app.js

const createError = require('http-errors');
const express = require('express');
const path = require('path');
const cookieParser = require('cookie-parser');
const logger = require('morgan');

const indexRouter = require('./routes');

module.exports = async function () {
  const app = express();

  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('/', 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');
  });
  return app;
}