cypress/system-tests/projects/firefox-memory/cypress.config.js

const _ = require('lodash')
const { execa } = require('execa')
const util = require('util')
const si = require('systeminformation')

let timings = []
let rss = []
let intervalId

module.exports = {
  'e2e': {
    supportFile: false,
    setupNodeEvents (on, config) {
      on('task', {
        'console' (...args) {
          console.log(...args)

          return null
        },
        'stop:capture:memory' () {
          clearInterval(intervalId)
          console.log('available memory', util.inspect(timings, {
            compact: true,
            breakLength: Infinity,
            maxArrayLength: Infinity,
          }))

          console.log('details of available memory', {
            min: _.min(timings),
            max: _.max(timings),
            average: _.chain(timings).sum().divide(timings.length).value(),
          })

          console.log('firefox rss', util.inspect(rss, {
            compact: true,
            breakLength: Infinity,
            maxArrayLength: Infinity,
          }))

          console.log('details of firefox rss', {
            min: _.min(rss),
            max: _.max(rss),
            average: _.chain(rss).sum().divide(rss.length).value(),
          })

          return null
        },
        'capture:memory' () {
          clearInterval(intervalId)

          timings = []

          intervalId = setInterval(() => {
            execa('free', ['-m'])
            .then(({ stdout }) => {
              console.log(stdout)
              const avail = _
              .chain(stdout)
              .split('\n')
              .nth(1)
              .split(' ')
              .last()
              .toNumber()
              .value()

              console.log(avail)
              timings.push(avail)
            })
          }, 1000)

          return null
        },
        'log:memory' () {
          return si.processes()
          .then(({ list }) => {
            const totalRss = _.chain(list)
            // BLOCKING TODO: need to make this detect firefox that are children of Cypress
            // *only* using parent pid and pid, otherwise it will detect the user's
            // Firefox
            .filter((proc) => {
              return ['firefox', 'firefox-bin'].includes(proc.command)
            })
            .sumBy('memRss')
            .thru((kb) => {
              return Math.round(kb / 1024) // mb
            })
            .value()

            console.log({ totalRss })

            rss.push(totalRss)

            return null
          })
        },
      })

      return config
    },
  },
}