Getting undefined type on example from web page.

[pkellner]

When I create a simple node project and basically run with just ts-node runfile.ts

I get this error:

/Users/peterkellner/repos/gmail-to-icloud/process-mail-queue/node_modules/imap/lib/Connection.js:227
    var type = self._curReq.type;
                            ^
TypeError: Cannot read properties of undefined (reading 'type')

My example is just this which is exactly what is on the home page:

import Imap from "imap";
import {inspect} from "node:util";

const imap = new Imap({
  user: "xxx",
  password: "xxx",
  host: "imap.gmail.com",
  port: 993,
  tls: true,
  tlsOptions: {rejectUnauthorized: false},
});

function openInbox(cb) {
  imap.openBox("INBOX", true, cb);
}

imap.once("ready", function () {
  openInbox(function (err) {
    if (err) throw err;
    const f = imap.seq.fetch("1:3", {
      bodies: "HEADER.FIELDS (FROM TO SUBJECT DATE)",
      struct: true,
    });
    f.on("message", function (msg, seqno) {
      console.log("Message #%d", seqno);
      const prefix = "(#" + seqno + ") ";
      msg.on("body", function (stream) {
        let buffer = "";
        stream.on("data", function (chunk) {
          buffer += chunk.toString("utf8");
        });
        stream.once("end", function () {
          console.log(prefix + "Parsed header: %s", inspect(Imap.parseHeader(buffer)));
        });
      });
      msg.once("attributes", function (attrs) {
        console.log(prefix + "Attributes: %s", inspect(attrs, false, 8));
      });
      msg.once("end", function () {
        console.log(prefix + "Finished");
      });
    });
    f.once("error", function (err) {
      console.log("Fetch error: " + err);
    });
    f.once("end", function () {
      console.log("Done fetching all messages!");
      imap.end();
    });
  });
});

imap.once("error", function (err) {
  console.log(err);
});

imap.once("end", function () {
  console.log("Connection ended");
});

imap.connect();

[arnt]

Hi,

Your code isn't complete so I couldn't reproduce it, but when I read it carefully I remembered running across something that seemed like a bug in gmail and that would have this effect.

That bug would cause crashes like you've seen, very rarely. But by coincidence, this PR from last week would make the crashes more common. So I updated the PR and fixed it there.

To explain: IMAP servers generally send responses when clients send commands, and many clients assume this to always be the case. But it isn't quite always. An IMAP response always responds to something, but the something doesn't necessarily have to be a command from that client. (Frankly, I think that this is either a poor design choice in IMAP or painfully underdocumented.)

Node-imap assumed that for many kinds of responses, the cause of the response must be the oldest unfinished command sent by node-imap. I weakened that assumption.

[arnt]

Hi,

I've commented on and closed all of the other old issues reported, but will leave this issue until #15 has been merged. Hope to get around to that soon. Not today — now's the time to cook dinner, not to merge and retest any PRs.

[pkellner]

Appreciate you tracking this.

[arnt]

@mikebevz very kindly gave me Contributor status. I wrote a small script that should provoke the kind of crash you've seen often, and it doesn't break in production when I use #15. So I merged #15 now and will close this bug.

I'll take a look at #12 in a few days. #12 is more complicated (difficult to review and I spotted a bug). After that we'll see about making a new release.