• Version: v10.10.0
• Platform: Windows x64

parent.js

require('child_process').spawn('node', ['child.js'], {
  stdio: 'inherit',
});

child.js

const doNothing = () => {};
process.stdin.on('data', doNothing);

require('child_process').spawn('node', ['-v']).on('exit', () => {
  process.stdin.unref();
  console.log('After printing this, the process should exit');
});

Run with node parent.js

Results

Linux: The process terminates by itself
Mac: The process terminates by itself
Windows: The process keeps running until Enter is pressed

This strange behavior seems to break some npm modules.

Other details

Adding process.stdin.removeListener('data', doNothing)
or process.stdin.removeAllListeners('data')
before unref doesn't make any difference.

When enter is pressed, it doesn't trigger data callback, just terminates the process.

Edit

Simplified code:

// parent.js
process.stdin.on('data', () => {});
setTimeout(() => {
  process.stdin.unref();
  console.log('After printing this, the process should exit');
});

Here we don't have a child process. Run with node parent.js

Results on windows

50% of times - the process exits
50% of times - the process keeps running