Express App Translated to ES2015

.eslintrc

{
  "parser": "babel-eslint",

  "env": {
  	"node": true,
  	"es6": true
  },

  "rules":{
  	"vars-on-top": 2,
  	"no-undef": 2
  }
}

app.js

"use strict";
import express      from 'express';
import path         from 'path';
import favicon      from 'serve-favicon';
import logger       from 'morgan';
import cookieParser from 'cookie-parser';
import bodyParser   from 'body-parser';

import routes       from './routes/index';
import users        from './routes/users'

//using let
let app = express();

app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);

// using arrow syntax
app.use((req, res, next) => {
  let err = new Error('Not Found');
  err.status = 404;
  next(err);
});

if (app.get('env') === 'development') {
  app.use((err, req, res, next) => {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

app.use((err, req, res, next) => {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});


module.exports = app;

gistfile1.txt

{
  "name": "es6-express",
  "version": "0.0.0",
  "description": "ES6/ES2015 Express Example",
  "repository": "n/a",
  "license": "MIT",
  "author": "Steven",
  "scripts": {
    "lint": "eslint app.js",
    "start": "babel-node ./bin/www",
    "auto-start": "nodemon --exec \"npm run lint && npm start\" --ignore public/js"
  },
  "dependencies": {
    "body-parser": "~1.13.2",
    "cookie-parser": "~1.3.5",
    "debug": "~2.2.0",
    "express": "~4.13.1",
    "jade": "~1.11.0",
    "morgan": "~1.6.1",
    "serve-favicon": "~2.3.0"
  },
  "devDependencies": {
    "babel": "^5.8.21",
    "babel-eslint": "^4.0.10",
    "eslint": "^1.1.0",
    "nodemon": "^1.4.1"
  }
}