The Tor Browser / file revision

 /* Any copyright is dedicated to the Public Domain.

    http://creativecommons.org/publicdomain/zero/1.0/ */

 function test() {

   let newTab;

   let onLoad = function (win) {

     registerCleanupFunction(function () win.close());

     newTab = win.gBrowser.addTab();

     let popup = win.document.getElementById("context_tabViewMenuPopup");

     win.TabView.updateContextMenu(newTab, popup);

   };

   let onShow = function (win) {

     let cw = win.TabView.getContentWindow();

     is(cw.GroupItems.groupItems.length, 1, "Has only one group");

     let groupItem = cw.GroupItems.groupItems[0];

     let tabItems = groupItem.getChildren();

     let tab = tabItems[tabItems.length - 1].tab;

     is(tab, newTab, "The new tab exists in the group");

     finish();

   };

   waitForExplicitFinish();

   newWindowWithTabView(onShow, onLoad);

 }