app.js

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
const passport = require("passport");
const cors = require('cors');
const mongoose = require('mongoose');

require('dotenv').config();

var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
const User = require('./models/user');

var app = express();

const mongoDB_URI = process.env.MONGO_URI;
mongoose.set('strictQuery', false);

main().catch(err =>  console.log(err));
async function main() {
  await mongoose.connect(mongoDB_URI);
}

passport.serializeUser(function(user, done) {
  done(null, user.id);
});
passport.deserializeUser(async function(id, done) {
  try {
    const user = await User.findById(id);
    done(null, user);
  } catch(err) {
    done(err);
  };
});

app.use(passport.initialize());
app.use(express.urlencoded({ extended: false }));

app.use(logger('dev'));
app.use(cors());

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

app.use('/users', usersRouter);
app.use('/', indexRouter);


// 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;