Function getDefaultBootstrapBaseUrl

src/3p-frame.js:251–266

(parentWindow, opt_srcFileBasename)

 * @return {string}
 */
export function getDefaultBootstrapBaseUrl(parentWindow, opt_srcFileBasename) {
  const srcFileBasename = opt_srcFileBasename || 'frame';
  if (!mode.isProd()) {
    return getDevelopmentBootstrapBaseUrl(parentWindow, srcFileBasename);
  }
  // Ensure same sub-domain is used despite potentially different file.
  parentWindow.__AMP_DEFAULT_BOOTSTRAP_SUBDOMAIN =
    parentWindow.__AMP_DEFAULT_BOOTSTRAP_SUBDOMAIN ||
    getSubDomain(parentWindow);
  return (
    'https://' +
    parentWindow.__AMP_DEFAULT_BOOTSTRAP_SUBDOMAIN +
    `.${urls.thirdPartyFrameHost}/${mode.version()}/` +
    `${srcFileBasename}.html`
  );
}

/**
 * Function to return the development bootstrap base URL