Why are my callbacks not firing with async queue? - node.js

Question

I am using async queue to process a huge amount of data. The queue works great until I try to perform an update in the database with MongoDB findOneAndUpdate method.
I first establish the queue, and start pushing objects to it from a Node Stream:
//Create queue to process all items
let q = async.queue(processLink, 2);
// Create Node Stream
let createStream = function () {
let stream = fs.createReadStream(LinkData, {encoding: 'utf8'});
let parser = JSONStream.parse('RECDATA.*');
return stream.pipe(parser);
};
//Listen to 'data' event on stream and add object to queue
createStream().on('data', function(link){
q.push(link)
});
Here is my task function, 'processLink'. It is here, that I am having trouble tracking down the problem. Whenever the findOneAndUpdate callback is fired, it enters one of the conditional blocks, and I am getting the message logged out to the console, but when I call the async callback processComplete(), the task does not finish as expected.
As the title suggests, Why are my async callbacks not completing each task?
function processLink(link, processComplete){
if(_.includes(link.URL, 'www.usda.gov') && _.includes(link.URL, '?recid=')){
let url_items = _.split(link.URL, '=',2);
let facilityOrgID = url_items[1];
let update = {$push: {"links": link}};
if(_.isNumber(parseInt(facilityOrgID)) && facilityOrgID.length > 4 ){
Facility.findOneAndUpdate({facilityOrgID: parseInt(facilityOrgID)}, update, (err, result) => {
if(err !== null){
console.log("Error:",err);
return processComplete(err); /** NOT FIRING **/
} else if(err === null && result !== null){
console.log("Link added to:", result.name);
return processComplete(); /** NOT FIRING **/
}else if(err === null && result === null){
console.log('Facility not in database');
processComplete(); /** NOT FIRING **/
}else{
console.log('Something has gone terrible wrong');
}
});
}else{
console.log("Invalid facilityID");
return processComplete();
}
}else{
console.log('Link Discarded:', link.URL);
processComplete(); /** Fires normally **/
}
}

Answer 1

I solved my problem this morning. The callbacks were fine, but rather there was a conditional state of the data I was not aware of, thus it was leading to a state in which the code would never call the processComplete() callback.
If anyone else is finding themselves in a similar bind, and you have tons of data, I would ensure that your data is being reported accurately and there are not some edge cases that were not being processed as expected.