function test() { waitForExplicitFinish(); var tab = BrowserTestUtils.addTab(gBrowser); tab.addEventListener( "TabClose", function() { ok( tab.linkedBrowser, "linkedBrowser should still exist during the TabClose event" ); executeSoon(function() { ok( !tab.linkedBrowser, "linkedBrowser should be gone after the TabClose event" ); finish(); }); }, { once: true } ); gBrowser.removeTab(tab); }