Mvc: Actions lost when referencing Microsoft.AspNetCore.Mvc in dependency

[jimmypc92]

When you have some library that references Microsoft.AspNetCore.Mvc such as in the following project.json

_ClassLibrary1 project.json_

{
  "version": "1.0.0-*",

  "dependencies": {
    "Microsoft.AspNetCore.Mvc": "1.0.0-rc2-final",
    "NETStandard.Library": "1.5.0-rc2-24027"
  },

  "frameworks": {
    "netstandard1.5": {
      "imports": "dnxcore50"
    }
  }
}

and you have an application that depends on MVC by referencing this library, it causes actions to not be added to the ActionDescriptorCollectionProvider.

This can be reproduced by the following steps:

1. Create an ASP.NET Core Web Application with the default web application template
   

1. Add a class library as a project
   

2. Change project.json of the class library to the content listed above in _ClassLibrary1 project.json_

3. Remove reference to Microsoft.AspNetCore.Mvc in web application project.json

{
  "userSecretsId": "{REMOVED}",

  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.0.0-rc2-3002702",
      "type": "platform"
    },
    "Microsoft.ApplicationInsights.AspNetCore": "1.0.0-rc2-final",
    "Microsoft.AspNetCore.Authentication.Cookies": "1.0.0-rc2-final",
    "Microsoft.AspNetCore.Diagnostics": "1.0.0-rc2-final",
    "Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore": "1.0.0-rc2-final",
    "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0-rc2-final",
    //"Microsoft.AspNetCore.Mvc": "1.0.0-rc2-final",
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.0.0-preview1-final",
      "type": "build"
    },
    "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0-rc2-final",
    "Microsoft.AspNetCore.Server.Kestrel": "1.0.0-rc2-final",
    "Microsoft.AspNetCore.StaticFiles": "1.0.0-rc2-final",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.0-rc2-final",
    "Microsoft.EntityFrameworkCore.Tools": {
      "version": "1.0.0-preview1-final",
      "type": "build"
    },
    "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0-rc2-final",
    "Microsoft.Extensions.Configuration.Json": "1.0.0-rc2-final",
    "Microsoft.Extensions.Configuration.UserSecrets": "1.0.0-rc2-final",
    "Microsoft.Extensions.Logging": "1.0.0-rc2-final",
    "Microsoft.Extensions.Logging.Console": "1.0.0-rc2-final",
    "Microsoft.Extensions.Logging.Debug": "1.0.0-rc2-final",
    "Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0-rc2-final",
    "Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
      "version": "1.0.0-preview1-final",
      "type": "build"
    },
    "Microsoft.VisualStudio.Web.CodeGenerators.Mvc": {
      "version": "1.0.0-preview1-final",
      "type": "build"
    }
  },

  "tools": {
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.0.0-preview1-final",
      "imports": "portable-net45+win8+dnxcore50"
    },
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": {
      "version": "1.0.0-preview1-final",
      "imports": "portable-net45+win8+dnxcore50"
    },
    "Microsoft.EntityFrameworkCore.Tools": {
      "version": "1.0.0-preview1-final",
      "imports": [
        "portable-net45+win8+dnxcore50",
        "portable-net45+win8"
      ]
    },
    "Microsoft.Extensions.SecretManager.Tools": {
      "version": "1.0.0-preview1-final",
      "imports": "portable-net45+win8+dnxcore50"
    },
    "Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
      "version": "1.0.0-preview1-final",
      "imports": [
        "portable-net45+win8+dnxcore50",
        "portable-net45+win8"
      ]
    }
  },

  "frameworks": {
    "netcoreapp1.0": {
      "imports": [
        "dotnet5.6",
        "dnxcore50",
        "portable-net45+win8"
      ]
    }
  },

  "buildOptions": {
    "emitEntryPoint": true,
    "preserveCompilationContext": true
  },

  "runtimeOptions": {
    "gcServer": true
  },

  "publishOptions": {
    "include": [
      "wwwroot",
      "Views",
      "appsettings.json",
      "web.config"
    ]
  },

  "scripts": {
    "prepublish": [ "npm install", "bower install", "gulp clean", "gulp min" ],
    "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  }
}

1. Add reference from web application to the class library.

The following can be used to verify there are no actions being found

app.UseMvc(routes =>
{
    routes.MapRoute(
        name: "default",
        template: "{controller=Home}/{action=Index}/{id?}");
});

if (app.ApplicationServices.GetRequiredService<IActionDescriptorCollectionProvider>().ActionDescriptors.Items.Count == 0) {
    throw new Exception("No actions found.");
}

[rynowak]

/cc @javiercn

[javiercn]

I believe this is a dupe of https://github.com/aspnet/Mvc/issues/4555
The workaround for the moment is to just reference Microsoft.AspNetCore.Mvc directly in your web app or in any class library that contains things like controllers and so on.

[Eilon]

Yup, dup of https://github.com/aspnet/Mvc/issues/4555.

[pranavkm]

@BillDines, you should be able to workaround this by explicitly registering your ClassLibrary as an application part:

In your startup:

C# services .AddMvc() .AddApplicationPart(typeof(ValuesControllerFromClassLib).Assembly)

I suspect this is an issue with how DependencyContext computes references for csproj based class libraries.

[BillDines]

@pranavkm - thanks, that fixes it! Sorry, I deleted my comment already and started a new issue #4983

[pranavkm]

That's alright. It'll help us to keep track of the underlying issue so that it works out of the box.