DeprecationWarning: timers.unenroll() is deprecated. Please use clearTimeout instead - node.js

Question

While following this youtube video to learn about node.js
I got this error
$ nodemon index.js
(node:18129) [DEP0096] DeprecationWarning: timers.unenroll() is deprecated. Please use clearTimeout instead.
App server still able to run. However as I am trying to add router to add item as the video, it never go through successfully. However, I would call it half- successfully as I do see the data log in the terminal but never go back to database. as you can see, we can see xxx as name as 40 as price in the terminal after I queried
http://localhost:4000/products/add?name=xxx&price=40
in the browser as in the video around 10:52. (I got it working after hard-coding in the index.js file. Why can't I query it as the video did? ) I am assuming the timers.unenorll() causing this. but i Googled it, all i find is this one, and this one(on https://nodejs.org/en/blog/release/v10.0.0/ page)
but don't know what to do with it. cant' find a solution.please help
$ node -v
v10.0.0
const express = require('express');
const cors = require('cors');
const mysql = require('mysql');
const app = express();
app.use(cors());
const SELECT_ALL_PRODUCT_QUERY = 'SELECT * FROM products';
const connection = mysql.createConnection({
host: 'localhost',
user: 'genius',
password: 'genius',
database: 'react_sql'
});
connection.connect(err => {
if(err) {
return err;
}
});
console.log(connection);
app.get('/',(req, res) => {
res.send('go to /products to see the genius gyms')
});
app.get('/products/add', (req, res) => {
const {name, price} = req.query;
//console.log(name, price);
const INSERT_PRODUCTS_QUERY = `INSERT INTO products(name, price) VALUES('${name}',${price})`;
connection.query(INSERT_PRODUCTS_QUERY,(err, results) => {
if(err) {
return res.send(err)
} else {
return res.send('successfully added product')
}
});
});
app.get('/products', (req, res) => {
connection.query(SELECT_ALL_PRODUCT_QUERY,(err,results) => {
if(err) {
return res.send(err)
}
else {
return res.json({
data: results
})
}
});
});
app.listen(4000,() => {
console.log(`Genius gyms listening on
port 4000`)
});

Answer 1

npm install mysql#2.16.0 --save
Just update the mysql library to latest version.

Answer 2

The offender seems to be the mysql module at this spot in the code where you see a call to Timers.unenroll(sequence):
https://github.com/mysqljs/mysql/blob/61b173cbc3e207c5497c6c45c98a4871c01701f3/lib/protocol/Protocol.js#L325
Protocol.prototype._dequeue = function(sequence) {
Timers.unenroll(sequence);
// No point in advancing the queue, we are dead
if (this._fatalError) {
return;
}
this._queue.shift();
var sequence = this._queue[0];
if (!sequence) {
this.emit('drain');
return;
}
this._parser.resetPacketNumber();
this._startSequence(sequence);
};
From various comments on the node.js Github site, it sounds like the API has been deprecated, but won't be removed any time soon. Hopefully, mysql will switch to a substitute at some point. You could inquire on their Github site if you want to know more. The specific issue has already been filed on the mysql site here: https://github.com/mysqljs/mysql/issues/2003 and the current response is that the mysql module does not yet support node.js 10.x.
That presumably means you could rollback your node version to 8.x if you wanted and the issue would probably be gone or just wait for a mysql version that does directly support nodejs 10.x.