index.js

'use strict';

import dotenv from "dotenv";
import mongoose from "mongoose";
import logger from "./config/logger.js";
import app from "./app.js";
  
dotenv.config();

const CONNECTION_URL = process.env.CONNECTION_URL;
const PORT = process.env.PORT || 3000;

// Exit on error
mongoose.connection.on('error', (err) => {
    logger.error(`MongoDB connection error: ${err}`);
    process.exit(1);
});
  
// Mongoose logs in development environment
if (process.env.NODE_ENV !== 'production') {
    mongoose.set('debug', true);
} 

let server;
mongoose.connect(CONNECTION_URL,{useNewUrlParser: true,useUnifiedTopology: true}).then(()=>{
    logger.info('Connected to MongoDB');
    server = app.listen(PORT, () => {
        logger.info(`Listening to port ${PORT}`);
    });
});

const exitHandler = () => {
    if (server) {
      server.close(() => {
        logger.info('Server closed');
        process.exit(1);
      });
    } else {
      process.exit(1);
    }
  };
 
  const unexpectedErrorHandler = (error) => {
    logger.error(error);
    exitHandler();
  };

  process.on('uncaughtException', unexpectedErrorHandler);
  process.on('unhandledRejection', unexpectedErrorHandler);
  
//   process.on('SIGTERM', () => {
//     logger.info('SIGTERM received');
//     if (server) {
//       server.close();
//     }
//   });