function wfUnsafeShort(ast, file, setting) {
  let msg = 'Do not use unsafe `HTTP://goo.gl/` links';
  visit(ast, 'link', function(node) {
    let parsedUrl = url.parse(node.url);
    let protocol = parsedUrl.protocol;
    let hostname = parsedUrl.hostname;
    if (hostname && hostname.toLowerCase() === 'goo.gl') {
      if (protocol && protocol.toLowerCase() === 'http:') {
        file.message(msg, node);
      }
    }
  });
}
Remark Lint Test - checks for unsecured shortlinks.

@param {Object} ast
@param {Object} file
@param {Object} setting