Short 'hash' ID generator.

hashid.js

'use strict';

const ALPHABET = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-+';
const ALPHABET_LENGTH = ALPHABET.length;
const ID_LENGTH = 8;
const UNIQUE_RETRIES = 9999;

let HashID = {};

HashID.generate = function () {
  let rtn = '';
  for (let i = 0; i < ID_LENGTH; i++) {
    rtn += ALPHABET.charAt(Math.floor(Math.random() * ALPHABET_LENGTH));
  }
  return rtn;
};

HashID.generateUnique = function (previous) {
  previous = previous || [];
  let retries = 0;
  let id;

  while (!id && retries < UNIQUE_RETRIES) {
    id = HashID.generate();
    if (previous.indexOf(id) !== -1) {
      id = null;
      retries++;
    }
  }
  return id;
};

module.exports = HashID;