Reddit Auto Translator

Automatically switches to the Japanese translation when opening a Reddit post that supports translation.
줄 바꿈
// ==UserScript==
// @name            Reddit Auto Translator
// @name:ja         Reddit自動翻訳
// @namespace       https://greasyfork.org/users/1324207
// @match           https://www.reddit.com/*
// @version         1.0
// @author          Lark8037
// @description     Automatically switches to the Japanese translation when opening a Reddit post that supports translation.
// @description:ja  翻訳対応済みのRedditの投稿を開いた際に自動で日本語翻訳版に切り替えます。
// @run-at          document-start
// @license         MIT
// @icon            https://reddit.com/favicon.ico
// ==/UserScript==

(()=>{
  'use strict';
  let l='';
  setInterval(()=>{
    let h=location.href;
    if(h===l)return;
    l=h;
    let u=new URL(h),p=u.pathname;
    if(!/^\/r\/[^/]+\/comments\//.test(p))return;
    let k='r_tl_'+p,s=sessionStorage,st=s.getItem(k),tl=u.searchParams.get('tl');
    if(tl=='ja'){
      if(+st>0&&Date.now()-st>10000)s.removeItem(k);
    }else if(st!='failed'){
      if(+st>0&&Date.now()-st<10000){
        s.setItem(k,'failed');
      }else{
        s.setItem(k,Date.now());
        u.searchParams.set('tl','ja');
        location.replace(u);
      }
    }
  },200);
})();