angularjs http interceptor class (ES6) loses binding to 'this'

Question

I am building and AngularJS app using ES6 classes with traceur transpiling to ES5 in AMD format.

in my module I import the interceptor class and register it as a service

Answer 1

Working solution with arrow functions:

var AuthInterceptor = ($q, $injector, $log) => {
    'ngInject';

    var requestErrorCallback = request => {
        if (request.status === 500) {
          $log.debug('Something went wrong.');
        }
        return $q.reject(request);
    };

    var requestCallback = config => {
        const token = localStorage.getItem('jwt');

        if (token) {
            config.headers.Authorization = 'Bearer ' + token;
        }
        return config;
    };

    var responseErrorCallback = response => {
         // handle the case where the user is not authenticated
        if (response.status === 401 || response.status === 403) {
            // $rootScope.$broadcast('unauthenticated', response);
            $injector.get('$state').go('login');
       }
       return $q.reject(response);
    }

  return {
    'request':       requestCallback,
    'response':      config => config,
    'requestError':  requestErrorCallback,
    'responseError': responseErrorCallback,
  };
};

/***/
var config = function($httpProvider) {
    $httpProvider.interceptors.push('authInterceptor');
};

/***/    
export
default angular.module('services.auth', [])
    .service('authInterceptor', AuthInterceptor)
    .config(config)
    .name;