"use strict"; add_task(function* () { let tab1 = gBrowser.addTab("data:text/plain;charset=utf-8,foo"); gBrowser.pinTab(tab1); yield promiseBrowserLoaded(tab1.linkedBrowser); let tab2 = gBrowser.addTab(); gBrowser.pinTab(tab2); is(Array.indexOf(gBrowser.tabs, tab1), 0, "pinned tab 1 is at the first position"); yield promiseRemoveTab(tab1); tab1 = undoCloseTab(); ok(tab1.pinned, "pinned tab 1 has been restored as a pinned tab"); is(Array.indexOf(gBrowser.tabs, tab1), 0, "pinned tab 1 has been restored to the first position"); yield BrowserTestUtils.removeTab(tab1); yield BrowserTestUtils.removeTab(tab2); });