Question: Controller discovery across multiple assemblies using new routing system

[kimbell]

I have a class library containing a Controller currently working on 2.0. I'm in the process of migrating things over to 3.0 using preview 9.

My class library has a test project that sets up things using WebApplicationFactory. In 2.0 the controller in my class library was automatically discovered. With the new routing system, it cannot find the path handled by the controller.

This is how I've set things up in the test project. Am I missing something?

protected override void ConfigureWebHost(IWebHostBuilder webhostBuilder)
        {
            webhostBuilder
                .UseContentRoot(Directory.GetCurrentDirectory())
                .UseDefaultServiceProvider(p => p.ValidateScopes = true)
                .ConfigureServices((context, services) =>
                    {
                        services.AddControllers();
                    })
                .Configure(appBuilder =>
                {
                    appBuilder.UseRouting();
                    appBuilder.UseEndpoints(config =>
                    {
                        config.MapControllers();
                    });
                });
        }
´´´

[kimbell]

I found out that

services.AddControllers().AddApplicationPart(typeof(MyController).Assembly);

makes things work, but is this the correct way or am I seeing the result of a side effect?

[mkArtakMSFT]

@pranavkm can you please confirm this approach is the right one? Thanks.

[mkArtakMSFT]

Also, is this potential 3.0 regression?

[pranavkm]

@kimbell is this a previously compiled library that wasn't recompiled using a 3.0 SDK?

[kimbell]

I'm in the process of recompiling our libraries against netcoreapp3.0 when I came across this, so it's not a 2.0 precompiled library.

My solution contains two projects; my library and a test project; both target netcoreapp3.0. In my library I have a controller that I want to automatically expose to anyone that uses it. When running tests that target the url of the controller, they fail due to a 404.

Since 2.0 automatically made all controllers in all referenced assemblies available, it's something we have used in multiple places. If things need to change due to the new routing system, so be it. I'm trying to figure out the correct way of doing this without introducing side-effects that can cause problems later on.

[mkArtakMSFT]

@kimbell please provide a minimal repro project for us to investigate this further.

[kimbell]

Common.Caching.zip
I've copied my original code and stripped it down to a minimum.

The test projects has 3 tests.
1 calls controller in test project
2 calls controller in main project (fails)
3 calls controller in main project, but uses AddApplicationPart()