Bug: D/I container selects the wrong class

[bart-degreed]

Description

I have an EF model with two entities: User and Content. Created controllers etc according to getting-started documentation.

I wanted to override filtering for Content, so created custom classes:

public class ContentResourceService : EntityResourceService<Content, long> { }
public class ContentEntityRepository : DefaultEntityRepository<Content, long> { }

Registered them as described at https://json-api-dotnet.github.io/#/layer-overview:

services.AddScoped<IResourceService<Content, long>, ContentResourceService>();
services.AddScoped<IEntityRepository<Content, long>, ContentEntityRepository>();

Now getting a list of content works as expected, but getting a list of users returns:

{
  "errors": [
    {
      "title": "InvalidCastException",
      "detail": "Unable to cast object of type 'ApiFrameworkTryout2.Controllers.ContentResourceService' to type 'JsonApiDotNetCore.Services.IResourceService`2[ApiFrameworkTryout2.Models.User,System.Int64]'.",
      "status": "500",
      "meta": {
        "stackTrace": [
          "System.InvalidCastException: Unable to cast object of type 'ApiFrameworkTryout2.Controllers.ContentResourceService' to type 'JsonApiDotNetCore.Services.IResourceService`2[ApiFrameworkTryout2.Models.User,System.Int64]'.\r",
          "   at object lambda_method(Closure, IServiceProvider, object[])\r",
          "   at Func<ControllerContext, object> Microsoft.AspNetCore.Mvc.Controllers.ControllerActivatorProvider.CreateActivator(ControllerActionDescriptor descriptor)+(ControllerContext controllerContext) => { }\r",
          "   at Func<ControllerContext, object> Microsoft.AspNetCore.Mvc.Controllers.ControllerFactoryProvider.CreateControllerFactory(ControllerActionDescriptor descriptor)+CreateController(ControllerContext controllerContext)\r",
          "   at Task Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)\r",
          "   at async Task Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync()\r",
          "   at async Task Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextExceptionFilterAsync()"
        ]
      }
    }
  ]
}

Version used: 4.0.0-alpha3

[maurei]

@bart-degreed there's nothing evidently wrong with the code you're sharing. If you can share your ApiFrameworkTryout2 repository or a similar small reproduction repository I can look into it further.

[bart-degreed]

I have created a minimal repro solution: ApiDependencyBugRepro.zip

See code in Startup.cs:

const bool showError = true;

if (showError)
{
    var mvcBuilder = services.AddMvcCore();

    services.AddJsonApi(options =>
    {
        options.Namespace = "api";
    }, mvcBuilder, discovery => discovery.AddCurrentAssembly());
}
else
{
    services.AddJsonApi<AppDbContext>(options =>
    {
        options.Namespace = "api";
    });
}

the first block throws, while the second (showError == false) works as expected. Moving my custom registrations above or below this code fragment does not seem to make a difference.

[maurei]

I ran your code and tried true and false for showError while triggered the /api/content route. In neither cases I can reproduce the error you reported. The constructor of both custom services are triggered.

Can you double check your repro?

Got it: api/user route. Investigating

[maurei]

The problem is an issue with the auto discovery not correctly determining to which resource your custom service belongs to. It has already been fixed in v4 in #591. You can check out the latest version of the master branch for this fix, I'm planning on doing an alpha release next week.

(There are a bunch of breaking changes among which an update to .net core 3, so I'm hoping to create a first draft of the migration guide before doing so)

Thanks for reporting the issue nevertheless :)

[bart-degreed]

Thanks for looking into this.