"use strict"; const GUIDS = [ PlacesUtils.bookmarks.rootGuid, ...PlacesUtils.bookmarks.userContentRoots, PlacesUtils.bookmarks.tagsGuid, ]; add_task(async function test_isRootItem() { for (let guid of GUIDS) { Assert.ok( PlacesUtils.isRootItem(guid), `Should correctly identify root item ${guid}` ); } Assert.ok( !PlacesUtils.isRootItem("fakeguid1234"), "Should not identify other items as root." ); });