app.ts

import express from "express";
const logger = require('morgan');
const products = require('./routes/products') ;
const users = require('./routes/users');
const mongoose = require('./config/database'); //database configuration
const jwt = require('jsonwebtoken');
const app = express();
const serverless = require('serverless-http')


app.set('secretKey', 'nodeRestApi'); // jwt secret token

// connection to mongodb
mongoose.connection.on('error', console.error.bind(console, 'MongoDB connection error:'));

app.use(logger('dev'));
app.use(express.urlencoded({extended: false}));

app.get('/', function(req, res){
res.json({"Welcome to the Product Inventory" : "Register/Login to Access!"});
});

// public route
app.use('/users', users);

// private route
app.use('/products', validateUser, products);

// avoiding 404 on icon showing by caching No Content status
app.get('/favicon.ico', function(req, res) {
    res.sendStatus(204);
});

function validateUser(req, res, next) {
  jwt.verify(req.headers['x-access-token'], req.app.get('secretKey'), function(err, decoded) {
    if (err) {
      res.json({status:"error", message: err.message, data:null});
    }else{
      // add user id to request
      req.body.userId = decoded.id;
      next();
    }
  });
  
}


// express doesn't consider not found 404 as an error so we need to handle 404 it explicitly
// handle 404 error
app.use(function(req, res, next) {
	let err = new Error('Not Found');
    res.status(404);
    next(err);
});

// handle errors
app.use(function(err, req, res, next) {
	console.log(err);
	
  if(err.status === 404)
  	res.status(404).json({message: "Not found"});
  else	
    res.status(500).json({message: "Something looks wrong :( !!!"});

});

app.listen(3000, function(){
	console.log('Node server listening on port 3000');
});

// wrap express app instance with serverless http function
module.exports.handler = serverless(app)