[3np]

You might think that would be it?

    $ node -e "process.stdout.write('@'.repeat(128 * 1024)); process.stdout.write(''); setTimeout(()=>{ process.exit(0); }, 0);" | wc -c
    131072

Sure. But not so fast! You're still just racing and have no guarantees. Increase the pressure and it snaps back:

    $ node -e "process.stdout.write('@'.repeat(1280 * 1024)); process.stdout.write(''); setTimeout(()=>{ process.exit(0); }, 0);" | wc -c
    65536

Meanwhile:

    $ node -e "const { Stream } = require('stream'); s = process.stdout; s.write('@'.repeat(1280 * 1024)); Stream.finished(s, () => { process.exit(0); })" | wc -c
    1310720

[Thorrez]

You're not passing anything into the 2nd parameter of stdout.write()