StackExchange Source Highlight: 転載サイトで StackOverflow, SuperUser等のStackExchangeサービスへのリンクをハイライトするUserScriptです（Chrome拡張機能）

highlight_stackexchange_source.user.js

// ==UserScript==
// @name         StackExchange Source Highlight
// @namespace    https://gist.github.com/syusui-s/67a81c0b7357e86b9531746bc84f22ce/
// @version      1.4.0
// @description  転載サイトで StackOverflow, SuperUser等のStackExchangeサービスへのリンクをハイライトします
// @license      CC0-1.0
// @author       syusui-s
// @match        https://codeday.me/*
// @match        https://*.coder.work/*
// @match        https://www.366service.com/jp/qa/*
// @match        https://www.codeflow.site/ja/article/*
// @match        https://www.it-swarm-ja.tech/ja/*
// @match        https://qastack.jp/*
// @match        https://python5.com/*
// @match        https://www.py4u.net/discuss/*
// @match        https://code.i-harness.com/*
// @match        https://stackoverrun.com/*
// @match        http://*.uwenku.com/*
// @match        https://steakrecords.com/*
// @match        https://living-sun.com/*
// @match        https://jpcloud.net/q/*
// @match        https://*.ojit.com/so/*
// @match        https://www.javaer101.com/*
// @match        https://www.debugcn.com/*
// @match        https://www.fixes.pub/*
// @match        https://cloud6.net/*
// @match        https://www.it-mure.jp.net/*
// @match        https://base64.work/*
// @match        https://webdevqa.jp.net/*
// @match        https://www.titanwolf.org/*
// @grant        none
// @run-at       document-end
// @downloadURL  https://gist.github.com/syusui-s/67a81c0b7357e86b9531746bc84f22ce/raw/highlight_stackexchange_source.user.js
// @updateURL    https://gist.github.com/syusui-s/67a81c0b7357e86b9531746bc84f22ce/raw/highlight_stackexchange_source.user.js
// ==/UserScript==

(function() {
  'use strict';

  function xPathSelectorAllUnordered(xpath, doc) {
    const xPathResult = document.evaluate(xpath, doc, null, XPathResult.UNORDERED_NODE_ITERATOR_TYPE);
    const results = [];
    for (;;) {
      const node = xPathResult.iterateNext();
      if (node == undefined) break;
      results.push(node);
    }
    return results;
  }

  const markClass = '__stackexchange_source_highlight__';
  const illegalLicenseOrigins = ['https://code.i-harness.com', 'https://living-sun.com/'];
  const query = 'a[href^="https://stackoverflow.com/"], a[href^="http://stackoverflow.com/"], a[href*="stackexchange.com/"], a[href^="https://superuser.com/"], a[href^="https://serverfault.com/"]';
  const xPathQuery = "//a[contains(text(), '原文') or contains(text(), 'ソース') or contains(text(), 'source') or contains(text(), 'Source')]";

  const style = document.createElement('style');
  style.textContent = `@keyframes blink { 65% { opacity: 0.0; } }`;
  document.head.appendChild(style);

  const linkStyle = {
    fontSize: '1em',
    color: 'red',
    animation: 'blink 1s step-end infinite',
    textDecoration: 'underline',
    fontWeight: 'bold',
    fontSize: '1.25em',
  };

  const sources = [...document.querySelectorAll(query)]
    .filter(elem => !elem.classList.contains(markClass))
    .filter((elem) => {
      // User page should be ignored
      if (/\/users\/\d+\/[\w-]+/.test(elem.href)) {
        return false;
      }
      return true;
    })
    .map((elem) => {
      // qastackはリンク先が間違っていることがあるので修正
      if (location.host === 'qastack.jp') {
        elem.href = elem.href.replace(/^https?:\/\/stackoverflow.com\/\/(.*)$/, '$1');
        elem.href = elem.href.replace(/^https?:\/\/qastack.jp\/\w+\/\d+\/(.*)$/, 'https://$1');
        elem.href = elem.href.replace(/^(https?:\/\/stackoverflow.com\/)(?!questions)\w+(\/\d+\/.*)$/, '$1questions$2');
      }
      return elem;
    });

  [...sources].forEach(elem => {
    Object.assign(elem.style, linkStyle);
    elem.appendChild(document.createTextNode('(転載元に移動)'));
    elem.classList.add(markClass);
  });

  const maybeSources = [...xPathSelectorAllUnordered(xPathQuery, document)]
    .filter(elem => !elem.classList.contains(markClass));

  [...maybeSources].forEach(elem => {
    Object.assign(elem.style, linkStyle, { color: 'darkorange' });
    elem.appendChild(document.createTextNode('(恐らく転載元)'));
    elem.classList.add(markClass);
  });

  const hasSource = (sources.length > 0 || maybeSources.length > 0) && !illegalLicenseOrigins.includes(location.origin);
  const warn = document.createElement('div');
  Object.assign(warn.style, {
    position: 'fixed',
    top: 0,
    padding: '10px',
    fontSize: '16px',
    textAlign: 'center',
    color: 'red',
    background: 'white',
    width: '100vw',
    border: '5px solid red',
    opacity: '0.9',
    zIndex: '2147483647',
  });
  const text = document.createElement('span');
  Object.assign(text.style, {
    animation: 'blink 1s ease-out infinite',
    fontSize: '32px',
    fontWeight: 'bold',
  });
  if (hasSource) {
    text.textContent = 'このサイトは転載サイトです。';
  } else {
    text.textContent = '⚠原典へのリンクが見つかりませんでした。ライセンス違反サイトの可能性があります。';
  }
  warn.appendChild(text);

  const createListFromLink = (el) => {
    const li = document.createElement('li');
    const link = document.createElement('a');
    Object.assign(link, { href: el.href, textContent: el.textContent });
    li.appendChild(link);
    return li;
  };
  const sourcesDiv = document.createElement('div');
  const sourcesElem = document.createElement('ul');
  sourcesDiv.appendChild(document.createTextNode('転載元へのリンク'));
  [...sources].map(createListFromLink).forEach((e) => sourcesElem.appendChild(e));
  sourcesDiv.appendChild(sourcesElem);
  sourcesDiv.appendChild(document.createTextNode('転載元の可能性があるリンク'));
  const maybeSourcesElem = document.createElement('ul');
  [...maybeSources].map(createListFromLink).forEach((e) => maybeSourcesElem.appendChild(e));
  sourcesDiv.appendChild(maybeSourcesElem);
  warn.appendChild(sourcesDiv);

  const br = document.createElement('br');
  warn.appendChild(br);

  const back = document.createElement('button');
  back.addEventListener('click', () => history.back());
  back.textContent = '🔙前のページに戻る';
  warn.appendChild(back);

  const proceed = document.createElement('button');
  proceed.addEventListener('click', () => warn.remove());
  proceed.textContent = '➡️閲覧を続ける';
  warn.appendChild(proceed);

  document.body.appendChild(warn);
})();

personal_blocklist.txt

code.i-harness.com hard
codeday.me hard
ja.coder.work hard
python5.com hard
qastack.jp hard
stackoverrun.com hard
www.366service.com hard
www.codeflow.site hard
www.it-swarm-ja.tech hard
ja.it-reply.net hard
ja.uwenku.com hard
living-sun.com hard
steakrecords.com hard
jpcloud.net hard
ja.ojit.com hard
www.javaer101.com hard
www.debugcn.com hard
www.py4u.net hard
www.fixes.pub hard
cloud6.net hard
www.it-mure.jp.net hard
base64.work hard
webdevqa.jp.net hard
www.titanwolf.org hard