Performance

devconsole.js

// Modify the destination object and copy paste this script in the chrome dev tools.
// Very useful to track performance for API requests.

function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}
async function performanceURL(url, sampleSize, sleepMs = 1000) {
  const performanceList = [];
  for (let i = 0; i < sampleSize; i++) {
    const t0 = performance.now();
    await fetch(url);
    const t1 = performance.now();
    performanceList.push(t1 - t0);
    console.log(`Request ${i}: ${t1 - t0}ms`);
    await sleep(sleepMs);
  }
  return performanceList;
}

function mean(arr) {
  return arr.reduce((a, b) => a + b) / arr.length;
}

async function calculatePerformance(destinations, sampleSize = 10) {
  const results = {};
  for (let [key, url] of Object.entries(destinations)) {
    console.log(`Calculating performance for ${key}`);
    const performanceList = await performanceURL(url, sampleSize);
    results[key] = {
      performanceList,
      mean: mean(performanceList),
    };
    console.log(`## Mean for ${key}: ${results[key].mean}ms`);
  }
  window.results = results;
  console.log(results);
  return results;
}

calculatePerformance(
  // MODIFY THE DESTINATION OBJECT
  {
    siteOne: "/1",
    sitesTwo: "/2",
  },
  3
);