url-escape.js

module.exports = function escape(url) {
  if (typeof url !== 'string') {
    return url;
  }

  // If url is already wrapped in quotes, remove them
  if (/^['"].*['"]$/.test(url)) {
    url = url.slice(1, -1);
  }
  // Should url be wrapped?
  // See https://drafts.csswg.org/css-values-3/#urls
  if (/["'() \t\n]/.test(url)) {
    return '"' + url.replace(/"/g, '\\"').replace(/\n/g, '\\n') + '"';
  }

  return url;
};