Angular Factory wrong way

angularWrongWay.js

angular.module('shortly.services', [])

// use of arrow functions seems to break the Angular API
.factory('Links', ($http) => {
  const addOne = url => $http({
    method: 'POST',
    url: '/api/links',
    data: {
      url: url
    }
  });

  const getAll = () => $http({
    method: 'GET',
    url: '/api/links'
  })
    .then(res => {
      return res.data;
    });

  return {
    addOne,
    getAll
  };
})