Gmail IDLE test

server.es6

require("babel/register");
var Imap = require('imap');

var imap = new Imap({
  user: process.env.USERNAME,
  password: process.env.PASSWORD,
  host: 'imap.gmail.com',
  port: 993,
  tls: true
});
var skipResult = true; // skip the first mail result

var onMessage = (msg, seqno) => {
  var prefix = '(#' + seqno + ')';
  var body = '';
  var attrs;
  msg.on('body', (stream, info) => {
    stream.on('data', chunk => body += chunk);
  });
  msg.once('attributes', a => attrs = a);
  msg.once('end', () => {
    console.log(prefix, 'Finished');
    console.log(prefix, 'Body', body);
    console.log(prefix, 'Attrs', attrs);
    // TODO: Take action on the message
    imap.addFlags(attrs.uid, ['\Seen'], err => {
      if (err) throw err;
    });
  });
};

imap.once('ready', () => {
  imap.on('mail', i => {
    console.log(`New mail: ${i}`);
    if (skipResult) {
      skipResult = false;
      return;
    }
    imap.search(['UNSEEN'], (err, results) => {
      if (err) throw err;
      console.log('search', results.length);
      if (results.length == 0) {
        return;
      }

      imap.fetch(results.slice(-1 * i), {
        bodies: ['TEXT', 'HEADER']
      }).on('message', onMessage);
    });
  });
  imap.openBox('INBOX', false, (err, box) => {
    if (err) throw err;
  });
});

imap.once('error', err => console.log(err));
imap.once('end', () => console.log('Connection ended'));
imap.connect();