multiple threads from node stress testing the cpu

nodestress.js

const shell = require('shelljs');

const nexec = cmd => new Promise((resolve, reject) => {
        shell.exec(cmd, (code, stdout, stderr) => {
                if(stderr) reject(stderr);
                if(code) reject(new Error('exit code'));
                if(stdout) resolve(stdout);
                reject(new Error('unexpected behaviour'));
        })
});

Promise.all([
        nexec('stress --cpu 1 --timeout 10; echo "stress 10";'),
        nexec('stress --cpu 1 --timeout 20; echo "stress 20";'),
        nexec('stress --cpu 1 --timeout 30; echo "stress 30";'),
        nexec('stress --cpu 1 --timeout 40; echo "stress 40";'),
        nexec('stress --cpu 1 --timeout 50; echo "stress 50";'),
        nexec('stress --cpu 1 --timeout 60; echo "stress 60";')
])
.then(console.log);