app.js

const express = require('express');
const routes = require('./routes');
const app = express();

const jsonParser = require('body-parser').json;
const logger = require('morgan');
const mongoose = require('mongoose');

mongoose.connect('mongodb://localhost:27017/QA');
const db = mongoose.connection;

db.on('error', err => {
  console.error(`Error while connecting to DB: ${err.message}`);
});
db.once('open', () => {
  console.log('DB connected successfully!');
});

app.use((req, res, next) => {
  res.header('Access-Control-Allow-Origin', '*');
  res.header(
    'Access-Control-Allow-Headers',
    'Origin, X-Requested-With, Content-Type, Accept'
  );
  if (req.method === 'Options') {
    res.header('Access-Control-Allow-Methods', 'PUT, POST, DELETE');
    return res.status(200).json({});
  }
});
app.use(logger('dev'));
app.use(jsonParser());
app.use('/questions', routes);
app.use((req, res, next) => {
  const err = new Error('Not Found');
  err.status = 404;
  next(err);
});
app.use((err, req, res, next) => {
  res.status(err.status || 500);
  res.json({
    error: {
      message: err.message
    }
  });
});

const port = process.env.port || 3000;

app.listen(port, () => {
  console.log(`Web server listening on: ${port}`);
});