server.js

const express = require('express');
const dotenv = require('dotenv');
const mongoose = require('mongoose');
const bodyParser = require('body-parser');
const logging = require('./lib/logging');

const app = express();

/**
 * Load environment variables from .env file
 */
dotenv.config();

/**
 * Connect to MongoDB.
 */
if (process.env.MONGODB_URI) {
  mongoose.Promise = global.Promise;
  mongoose.connect(process.env.MONGODB_URI || process.env.MONGOLAB_URI);
  mongoose.connection.on('error', () => {
    throw new Error(
      'MongoDB Connection Error. Please make sure that MongoDB is running.'
    );
  });
}

// Add the request logger before anything else so that it can
// accurately log requests.
// [START requests]
app.use(logging.requestLogger);
// [END requests]

app.set('port', process.env.PORT || 3001);
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

// Express only serves static assets in production
if (process.env.NODE_ENV === 'production') {
  app.use(express.static('client/build'));
}

// The error handler must be before any other error middleware
app.use(logging.errorLogger);

// catch 404 and forward to error handler
app.use((req, res, next) => {
  const err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handler
// no stacktraces leaked to user unless in development environment
app.use((err, req, res) => {
  res.status(err.status || 500).send({
    message: err.message,
    error: app.get('env') === 'development' ? err : {},
  });
});

app.listen(app.get('port'), () => {
  console.log(`Find the server at: http://localhost:${app.get('port')}/`); // eslint-disable-line no-console
});