express.js

/*===================================
|| 
|| NodeJS Server with Express Framework
|| 
===================================*/
/*---------------------------
| Environment Vars
---------------------------*/
require('dotenv').config();

/*---------------------------
| Resources
---------------------------*/
const path = require('path');
const express = require('express');
const cookieParser = require('cookie-parser');
const session = require('express-session');

/*---------------------------
| Mongoose
---------------------------*/
const mongoose = require('mongoose');
mongoose.promise = global.Promise;
const mongoConn = process.env.MONGO_DB_CONN;
/* Connecting to Mongo ---------------------------*/
if (mongoConn) {
    mongoose
        .connect(mongoConn,  { useNewUrlParser: true, useUnifiedTopology: true, useFindAndModify: false })
        .then((res) => {
            console.log('Mongo: Connection made.');
        })
        .catch((err) => {
            console.log(`Mongoose Connection Error: ${err}`);
        });
} else {
    console.log('Missing MONGO_DB_CONN env var for Mongo connection');
}

/*---------------------------
| Express
---------------------------*/
/* Initialize ---------------------------*/
const app = express();

/* JSON support for request response ---------------------------*/
app.use(express.json());

/* Server Session support user access. ---------------------------*/
// initialize cookie-parser to allow us access the cookies stored in the browser. 
app.use(cookieParser());
app.use(session({ 
    secret: "Secret Unique Value",
    resave: false,
    saveUninitialized: true,
}));

/* Serve the static files from the React app ---------------------------*/
app.use(express.static(path.join(__dirname, 'build')));

/*---------------------------
| !IMPORTANT :: Should not be done in Production
| Bypassing CORS so Node Express can be on NODE_PORT 5000 and react can be on 3000
---------------------------*/
if (process.env.NODE_ENV === 'local') {
    console.log('Bypassing CORS for Local Development.');
    app.use((request, response, next) => {
        response.header("Access-Control-Allow-Origin", "*");
        response.header("Access-Control-Allow-Headers", "Content-Type");
        next();
    });
}

/*---------------------------
| Route Collections
---------------------------*/
const routes = require('./express-routes/index.js');
app.use('/api/auctions', routes.auctions);
app.use('/api/users', routes.users);
app.use('/api/bidSubmission', routes.bidSubmission);

// Catchall for requests that do not match our routing
app.get('*', (req, res) => {
    res.sendFile(path.join(__dirname, 'build', 'index.html'));
});

/*---------------------------
| Port Management
---------------------------*/
const HEROKU_PORT = process.env.PORT;
const EXPRESS_PORT = process.env.EXPRESS_PORT;
const PORT = (EXPRESS_PORT) ? EXPRESS_PORT : HEROKU_PORT;
const FINAL_PORT = (PORT) ? PORT : 5000; // In case none are provided fall back to 5000

/*---------------------------
| Start the Server
---------------------------*/
app.listen(FINAL_PORT, () => {
    console.log('Express Server is up and running. Currently listening on port: ' + FINAL_PORT ); 
});

process.on('exit', function () {
    mongoose.connection.close().then((res) => {
        console.log('Mongo: Connection Closed.', res);
    });

    process.emit('cleanup');
});