Simple Node Child Process Broadcasting

child.js

process.on('message', (message) => {
  console.log('child received:', message)
  process.send(message) // echo the message back to parent
})

parent.js

const { fork } = require('child_process')

const children = new Array(5)

for (let i = 4; i > -1; i--) {
  children[i] = fork('./child.js')
  children[i].sendMessage = (message) => {
    return new Promise((resolve, reject) => {
      children[i].messageListener = (message) => {
        children[i].removeListener('message', children[i].messageListener)
        resolve(message)
      }
      children[i].on('message', children[i].messageListener)
      children[i].send(message)
    })
  }
}

Promise.all(children.map((child, i) => child.sendMessage(i)))
  .then((results) => console.log('results:', results)) // results: [ 0, 1, 2, 3, 4 ]