft.AspNetCore.Http.Metadata;
+
+namespace Wolverine.Http.Resources;
+
+internal class ProducesResponseTypeMetadata : IProducesResponseTypeMetadata
+{
+    public Type? Type { get; init; }
+    public int StatusCode { get; init; }
+    public IEnumerable<string> ContentTypes => new string[] { "application/json" };
+}