amazon.co.jp の url から余分なものを取り去って綺麗にする

amazon.url.cleaner.user.js

// ==UserScript==
// @name           Amazon URL Cleaner
// @namespace      http://xr0038.net
// @description    Clean Amazon item URL
// @include        http://www.amazon.co.jp*/dp/*
// @include        https://www.amazon.co.jp*/dp/*
// @include        http://www.amazon.co.jp*/gp/*
// @include        https://www.amazon.co.jp*/gp/*
// @run-at document-start
// @version        1.2
// ==/UserScript==
if (document.URL.match(/(dp|gp\/product)\/[A-Z0-9]{10}/g)) {
  var newurl = document.URL.match(/https?:\/\/(|www\.)amazon\.(.+?)\//g) + document.URL.match(/(dp|gp\/product)\/[A-Z0-9]{10}/g);
  console.log(newurl);
  if (newurl != document.URL) location.replace(newurl);
}