catch promise error and retry .

promise-retry.js

const debug = require('debug')('promise-retry');
/**
 * [promise-retry:  catch promise error and retry]
 * @param  {[type]} task    [description]
 * @param  {[type]} n       [description]
 * @param  {[type]} timeout [description]
 * @return {[type]}         [description]
 * @source https://gist.github.com/song940/6e3e1ec0380956006cd1
 */
module.exports = function retry(task, n, timeout){
  var timeouts = [];
  if(/array/i.test(({}).toString.call(n))){
    timeouts = n;
  }else{
    while(n--) timeouts.push(timeout || 1000);
  }
  return new Promise(function(accept, reject){
    (function fn(){
      task(this).then(accept, function(err){
        if(timeouts.length){
          timeout = timeouts.shift();
          debug('%ss after retry', timeout / 1000);
          setTimeout(fn, timeout);
        } else reject(err);
      });
    })();
  });
}