axios/lib/urlIsSameOrigin.js

'use strict';

var msie = /(msie|trident)/i.test(navigator.userAgent);
var utils = require('./utils');
var urlParsingNode = document.createElement('a');
var originUrl = urlResolve(window.location.href);

/**
 * Parse a URL to discover it's components
 *
 * @param {String} url The URL to be parsed
 * @returns {Object}
 */
function urlResolve(url) {
  var href = url;

  if (msie) {
    // IE needs attribute set twice to normalize properties
    urlParsingNode.setAttribute('href', href);
    href = urlParsingNode.href;
  }

  urlParsingNode.setAttribute('href', href);

  // urlParsingNode provides the UrlUtils interface - http://url.spec.whatwg.org/#urlutils
  return {
    href: urlParsingNode.href,
    protocol: urlParsingNode.protocol ? urlParsingNode.protocol.replace(/:$/, '') : '',
    host: urlParsingNode.host,
    search: urlParsingNode.search ? urlParsingNode.search.replace(/^\?/, '') : '',
    hash: urlParsingNode.hash ? urlParsingNode.hash.replace(/^#/, '') : '',
    hostname: urlParsingNode.hostname,
    port: urlParsingNode.port,
    pathname: (urlParsingNode.pathname.charAt(0) === '/')
      ? urlParsingNode.pathname
      : '/' + urlParsingNode.pathname
  };
}

/**
 * Determine if a URL shares the same origin as the current location
 *
 * @param {String} requestUrl The URL to test
 * @returns {boolean} True if URL shares the same origin, otherwise false
 */
module.exports = function urlIsSameOrigin(requestUrl) {
  var parsed = (utils.isString(requestUrl)) ? urlResolve(requestUrl) : requestUrl;
  return (parsed.protocol === originUrl.protocol &&
        parsed.host === originUrl.host);
};