PoC of ASP.NET Core MVC App in LinqPAD

Try-AspNetCoreMvc.linq

<Query Kind="Program">
  <NuGetReference>Microsoft.AspNetCore</NuGetReference>
  <NuGetReference>Microsoft.AspNetCore.Hosting</NuGetReference>
  <NuGetReference>Microsoft.AspNetCore.Mvc</NuGetReference>
  <NuGetReference>Microsoft.AspNetCore.Routing</NuGetReference>
  <NuGetReference>Microsoft.AspNetCore.StaticFiles</NuGetReference>
  <NuGetReference>Swashbuckle.AspNetCore</NuGetReference>
  <NuGetReference>Swashbuckle.AspNetCore.SwaggerGen</NuGetReference>
  <Namespace>Microsoft.AspNetCore</Namespace>
  <Namespace>Microsoft.AspNetCore.Builder</Namespace>
  <Namespace>Microsoft.AspNetCore.Hosting</Namespace>
  <Namespace>Microsoft.AspNetCore.Mvc</Namespace>
  <Namespace>Microsoft.AspNetCore.Mvc.Controllers</Namespace>
  <Namespace>Microsoft.AspNetCore.Mvc.Infrastructure</Namespace>
  <Namespace>Microsoft.Extensions.Configuration</Namespace>
  <Namespace>Microsoft.Extensions.DependencyInjection</Namespace>
  <Namespace>Microsoft.Extensions.Logging</Namespace>
  <Namespace>Swashbuckle.AspNetCore.Swagger</Namespace>
</Query>

// Didn't work. Because a controller here is a nested class in the UserQuery.
// And the standard method ControllerFeatureProvider.IsController don't treat it as a controller:
// https://github.com/aspnet/Mvc/blob/0d0aad41f501243f250b77613c015b4267e8c78d/src/Microsoft.AspNetCore.Mvc.Core/Controllers/ControllerFeatureProvider.cs#L53
// >
// > IsPublic returns false for nested classes, regardless of visibility modifiers
// :(
// Apparently, it's possible to supply a custom IsController, now it works.
// https://stackoverflow.com/questions/36680933/discovering-generic-controllers-in-asp-net-core

// It seems we can provide controllers dynamically:
// https://stackoverflow.com/questions/46156649/asp-net-core-register-controller-at-runtime
// https://docs.microsoft.com/en-us/aspnet/core/mvc/advanced/app-parts?view=aspnetcore-2.1
// https://andrewlock.net/controller-activation-and-dependency-injection-in-asp-net-core-mvc/
// but IMO it's getting too complicated for a simple LINQPad script.

// Also there was a problem with Swagger UI:
// System.MissingMethodException: Method not found: 'Void Microsoft.Net.Http.Headers.EntityTagHeaderValue..ctor(System.String)'.
// https://github.com/pmilet/playback/issues/3
// > To solve this problem: install Microsoft.AspNetCore.StaticFiles v2.0.0.0 nuget package

public static void Main(string[] args)
{
	var host = BuildWebHost(args);
	host.Run();
}

public static IWebHost BuildWebHost(string[] args) =>
	WebHost.CreateDefaultBuilder(args)
		.UseStartup<Startup>()
		.Build();

// Define other methods and classes here
public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

	public IConfiguration Configuration { get; }

	// This method gets called by the runtime. Use this method to add services to the container.
	public void ConfigureServices(IServiceCollection services)
	{
		services.AddMvc()
			.ConfigureApplicationPartManager(manager =>
			{
				manager.FeatureProviders.Add(new MyControllerFeatureProvider());
			});
		services.AddSwaggerGen(opts =>
			{
				opts.SwaggerDoc("v1", new Info { Title = "Test App", Version = "v1" });
			});
		services.AddLogging(lb => lb.AddDebug().AddConsole().SetMinimumLevel(LogLevel.Trace));
	}

	// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
	public void Configure(IApplicationBuilder app, IHostingEnvironment env)
	{
		app.UseMvc();
		app.UseSwagger();
		app.UseSwaggerUI(opts =>
			{
				opts.SwaggerEndpoint("/swagger/v1/swagger.json", "TEST APP V1");
			});
	}
}

public class MyControllerFeatureProvider : ControllerFeatureProvider
{
	protected override bool IsController(TypeInfo typeInfo)
	{
		var isController = base.IsController(typeInfo);
		if (!isController)
		{
			if (typeInfo.Name.EndsWith("Controller", StringComparison.OrdinalIgnoreCase) ||
				typeInfo.IsDefined(typeof(ControllerAttribute)))
			{
				isController = true;
				Console.WriteLine("Found an extra Controller: " + typeInfo.FullName);
			}
		}
		return isController;
	}
}

[Route("api/[controller]")]
public class TodoController : Controller
{
	string[] nums = { "zero", "one", "two", "three" };

	[HttpGet]
	public string[] GetAll()
	{
		return nums;
	}

	[HttpGet("{id}", Name = "GetTodo")]
	public ActionResult<string> GetById(int id)
	{
		if (id < 0 || nums.Length <= id)
		{
			return NotFound();
		}
		return nums[id];
	}
}

[Route("monitor")]
[Controller]
public class MonitorController : Controller
{
	private readonly IActionDescriptorCollectionProvider _provider;

	public MonitorController(IActionDescriptorCollectionProvider provider)
	{
		_provider = provider;
	}

	[HttpGet("routes")]
	public IActionResult GetRoutes()
	{
		var routes = _provider.ActionDescriptors.Items.Select(x => new
		{
			Action = x.RouteValues["Action"],
			Controller = x.RouteValues["Controller"],
			Name = x.AttributeRouteInfo.Name,
			Template = x.AttributeRouteInfo.Template
		}).ToList();
		return Ok(routes);
	}
}