navigator.onLine & online / offline events on window
Response.redirect default status: 302
获取所有加载的资源
entries = performance.getEntriesByType('resource')
// 仅图片
images = entries.filter(_ => _.initiatorType === 'img')
// 图片链接
images.map(_ => _.name)
<script> 或脚本文件的执行<noscript> 包裹