Why uncaughtException handler not working globally?

I'm developing a Express + PostgreSQL app and I want to implement a global error handler system. Now I want to caught all uncaught exceptions from my entire project. Server is running with nodemon.

A code like this console.log(x) should give a custom error that I created because x is not defined;

I'm putting process.on('uncaughtException', () => {}) in my server.js file, located in root directory and inserting error with console.log(x) in app.js that is also in root directory folder.

Here is my server.js code:

import './src/config/dotenv.js';
import app from './app.js';

process.on('uncaughtException', (err) => {
  console.log(err.name, err.message);
  console.log('UNCAUGHT EXCEPTION! 💥 Shutting down...');
  process.exit(1);
});

const port = 3000;

const server = app.listen(port, () => {
  console.log(`Server running on port ${port}...`);
});

process.on('unhandledRejection', (err) => {
  console.log(err.name, err.message);
  console.log('UNHANDLED REJECTION! 💥 Shutting down...');
  server.close(() => {
    process.exit(1);
  });
});

This is what I tried:

1. I already tried to put uncaughtException handler on top, before all imports, but that's not working;
2. And problem I also not in nodemon;
3. I don't have any others uncaughtExceptions handlers in other files;
4. console.log(x) error is not located in asynchronous code, I understand that this handler only caught synchronous code;

Here is the solution. Before that I was only using CommonJS syntax, but this project started with ES6 syntax. There are some difference, ES6 is not as global as CommonJS.

Solution: I removed uncaught exception from server.js file and created a separate uncaughtException.js file and just imported in my server.js like this:

uncaughtException.js

process.on('uncaughtException', (err) => {
  console.log(err.name, err.message);
  console.log('UNCAUGHT EXCEPTION! 💥 Shutting down...');
  process.exit(1);
});

server.js

import './src/utils/uncaughtException.js';

And that's it! Do this when some variables are not global when using ES6.