filter out the APIs being documented by NSwag in ASP.NET Core MVC

I am trying to filter out the APIs being documented by NSwag inside an ASP.NET Core MVC application but it seems to be failing so far. I used the following custom IActionDescriptorCollectionProvider which seems to be picked up by ASP.NET Core MVC but not by NSwag.

    public class CustomActionDescriptorCollectionProvider : IActionDescriptorCollectionProvider
    {
        private readonly ActionDescriptorCollectionProvider _actionDescriptorCollectionProvider;

        public CustomActionDescriptorCollectionProvider(IEnumerable<IActionDescriptorProvider> actionDescriptorProviders,
            IEnumerable<IActionDescriptorChangeProvider> actionDescriptorChangeProviders)
        {
            if (actionDescriptorProviders == null) throw new ArgumentNullException(nameof(actionDescriptorProviders));
            if (actionDescriptorChangeProviders == null) throw new ArgumentNullException(nameof(actionDescriptorChangeProviders));

            _actionDescriptorCollectionProvider = new ActionDescriptorCollectionProvider(actionDescriptorProviders, actionDescriptorChangeProviders);
        }

        public ActionDescriptorCollection ActionDescriptors
        {
            get
            {
                var filteredCollection = _actionDescriptorCollectionProvider.ActionDescriptors.Items.Where(descriptor =>
                {
                    return false;
                }).ToList();

                return new ActionDescriptorCollection(filteredCollection, _actionDescriptorCollectionProvider.ActionDescriptors.Version);
            }
        }
    }

Then, I registered this like below:

            services.AddSingleton<IActionDescriptorCollectionProvider, CustomActionDescriptorCollectionProvider>();

This is just for a sample as you can see it hides all the actions but with this I expected NSwag to document nothing.

What’s the recommended way to filter out APIs to be documented in NSwag based on a condition? I can see the SwaggerIgnoreAttribute but I cannot apply that based on a condition.

[RicoSuter]

See https://github.com/RSuter/NSwag/wiki/Middlewares

[RicoSuter]

AddSwagger() is only needed for the new UseSwagger*WithApiExplorer() methods