MapShortCircuit causes runtime exceptions in app published as native AOT

[DamianEdwards]

Using MapShortCircuit in an app that's published native AOT results in an exception on first request when the endpoint itself is built:

fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HMQ7EGDA44U5", Request id "0HMQ7EGDA44U5:00000001": An unhandled exception was thrown by the application.
      System.NotSupportedException: Cannot retrieve a MethodInfo for this delegate because the method it targeted (Microsoft.AspNetCore.Routing.RouteShortCircuitEndpointRouteBuilderExtensions.<>c.<.cctor>b__3_0(HttpContext)) was not enabled for metadata.
         at Internal.Reflection.Extensions.NonPortable.DelegateMethodInfoRetriever.GetDelegateMethodInfo(Delegate) + 0x34f
         at Microsoft.AspNetCore.Routing.RouteEndpointDataSource.CreateRouteEndpointBuilder(RouteEndpointDataSource.RouteEntry, RoutePattern, IReadOnlyList`1, IReadOnlyList`1) + 0x42e
         at Microsoft.AspNetCore.Routing.RouteEndpointDataSource.GetGroupedEndpoints(RouteGroupContext) + 0xb4
         at Microsoft.AspNetCore.Routing.RouteGroupBuilder.GroupEndpointDataSource.GetGroupedEndpointsWithNullablePrefix(RoutePattern, IReadOnlyList`1, IReadOnlyList`1, IServiceProvider) + 0x58
         at Microsoft.AspNetCore.Routing.RouteGroupBuilder.GroupEndpointDataSource.get_Endpoints() + 0x3f
         at Microsoft.AspNetCore.Routing.CompositeEndpointDataSource.CreateEndpointsUnsynchronized() + 0x6c
         at Microsoft.AspNetCore.Routing.CompositeEndpointDataSource.EnsureEndpointsInitialized() + 0x4c
         at Microsoft.AspNetCore.Routing.CompositeEndpointDataSource.get_Endpoints() + 0x10
         at Microsoft.AspNetCore.Routing.DataSourceDependentCache`1.Initialize() + 0x44
         at System.Threading.LazyInitializer.EnsureInitializedCore[T](T&, Boolean&, Object&, Func`1) + 0x43
         at Microsoft.AspNetCore.Routing.Matching.DataSourceDependentMatcher..ctor(EndpointDataSource, DataSourceDependentMatcher.Lifetime, Func`1) + 0x96
         at Microsoft.AspNetCore.Routing.Matching.DfaMatcherFactory.CreateMatcher(EndpointDataSource) + 0x61
         at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.InitializeCoreAsync() + 0x8a
      --- End of stack trace from previous location ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() + 0x20
         at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task) + 0xb2
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task) + 0x42
         at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.<<Invoke>g__AwaitMatcher|9_0>d.MoveNext() + 0xc1
      --- End of stack trace from previous location ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() + 0x20
         at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task) + 0xb2
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.<ProcessRequests>d__238`1.MoveNext() + 0x460

This is due to MapShortCircuit using a compiler generated delegate as the RequestDelegate and native AOT not supporting getting MethodInfo on compiler generated delegates (see dotnet/runtime#85042):

aspnetcore/src/Http/Routing/src/ShortCircuit/RouteShortCircuitEndpointRouteBuilderExtensions.cs

Line 14 in 1b78513

private static readonly RequestDelegate _shortCircuitDelegate = (context) => Task.CompletedTask;

Repro

1. Create an ASP.NET Core project using the "API' project template and enabled for native AOT publish: dotnet new api --aot
2. Add a call to app.MapShortCircuit(StatusCodes.Status404NotFound, "/favicon.ico"), e.g.:

   using System.Text.Json.Serialization;
   using ShortCircuitNativeAot;
   
   var builder = WebApplication.CreateSlimBuilder(args);
   builder.Logging.AddConsole();
   
   builder.Services.ConfigureHttpJsonOptions(options =>
   {
       options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default);
   });
   
   var app = builder.Build();
   
   app.MapShortCircuit(StatusCodes.Status404NotFound, "/favicon.ico");
   
   var sampleTodos = TodoGenerator.GenerateTodos().ToArray();
   
   var todosApi = app.MapGroup("/todos");
   todosApi.MapGet("/", () => sampleTodos);
   todosApi.MapGet("/{id}", (int id) =>
       sampleTodos.FirstOrDefault(a => a.Id == id) is { } todo
           ? Results.Ok(todo)
           : Results.NotFound());
   
   app.Run();
   
   [JsonSerializable(typeof(Todo[]))]
   internal partial class AppJsonSerializerContext : JsonSerializerContext
   {
   
   }

3. Publish the project: dotnet publish
4. Run the published app, e.g.: .\bin\Release\net8.0\win-x64\publish\ShortCircuitNativeAot.exe
5. Make a request to the app on http://localhost:5000

[MichalStrehovsky]

This is a compiler bug. To temporarily work around, disable optimization that is causing this by adding:

  <ItemGroup>
    <IlcArg Include="--nopreinitstatics" />
  </ItemGroup>