Run a load test on a given URL

load-test.js

const http = require('http')

let getData = (rand = 1) => {

  return new Promise((resolve, reject) => {

    try {

      let url = 'http://localhost:3000/db/products.count?v=' + rand

      var start = new Date();

      http.get(url, (res) => {

        let responseTime = new Date() - start;

        let body = '';

        res.on('data', (chunk) => { body += chunk })

        res.on('end', () => {
          resolve({ data : body, elapsedTime : responseTime })
        })

      }).on('error', (e) => { return reject(e + '') })

    } catch (e) {
      return reject(e + '')
    }
  })
}

let times = []

setInterval(() => {
  let rand = Math.floor(Math.random() * 1000)

  getData(rand)
    .then((response) => {

    times.push(response.elapsedTime)

    let sum = times.reduce(function(a, b) { return a + b; })
    let avg = Number(sum / times.length)

    console.log(response.data + ' | avg reponse time: ' + avg.toLocaleString("en-US", {
        style : "decimal",
        minimumFractionDigits : 3,
        maximumFractionDigits : 3
      }))
    })
    .catch((e) => {
      console.error(e + '')
    })

}, 30)