Facebook SDK wrapper

facebook.js

import {facebookAppId} from '../../credentials.json'
/////////////////////////////////////////////////
function wrapFB(fb) {
  // PRIVATE
  /** 
   * Promise around FB.getLoginStatus method
   */
  const _getLoginStatus = () => new Promise((resolve) => {
    fb.getLoginStatus(response => resolve(response))
  })
  /** 
   * Promise around FB.login method 
   */
  const _login = () => new Promise((resolve, reject) => {
    fb.login(response => resolve(response), {
      scope: 'email,public_profile',
      return_scopes: true,
    })
  })
  /** 
   * Promise based workflow of Facebook login process.
   * First we check that the user hasn't already logged in.
   * If he is continue, else open the auth portal.
   * If the authentication is succesfull return the response,
   * else reject with the response. 
   */
  const login = () => _getLoginStatus()
    .then(response => {
      if (response.status === 'connected')
        return response
      return _login()
    })
    .then(response => {
      if (response.status === 'connected')
        return response
      return Promise.reject(response)
    })
  /** Retun object */
  return {
    login
  }
}
/////////////////////////////////////////////////
// Setup Facebook SDK asynchronously
/////////////////////////////////////////////////
// Instantiate a container for the wrapped SDK.
// This method will run after the SDK is downloaded.
let Facebook
window.fbAsyncInit = () => {
  FB.init({
    appId      : facebookAppId,
    status     : true,
    xfbml      : false,
    version    : 'v2.8'
  });
  // Store the wrapped SDK on the prev defined var
  Facebook = wrapFB(FB)
};
(function(d, s, id){
  var js, fjs = d.getElementsByTagName(s)[0];
  if (d.getElementById(id)) {return;}
  js = d.createElement(s); js.id = id;
  js.src = "//connect.facebook.net/en_US/sdk.js";
  fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));
/////////////////////////////////////////////////
// Export the wrapped SDK as a function so we can
// access it from other modules. This is necessary
// because it is defined asynchronously.
export default () => Facebook