Does exposing some methods of a class through an Interface break any SOLID design principle? [closed]

Question

I understand interface segregation and single responsibility principles guide against a class implementing methods or property it doesn't need. However, for the scenario described below where I have a User service with Login and Register methods, my Login Controller needs access to a single method (the login method). I have tried to hide the Register method by injecting a UserService object exposed through the ILogin interface.

Interfaces

public interface ILogin
{
   Task Login();
}
public interface IRegister
{
   Task Register();
}

and the UserService class;

public class UserService: IRegister, ILogin
{
   public Task Login()
   {
      //implementation logic here
   } 
   public Task Register()
   {
      //implementation logic here
   } 
}

the Login Controller client

public class LoginController : Controller
{
   private ILogin login;
   public Login Controller(ILogin login)
   {
      this.login = login;
   }
   [HttpPost]
   public IActionResult Login()
   {
      //implementation logic here for login.post
   } 
}

I would like to know if this implementation breaks any design principle or if it is an anti-pattern.

Answer 1

If you want to use just one method from your service in Controller, then it is okay to use interface ILogin.

ISP is how interface can be consumed. It means don’t depend on more than you need. That is there is no need LoginController to consume the following methods like Register().

ISP's goal is to hide unnecessary information. Why? To minimize coupling and dependency.

Read more about ISP here