index.js 288 B

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  1. 'use strict';
  2. module.exports = function (url) {
  3. if (typeof url !== 'string') {
  4. throw new TypeError('Expected a string, got ' + typeof url);
  5. }
  6. url = url.trim();
  7. if (/^\.*\/|^(?!localhost)\w+:/.test(url)) {
  8. return url;
  9. }
  10. return url.replace(/^(?!(?:\w+:)?\/\/)/, 'http://');
  11. };