例如,模拟一个fetch调用:import fetch from 'jest-fetch-mock';beforeAll(() => { fetch.mockResponseOnce(JSON.stringify 组件库的测试对于复杂的组件库,可以创建一个setupTests.js文件来设置全局的模拟和配置,例如:import '@testing-library/jest-dom';import fetchMock from 'jest-fetch-mock