输入下面代码的reactnative的Jest单元测试代码：import React Component from react;import StyleSheet View Text from react-native;import scaleSize from utilslayout; export default class Timer extends Component co

import React from 'react'; import { render, unmountComponentAtNode } from 'react-dom'; import Timer from './Timer';

describe('Timer Component', () => { let container = null;

beforeEach(() => { // Set up a DOM element as a render target container = document.createElement('div'); document.body.appendChild(container); });

afterEach(() => { // Clean up on exiting unmountComponentAtNode(container); container.remove(); });

it('renders without crashing', () => { render(, container); });

it('renders correct timer values', () => { const leftTime = 3600; // 1 hour render(, container); const timerElement = container.querySelector('.timer-box'); expect(timerElement.textContent).toContain('00:59:59'); }); });