express.js launches stuffs and responses if the process is still running

express-server.js

const express = require('express');
const {
  exec,
} = require('child_process');

const app = express();
const port = 7000;

let isRunning = false;

app.get('/', (req, res) => {
  // Response
  res.json({
    isRunning,
  });
});

app.get('/start', (req, res) => {
  if (isRunning) {
    res.json({
      message: 'it is running...',
    });
    return;
  }

  const child = exec('bash process.sh', (err) => {
    if (err) {
      isRunning = false;
    }
  });

  isRunning = true;

  child.on('close', () => {
    isRunning = false;
  });

  child.on('exit', () => {
    isRunning = false;
  });

  // Response
  res.json({
    message: 'starting...',
  });
});

app.listen(port, () => {
  // eslint-disable-next-line no-console
  console.log(`launcher app listening on port ${port}`);
});

process.sh

echo "working..."
sleep 30
echo "bye"