Angular.js directive to get user gravatar from user email

angular.gravatar.directive.js

// npm install md5 --save
import md5 from 'md5';

let gravatarModule = angular.module('gravatar', [])
  .directive('gravatar', () => {

    const DEFAULT_AVATAR = "http://www.gravatar.com/avatar/000?s=200";
    const EMAIL_REGEX = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;

    let isEmail = (email) => EMAIL_REGEX.test(email);

    let getGravatarUrl = (email) => isEmail(email) ? `http://www.gravatar.com/avatar/${ md5(email) }.jpg?s=200` : DEFAULT_AVATAR;

    let link = (scope) => scope.url = getGravatarUrl(scope.email);

    return {
      template: `<img ng-src="{{ url }}">`,
      restrict: 'EA',
      replace: true,
      scope: { email: '=' },
      link
    }
  }).name;

export default gravatarModule