// Copyright 2014 The Flutter Authors. All rights reserved.// Use of this source code is governed by a BSD-style license that can be// found in the LICENSE file.import'dart:html';import'package:flutter_test/flutter_test.dart';/// Whether the current browser is Firefox.boolgetisFirefox=>window.navigator.userAgent.toLowerCase().contains('firefox');/// Finds elements in the DOM tree rendered by the Flutter Web engine.////// If the browser supports shadow DOM, looks in the shadow root under the/// `<flt-glass-pane>` element. Otherwise, looks under `<flt-glass-pane>`/// without penetrating the shadow DOM. In the latter case, if the application/// creates platform views, this will also find platform view elements.List<Node>findElements(Stringselector){finalElement?glassPane=document.querySelector('flt-glass-pane');if(glassPane==null){fail('Failed to locate <flt-glass-pane>. Possible reasons:\n'' - The application failed to start'' - `findElements` was called before the application started');}finalShadowRoot?shadowRoot=glassPane.shadowRoot;returnshadowRoot!=null?shadowRoot.querySelectorAll(selector):glassPane.querySelectorAll(selector);}