bookmarklet to view file in rawgit.com

rawgit.js

javascript: (function() {
  let devDomain = 'rawgit.com';
  const GITHUB_API_URL = 'https://api.github.com';
  const REGEX_GIST_URL = /^https?:\/\/gist\.github\.com\/.+?\/([0-9a-f]+)(?:\/([0-9a-f]+))?/i;
  const REGEX_RAW_GIST_URL = /^https?:\/\/gist\.githubusercontent\.com\/(.+?\/[0-9a-f]+\/raw\/(?:[0-9a-f]+\/)?.+\..+)$/i;
  const REGEX_RAW_REPO_URL = /^https?:\/\/raw\.github(?:usercontent)?\.com\/(.+?)\/(.+?)\/(.+?)\/(.+)/i;
  const REGEX_REPO_URL = /^https?:\/\/github\.com\/(.+?)\/(.+?)\/(?!releases\/)(?:(?:blob|raw)\/)?(.+?)\/(.+)/i;
  formatUrl();
  
  function formatRawGistUrl(url) {
    location = url.replace(REGEX_RAW_GIST_URL, 'https://' + devDomain + '/$1');
  }

  function formatRawRepoUrl(url) {
    location = url.replace(REGEX_RAW_REPO_URL, 'https://' + devDomain + '/$1/$2/$3/$4');
  }

  function formatRepoUrl(url) {
    location = url.replace(REGEX_REPO_URL, 'https://' + devDomain + '/$1/$2/$3/$4');
  }

  function formatUrl() {
    let url = location.href;
    if (REGEX_RAW_REPO_URL.test(url)) {
       formatRawRepoUrl(url);
    } else if (REGEX_RAW_GIST_URL.test(url)) {
       formatRawGistUrl(url);
    } else if (REGEX_REPO_URL.test(url)) {
       formatRepoUrl(url);
    } else if (REGEX_GIST_URL.test(url)) {
       requestGistUrl(url);
    }
  }

  function requestGistUrl(url) {
    let matches = url.match(REGEX_GIST_URL);
    let apiUrl = GITHUB_API_URL + '/gists/' + matches[1] + (matches[2] ? '/' + matches[2] : '');
    return fetch(apiUrl)
      .then(res => res.json())
      .then(data => {
        let files = data && data.files;
        let filenames = files && Object.keys(data.files);
        if (!filenames || !filenames.length) {
          return null;
        }
        let rawUrl = files[filenames[0]] && files[filenames[0]].raw_url;
        if (rawUrl) {
          formatRawGistUrl(rawUrl);
        }
      });
  }

})()