Github API ES6

GithubApi.js

export default class GithubApi{
  constructor(){
    this.host = 'https://api.github.com';
  }
  get(...params) {
    let args = [].slice.call(params);
    let callback = args.pop();
    let path = args.join('/');
    request('GET', path, callback);
  }
  
  request(method, path, callback) {
    
    return new Promise(function(resolve, reject){
      let request = new XMLHttpRequest();
          
      request.onload = function () {
        let result = request.responseText;
        if (~request.getResponseHeader('content-type').indexOf('json')) {
          result = JSON.parse(result);
        }
        resolve(result);
      };
  
      request.onerror = err => reject(err);
      
      request.open(method, this.host + '/' + path, true);
      request.send();
    });
  }
}