Puppeteer 2 Network throttling 网络节流,切换不同的网络环境

Posted on 六 09 十月 2021 in Puppeteer

参考

网络节流

Chrome 浏览器 DevTools有个功能是网络节流，非常有用。模拟不同的网络环境，预设了Fast 3G，Slow 3G，offline离线也可以自己设定，下载速率，上传速率，延迟时间

Puppeteer支持

let NETWORK_PRESETS = {
  'GPRS': {
    'offline': false,
    'downloadThroughput': 50 * 1024 / 8,
    'uploadThroughput': 20 * 1024 / 8,
    'latency': 500
  },
  'Regular2G': {
    'offline': false,
    'downloadThroughput': 250 * 1024 / 8,
    'uploadThroughput': 50 * 1024 / 8,
    'latency': 300
  },
  'Good2G': {
    'offline': false,
    'downloadThroughput': 450 * 1024 / 8,
    'uploadThroughput': 150 * 1024 / 8,
    'latency': 150
  },
  'Regular3G': {
    'offline': false,
    'downloadThroughput': 750 * 1024 / 8,
    'uploadThroughput': 250 * 1024 / 8,
    'latency': 100
  },
  'Good3G': {
    'offline': false,
    'downloadThroughput': 1.5 * 1024 * 1024 / 8,
    'uploadThroughput': 750 * 1024 / 8,
    'latency': 40
  },
  'Regular4G': {
    'offline': false,
    'downloadThroughput': 4 * 1024 * 1024 / 8,
    'uploadThroughput': 3 * 1024 * 1024 / 8,
    'latency': 20
  },
  'DSL': {
    'offline': false,
    'downloadThroughput': 2 * 1024 * 1024 / 8,
    'uploadThroughput': 1 * 1024 * 1024 / 8,
    'latency': 5
  },
  'WiFi': {
    'offline': false,
    'downloadThroughput': 30 * 1024 * 1024 / 8,
    'uploadThroughput': 15 * 1024 * 1024 / 8,
    'latency': 2
  }
}

const puppeteer = require('puppeteer')

puppeteer.launch().then(async browser => {
  // Create a new tab
  const page = await browser.newPage()

  // Connect to Chrome DevTools
  const client = await page.target().createCDPSession()

  // Set throttling property
  await client.send('Network.emulateNetworkConditions', {
    'offline': false,
    'downloadThroughput': 200 * 1024 / 8,
    'uploadThroughput': 200 * 1024 / 8,
    'latency': 20
  })
  //或者
   await client.send('Network.emulateNetworkConditions',NETWORK_PRESETS['Good3G'])

  // Navigate and take a screenshot
  await page.goto('https://fdalvi.github.io')
  await page.screenshot({path: 'screenshot.png'})
  await browser.close()
})