A node.js starter script that uses websockets to facilitate communication between a web client and a chat bot living at pandorabots.com

node-bot-starter-app.js

const server          = require('http').createServer(),
      express         = require('express'),
      jade            = require('jade'),
      debug           = require('debug')('loanbot:server'),
      fs              = require('fs'),
      path            = require('path')
      WebSocketServer = require('ws').Server,
      pandoraBot      = require('pb-node'),
      app             = express(),
      wss             = new WebSocketServer({ server }),
      port            = normalizePort(process.env.PORT || '4090'),
      options         = {
        url: 'https://aiaas.pandorabots.com',
        app_id: 'pandorabots app id',
        user_key: 'pandorabots user key',
        botname: 'pandorabots bot name'
      }
      bot             = new pandoraBot(options);

app.use(express.static(path.join(__dirname, '/public')));
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use( (req, res) => { res.render('home/index'); });

wss.on('connection', (ws) => {

  ws.on('message', (input) => {

    bot.talk({ input }, (err, res) => {
      if (err)
        ws.send('Sorry I\'m having trouble collecting my thoughts');
      if (res.responses)
        ws.send(res.responses[0]);
    });

    fs.appendFile('input.txt', `${ input }\r\n`, (err) => {
      if (err)
        console.log(err);
    });

  });
});

server.listen(port);
server.on('request', app);
server.on('error', onError);
server.on('listening', onListening);

function normalizePort(val) {
  const port = parseInt(val, 10);
  if (isNaN(port))
    return val;
  if (port >= 0)
    return port;
  return false;
}

function onError(error) {
  if (error.syscall !== 'listen')
    throw error;

  const bind = typeof port === 'string'
    ? `Pipe ${port}`
    : `Port ${port}`;

  // handle specific listen errors with friendly messages
  switch (error.code) {
    case 'EACCES':
      console.error(`${bind} requires elevated privileges`);
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(`${bind} is already in use`);
      process.exit(1);
      break;
    default:
      throw error;
  }
}

function onListening() {
  const addr = server.address();
  const bind = typeof addr === 'string'
    ? `Pipe ${port}`
    : `${port} addr.port`;
  debug(`running on port: ${addr.port}`);
  console.log(`running on port: ${addr.port}`);
}