app.js

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var logger = require('morgan');
var session = require('express-session');
var indexRouter = require('./routes/index');

var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

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

//activate express-session
app.use( session({secret: 'SECRET_KEY',
resave: false,  // Set the resave option
saveUninitialized: true }))

app.use('/', indexRouter);


// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
  res.status(404).send('Sorry, page not found');
});

// 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 if there's any error occurs
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;