promisify-child-process

promisify-child-process

seriously like the best async child process library

Based upon child-process-async, but more thorough, because that package doesn't seem very actively maintained.

promisify-child-process provides a drop-in replacement for the original child_process functions, not just duplicate methods that return a Promise. So when you call exec(...) we still return a ChildProcess instance, just with .then() and .catch() added to make it promise-friendly.

Install and Set-up

npm install --save promisify-child-process

If you are using a old version of Node without build-in Promises or Object.create, you will need to use polyfills.

Usage

// OLD:
const { exec, spawn, fork, execFile } = require('child_process');
// NEW:
const { exec, spawn, fork, execFile } = require('promisify-child-process');

If for any reason you need to wrap a ChildProcess you didn't create, you can use the exported promisifyChildProcess function:

const {promisifyChildProcess} = require('promisify-child-process');

async function() {
  const { stdout, stderr } = await promisifyChildProcess(
    some3rdPartyFunctionThatReturnsChildProcess()
  )
}

Examples

exec()

async function() {
  const { stdout, stderr } = await exec('ls -al');
  // OR:
  const child = exec('ls -al', {});
  // do whatever you want with `child` here - it's a ChildProcess instance just
  // with promise-friendly `.then()` & `.catch()` functions added to it!
  child.stdin.write(...);
  child.stdout.pipe(...);
  child.stderr.on('data', (data) => ...);
  const { stdout, stderr } = await child;
}

spawn()

async function() {
  const { stdout, stderr, exitCode } = await spawn('ls', [ '-al' ]);
  // OR:
  const child = spawn('ls', [ '-al' ], {});
  // do whatever you want with `child` here - it's a ChildProcess instance just
  // with promise-friendly `.then()` & `.catch()` functions added to it!
  child.stdin.write(...);
  child.stdout.pipe(...);
  child.stderr.on('data', (data) => ...);
  const { stdout, stderr, exitCode } = await child;
}