const PAGE = ` abc defg `; add_task(async function () { const url = "data:application/xhtml+xml," + encodeURI(PAGE); await BrowserTestUtils.withNewTab( { gBrowser, url, }, async function (browser) { let popup = await openSelectPopup("click"); let menuitems = popup.querySelectorAll("menuitem"); is(menuitems.length, 2, "Should've properly detected two menu items"); is(menuitems[0].textContent, "abc", "Option text should be correct"); is(menuitems[1].textContent, "defg", "Second text should be correct"); ok( !!popup.querySelector("menucaption"), "Should've created a caption for the optgroup" ); } ); });