Why can't I use imap to read email messages multiple times? - node.js

Question

I have the following node/typescript process running on Mac.
ip-192-168-1-3:~ reza.razavipour$ uname -a
Darwin ip-192-168-1-3.us-west-2.compute.internal 18.7.0 Darwin Kernel Version 18.7.0: Thu Jan 23 06:52:12 PST 2020; root:xnu-4903.278.25~1/RELEASE_X86_64 x86_64
ip-192-168-1-3:~ reza.razavipour$ node -v
v12.14.0
ip-192-168-1-3:~ reza.razavipour$ npm -v
"imap": "^0.8.19"
"typescript": "^3.9.7",
I have a node server that is supposed to read emails, it is called from a specific route. Nothing fancy.
The following code is in a ts file and it exports one function namely
export const connect = () => {
imap.connect()
}
first time i call this function, all is well, I connect I read the specific email and no issues.
Next time I call the exported function nothing happens.
Is there a clean up that i am not doing or what am I missing?
const Imap = require('imap');
const MailParser = require('mailparser').MailParser;
import { logger } from '../util/logger';
var imap = new Imap({
user: 'user',
password: 'pw',
host: 'host',
port: 32,
tls: true,
tlsOptions: {rejectUnauthorized: false}
}
);
function openInbox(cb) {
imap.openBox('INBOX', false, cb);
}
function processMessage(msg, seq) {
logger.debug('Processing msg #' + seq);
const parser = new MailParser();
parser.on('data', data => {
if (data.type === 'attachment') {
console.log(data.filename);
// data.content.pipe(process.stdout);
data.content.on('end', () => data.release());
}
});
msg.on('body', stream => {
stream.on('data', function(chunk) {
parser.write(chunk.toString('utf8'));
});
});
msg.once('end', () => {
logger.debug('Finished msg #' + seq);
parser.end();
});
}
imap.once('ready', function() {
openInbox((err, box) => {
try {
if (err) {
logger.error(err);
imap.end();
return;
}
imap.search(['ALL', ['SUBJECT', '32']], (err, results) => {
if (err) {
logger.error(err);
imap.end();
return;
}
if (!results || !results.length) {
logger.error('No unread mails');
imap.end();
return;
}
var f = imap.fetch(results, {bodies: ''});
results.forEach(result => {
const f = imap.fetch(result, {bodies: ''});
f.on('message', processMessage);
f.once('error', (err) => {
logger.error('Fetch error: ' + err);
});
f.once('end', () => {
logger.debug('Done fetching all unseen messages.');
imap.end();
});
});
});
} catch (e) {
logger.error(e);
}
});
});
imap.once('error', (err) => {
logger.error(err);
});
imap.once('end', () => {
logger.debug('Connection ended');
});
export const connect = () => {
imap.connect()
}

Answer 1

it turns, at least in my experimentation, once an Imap instance is connected and ended, it can not be used for follow on connection activities.
Only change I made was to create a new Imap object and use it for the next connection.