code: function getSourcepath(filepath, htmlpath, rootpath) {
    if (!filepath) {
      return ['', ''];
    }
  
    if (isRemoteFilepath(filepath)) {
      const url = new URL(filepath);
  
      filepath = `./${url.pathname.slice(1).replace(RE_FORWARD_SLASH, '_')}`;
    }
    // Strip query params
    filepath = filepath.replace(RE_QUERY, '');
    // Relative path
    if (htmlpath && isRelativeFilepath(filepath)) {
      filepath = path.resolve(path.dirname(htmlpath), filepath);
      // Strip leading '/'
    } else if (filepath.indexOf('/') == 0) {
      filepath = filepath.slice(1);
    }
    if (filepath.includes('#')) {
      filepath = filepath.split('#');
    }
  
    return Array.isArray(filepath)
      ? [path.resolve(rootpath, filepath[0]), filepath[1]]
      : [path.resolve(rootpath, filepath), ''];
  }
docs: Retrieve resolved 'filepath' and optional anchor
  @param {String} filepath
  @param {String} htmlpath
  @param {String} rootpath
  @returns {Array}