How do I stop my nodejs server for test purposes?

In case you need to send the command a SIGTERM signal, you need to handle that with the process signal handler:

Note: process does not require a “require”, it’s automatically available.

const express = require('express')
const app = express()
app.get('/', (req, res) => {
  res.send('Hi!')
});
const server = app.listen(3000, () => console.log('Server ready'));
process.on('SIGTERM', () => {
  server.close(() => {
    console.log('Process terminated');
  });
});

What are signals? Signals are a POSIX intercommunication system: a notification sent to a process in order to notify it of an event that occurred.

SIGKILL is the signals that tells a process to immediately terminate, and would ideally act like process.exit().

SIGTERM is the signals that tells a process to gracefully terminate. It is the signal that’s sent from process managers like upstart or supervisord and many others.

You can send this signal from inside the program, in another function:

process.kill(process.pid, 'SIGTERM')

Or from another Node.js running program, or any other app running in your system that knows the PID of the process you want to terminate.