Function parseUrlWithA

src/url.js:106–174

(anchorEl, url, opt_cache)

 * @restricted
 */
export function parseUrlWithA(anchorEl, url, opt_cache) {
  if (mode.isEsm()) {
    // Doing this causes the <a> to auto-set its own href to the resolved path,
    // which would be the baseUrl for the URL constructor.
    anchorEl.href = '';
    return /** @type {?} */ (new URL(url, anchorEl.href));
  }

  if (opt_cache && opt_cache.has(url)) {
    return opt_cache.get(url);
  }

  anchorEl.href = url;

  // IE11 doesn't provide full URL components when parsing relative URLs.
  // Assigning to itself again does the trick #3449.
  if (!anchorEl.protocol) {
    anchorEl.href = anchorEl.href;
  }

  const info = /** @type {!Location} */ ({
    href: anchorEl.href,
    protocol: anchorEl.protocol,
    host: anchorEl.host,
    hostname: anchorEl.hostname,
    port: anchorEl.port == '0' ? '' : anchorEl.port,
    pathname: anchorEl.pathname,
    search: anchorEl.search,
    hash: anchorEl.hash,
    origin: null, // Set below.
  });

  // Some IE11 specific polyfills.
  // 1) IE11 strips out the leading '/' in the pathname.
  if (info.pathname[0] !== '/') {
    info.pathname = '/' + info.pathname;
  }

  // 2) For URLs with implicit ports, IE11 parses to default ports while
  // other browsers leave the port field empty.
  if (
    (info.protocol == 'http:' && info.port == 80) ||
    (info.protocol == 'https:' && info.port == 443)
  ) {
    info.port = '';
    info.host = info.hostname;
  }

  // For data URI anchorEl.origin is equal to the string 'null' which is not useful.
  // We instead return the actual origin which is the full URL.
  let origin;
  if (anchorEl.origin && anchorEl.origin != 'null') {
    origin = anchorEl.origin;
  } else if (info.protocol == 'data:' || !info.host) {
    origin = info.href;
  } else {
    origin = info.protocol + '//' + info.host;
  }