Тестирование работы V8 — https://habr.com/ru/post/486162/

createObject.js

module.exports = function(keys) {
  for (let key of keys) this[key] = 42;
}

dynamicTest.js

const createObject = require('./createObject.js');
const getKeys = require('./getKeys.js');
const {performance} = require('perf_hooks');

module.exports = function dynamicTest(length = 1000) {
  for (let i = 0; i < length; i++) {
    const entries = getKeys();

    performance.mark('start');

    const obj = new createObject(entries);

    performance.mark('end');
    performance.measure(`${length}`, 'start', 'end');
  }
};

getKeys.js

const makeid = require('./makeid.js');

module.exports = function getKeys(length = 20) {
  let keys = [];
  for (let i = 0; i < length; i++) {
    keys[i] = makeid();
  }
  return keys;
}

index.js

const {promises} = require('fs');
const path = require('path');
const {fork} = require('child_process');


function getPromise(fork) {
  return new Promise((resolve, reject) => {
    fork.on('exit', code => {
      if (code) {
        reject(code);
      } else {
        resolve();
      }
    });
  });
}


let res = {};


function onData({iterations, time, type}) {
  console.log({type, iterations, time});
  if (!res[iterations]) {
    res[iterations] = {[type]: time};
    return;
  }

  res[iterations][type] = time;
}


async function worker(start, end, step, type) {

  for (let i = start; i <= end; i += step) {
    const child = fork('./test.js');

    child.on('message', onData);

    const promise = getPromise(child);
    child.send({count: i, type});
    await promise;
  }
}


(async () => {
  await worker(100, 10_000, 100, 'dynamic');
  await worker(100, 10_000, 100, 'mixed');
  await worker(100, 10_000, 100, 'static');

  const rows = [];

  for (let i in res) {
    rows.push([i, res[i].static, res[i].mixed, res[i].dynamic].join(','));
  }

  const resPath = path.resolve(__dirname, 'result.csv');
  await promises.writeFile(resPath, rows.join('\n'), {flag: 'w', encoding: 'utf8'});
})();

makeid.js

module.exports = function makeid(length = 20) {
  let result = '';
  var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzЙЦУКЕНГШЩЗХЪЁЭЖДЛОРПАВЫФЯЧСМИТЬБЮйцукенгшщзхъёэждлорпавыфячсмитьбю1234567890';
  var charactersLength = characters.length;
  for (var i = 0; i < length; i++) {
    result += characters.charAt(Math.floor(Math.random() * charactersLength));
  }
  return result;
}

mixedTest.js

const createObject = require('./createObject.js');
const getKeys = require('./getKeys.js');
const {performance} = require('perf_hooks');

module.exports = function mixedTest(length = 1000) {
  const staticKeys = getKeys(10);

  for (let i = 0; i < length; i++) {
    const keys = [...staticKeys, getKeys(10)];

    performance.mark('start');

    const obj = new createObject(keys);

    performance.mark('end');
    performance.measure(`${length}`, 'start', 'end');
  }
};

result-per-iteration.csv

result.csv

staticTest.js

const getKeys = require('./getKeys.js');
const {performance} = require('perf_hooks');
const createObject = require('./createObject.js');

module.exports = function staticTest(length = 1000) {
  const keys = getKeys();
  for (let i = 0; i < length; i++) {
    performance.mark(`start`);

    const obj = new createObject(keys);

    performance.mark(`end`);
    performance.measure(`${length}`, `start`, `end`);
  }
};

test.js

const {PerformanceObserver} = require('perf_hooks');

process.on('message', ({count, type}) => {
  const test =
            type === 'static'
            ? require('./staticTest.js')
            : type === 'mixed'
              ? require('./mixedTest.js') : require('./dynamicTest.js');

  let totalTime = 0;

  const obs = new PerformanceObserver((items) => {
    totalTime += items.getEntries()[0].duration;
  });

  obs.observe({entryTypes: ['measure']});

  test(count);

  process.send({iterations: count, time: totalTime, type});
  process.exit(0);
});