{
  angular.module('meganote.signUp')
  .directive('signUp', () => {
    class SignUpController {
      constructor() {
        this.user = {};
      }
      submit() {
        console.log(this.user);
      }
    }
    return {
      scope: {},
      controller: SignUpController,
      controllerAs: 'vm',
      bindToController: true,
      templateUrl: '/sign-up/sign-up.html',
    };
  });
}

{
  angular.module('meganote.signUp')
  .directive('signUp', [
    'UsersService',
    (UsersService) => {

      class SignUpController {
        constructor() {
          this.user = {};
        }
        submit() {
          UsersService.create(this.user);
        }
      }

      return {
        scope: {},
        controller: SignUpController,
        controllerAs: 'vm',
        bindToController: true,
        templateUrl: '/sign-up/sign-up.html',
      };
    }
  ]);
}

Refactor SignUp directive to use UsersService.
Refactor SignUp directive to use UsersService.
