app.js

var express = require('express');
var mongoose = require('mongoose');
var bodyParser = require('body-parser');
var db;
if (process.env.ENV == 'PROD') {
 db = mongoose.createConnection('mongodb://localhost/prod_db');
} else {
 db = mongoose.createConnection('mongodb://localhost/dev_db');
}
db.on('error', function(err) {
 if (err) {
  console.log('error connecting to db, ' + err);
 }
});
db.once('open', function callback() {
 console.log('db opened');
});
var bookCollection = require('./models/bookModel');
var app = express();
var port = process.env.PORT || 8000;
app.use(bodyParser.urlencoded({
 extended: true
}));
app.use(bodyParser.json());
var bookRouter = require('./routes/bookRoutes')(bookCollection);
app.use('/api/books', bookRouter);
app.get('/', function(req, res) {
 res.send('THE API IS WORKING FINE!');
});
app.listen(port, function() {
 console.log('Starting server on port : ' + port);
});

module.exports = app;