Nested Interfaces and Mega Classes

[chrstophr-wltrs]

Hi everyone 👋 I'm working on some integration tests for a handful of very large ASP.NET applications. In the source code, these endpoints are split up into "controllers", and I'm trying to have my test code somewhat mirror that. It also makes sense to have related methods in different files from a logical perspective. Let's say I have an "Admin" API and an "External" API. For the Admin API, I might have some interfaces in different files like this:

/* INotification.cs */
namespace Application.Admin;

public interface INotification
{
	[Get("/notification")]
	Task<IApiResponse<List<Notification>>> View();

	[Put("/notification/clear")]
	Task<IApiResponse> Clear();
}

/* IUser.cs */
namespace Application.Admin;

public interface IUser
{
	[Get("/user")]
	Task<IApiResponse<List<UserDetails>>> ViewAll();

	[Post("/user")]
	Task<IApiResponse<UserDetails>> Add([Body] UserDetails request);
}

And the External API would look like this:

/* INotification.cs */
namespace Application.External;

public interface INotification
{
	[Get("/notification/unread")]
	Task<IApiResponse<List<Notification>>> View();

	[Get("/notification/history")]
	Task<IApiResponse<List<Notification>>> ViewHistory();

	[Put("/notification/clear")]
	Task<IApiResponse> Clear();
}

/* IUser.cs */
namespace Application.External;

public interface IUser
{
	[Get("/user")]
	Task<IApiResponse<List<UserDetails>>> ViewAll();

	[Get("/user/{userId}")]
	Task<IApiResponse<UserDetails>> View(Guid userId);
}

Of course, when you have three or more interfaces with the same name in one project, Refit refuses to auto-generate implementations of those interfaces, even if they're in different namespaces.

One possible solution is to instead generate a single interface using partials:

/* Notification.cs */
namespace Application.External;

public partial interface IExternal
{
	[Get("/notification/unread")]
	Task<IApiResponse<List<Notification>>> ViewNotifications();

	[Get("/notification/history")]
	Task<IApiResponse<List<Notification>>> ViewNotificationHistory();

	[Put("/notification/clear")]
	Task<IApiResponse> ClearNotifications();
}

/* User.cs */
namespace Application.External;

public partial interface IExternal
{
	[Get("/user")]
	Task<IApiResponse<List<UserDetails>>> ViewAllUsers();

	[Get("/user/{userId}")]
	Task<IApiResponse<UserDetails>> ViewUser(Guid userId);
}

This means that every method must have a unique name across the entire API, which does end up feeling pretty redundant and silly.

I was wondering, does anyone know if there's some way to structure your interfaces such that you could consume it like this?

var adminApi = RestService.For<IAdmin>(baseUrl);
var notifications = await adminApi.INotification.View();
var users = await adminApi.IUser.ViewAll();

That's probably too specific for an auto-generator, but it seemed like it wouldn't hurt to ask.