app.js

const createError = require('http-errors'),
    express = require('express'),
    path = require('path'),
    cookieParser = require('cookie-parser'),
    logger = require('morgan'),
    mongoose = require('mongoose'),
    cors = require('cors'),
    routes = require('./routes');

const customResponses = require('./middlewares/customResponses');
const mongoURI = process.env.MONGO_URI;

mongoose.connect(mongoURI, {useNewUrlParser: true}, function(err) {
  if(err != null) console.log('Error:\n' + err);
});

let app = express();
app.disable('etag');

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'pug');

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

app.use('/', routes);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;