The Tor Browser / file revision

 // Copyright 2012 Google Inc.  All rights reserved.

 // This code is governed by the BSD license found in the LICENSE file.

 /**

  * @description Tests that Intl.Collator has a supportedLocalesOf

  * property, and it works as planned.

  */

 var defaultLocale = new Intl.Collator().resolvedOptions().locale;

 var notSupported = 'zxx'; // "no linguistic content"

 var requestedLocales = [defaultLocale, notSupported];

 var supportedLocales;

 if (!Intl.Collator.hasOwnProperty('supportedLocalesOf')) {

     $ERROR("Intl.Collator doesn't have a supportedLocalesOf property.");

 }

 supportedLocales = Intl.Collator.supportedLocalesOf(requestedLocales);

 if (supportedLocales.length !== 1) {

     $ERROR('The length of supported locales list is not 1.');

 }

 if (supportedLocales[0] !== defaultLocale) {

     $ERROR('The default locale is not returned in the supported list.');

 }