Lighthouse Throttle run

throttle_run_time.js

/*Need to change fetch different value from url array manually.
  Because performance degrades with continous run.
  */
//Tested for regular 3G
const fs = require('fs');
const lighthouse = require('lighthouse');
const chromeLauncher = require('chrome-launcher');

const url = ["https://www.amazon.in/", "https://twitter.com/", "https://www.snapdeal.com/", "https://abc.com/", "https://www.ticket.at/de/home" ];
const DEVTOOLS_RTT_ADJUSTMENT_FACTOR = 3.75;
const DEVTOOLS_THROUGHPUT_ADJUSTMENT_FACTOR = 0.9;
(async () => {
  element = url[3]
  const chrome = await chromeLauncher.launch();
  const options = {logLevel: 'silent', output: 'json', onlyCategories: ['performance'], port: chrome.port};
  const mobileRegular3g = {
    extends: 'lighthouse:default',
    settings: {
      maxWaitForFcp: 15 * 1000,
      maxWaitForLoad: 35 * 1000,
      emulatedFormFactor: 'desktop',
      throttling:  {
        rttMs: 300,
        throughputKbps: 700,
        requestLatencyMs: 300 * DEVTOOLS_RTT_ADJUSTMENT_FACTOR,
        downloadThroughputKbps: 700 * DEVTOOLS_THROUGHPUT_ADJUSTMENT_FACTOR,
        uploadThroughputKbps: 700 * DEVTOOLS_THROUGHPUT_ADJUSTMENT_FACTOR,
      }
    }
  };
  const runnerResult = await lighthouse(element, options, mobileRegular3g);

  // `.report` is the HTML report as a string
  const report = runnerResult.report;
  const file_name = "throttle_"+element.split('/')[2]+".json"
  fs.writeFileSync(file_name, report);

  console.log("URL: "+element+ ", " +runnerResult.lhr.categories.performance.score * 100, "runtime: "+ JSON.parse(report).timing.total);

  await chrome.kill();
})();