add_task(async function() { SpecialPowers.pushPrefEnv({set: [ ["layout.spellcheckDefault", 2], ]}); let prefs = await openPreferencesViaOpenPreferencesAPI("paneGeneral", {leaveOpen: true}); is(prefs.selectedPane, "paneGeneral", "General pane was selected"); let doc = gBrowser.contentDocument; let checkbox = doc.querySelector("#checkSpelling"); is(checkbox.checked, Services.prefs.getIntPref("layout.spellcheckDefault") == 2, "checkbox should represent pref value before clicking on checkbox"); ok(checkbox.checked, "checkbox should be checked before clicking on checkbox"); checkbox.click(); is(checkbox.checked, Services.prefs.getIntPref("layout.spellcheckDefault") == 2, "checkbox should represent pref value after clicking on checkbox"); ok(!checkbox.checked, "checkbox should not be checked after clicking on checkbox"); BrowserTestUtils.removeTab(gBrowser.selectedTab); });