index.js

const { Worker } = require('worker_threads');
const path = require('path');

const worker1 = new Worker(path.resolve('./worker.js'), { workerData: { base: 1 } });

const worker2 = new Worker(path.resolve('./worker.js'), { workerData: { base: 10 } });

worker1.on('message', (message) => {
  console.log(`worker1 message: ${message}`);
});

worker2.on('message', (message) => {
  console.log(`worker2 message: ${message}`);
});