childProcess.stdout.on("data") does not get progress output from npm install

[Roaders]

• Node.js Version: 12.18.0
• OS: Windows 10
• Scope (install, code, runtime, meta, other?): runtime
• Module (and version) (if relevant): child_process

const installProcess = exec(`npm install lodash`);

installProcess.stdout.on('data', data => console.log(`stdout:data`, data));

output:

stdout:data + [email protected]
removed 1 package and updated 1 package in 18.399s

stdout:data
86 packages are looking for funding
  run `npm fund` for details

when you do npm install on the command line you get a load of output indicating the progress being made. I want to show this progress but I do not get any events from installProcess.stdout.on('data') other than the output at the end when the install has finished. I have tried as many different events as I can find (including readable and this.read()) and I have tried spawn rather than exec but still don't seem to get any progress updates.

I assume that npm is logging these events to a different stream but I don't seem to be able to intercept it at all.

Is there a way of listening to these updates?

Many thanks.

[RaisinTen]

How about this?

test.js

const { spawn } = require('child_process');

const installProcess = spawn('npm', ['install', 'lodash'], {
  stdio: 'inherit'
});

installProcess.on('close', (code) => console.log(`exit code: ${ code }`));

❯ node test.js

up to date, audited 1 package in 2s

found 0 vulnerabilities
exit code: 0

[Roaders]

There is no callback arg on spawn so it can't be used with the Promisify util to return a promise.

[RaisinTen]

We can write a wrapper around spawn to accept a callback. Here is a very basic implementation of what I mean:

const util = require('util');
const { spawn } = require('child_process');

function mySpawn(command, args, options, cb) {
  const child = spawn(command, args, options);
  child.on('close', (exitCode) => { cb(null, exitCode) });
  return child;
}

const mySpawnPromisified = util.promisify(mySpawn);

mySpawnPromisified(
  'npm',
  ['i', 'lodash'],
  { stdio: 'inherit' }
).then(function(exitCode) {
    console.log(`Exited with: ${ exitCode }`);
  });

[github-actions[bot]]

It seems there has been no activity on this issue for a while, and it is being closed in 30 days. If you believe this issue should remain open, please leave a comment. If you need further assistance or have questions, you can also search for similar issues on Stack Overflow. Make sure to look at the README file for the most updated links.

[github-actions[bot]]

It seems there has been no activity on this issue for a while, and it is being closed. If you believe this issue should remain open, please leave a comment. If you need further assistance or have questions, you can also search for similar issues on Stack Overflow. Make sure to look at the README file for the most updated links.