Spawn and kill a bash script from js. Handle signal from bash.

counter.sh

#!/bin/bash

trap 'handle_signal SIGINT' SIGINT
trap 'handle_signal SIGQUIT' SIGQUIT
trap 'handle_signal SIGTERM' SIGTERM
trap 'handle_signal SIGHUP' SIGHUP
trap 'handle_signal SIGKILL' SIGKILL  # we can't handle this

handle_signal() {
    echo "received: $1. Exiting..."
    exit
}

count=0
while true; do
    sleep 1
    count=$(( $count + 1 ))
    echo $count
done

run-script.sh

#!/usr/bin/env node

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

const script = spawn(path.join(__dirname, 'counter.sh'));

// Log the script output
script.stdout.on('data', function(data) {
  console.log(data.toString().trimEnd());
});

setTimeout(function() {
  // script.kill('SIGTERM'); // works
  // script.kill('SIGHUP'); // works
  // script.kill('SIGKILL'); // works but script can't handle it
  script.kill('SIGINT'); // works
}, 3000)

To run this you'll need to:

$ chmod +x counter.sh run-script.js

Example run:

$ ./run-script.js
1
2
received: SIGINT. Exiting...