js callback vs promise vs async/await

cb-vs-promise-vs-asyncawait.ts

function performLongTask(cb: (err:any, res: any) => any) {
    const returnValue = 42;
    setTimeout(() => cb(null, returnValue), 3000)
}

performLongTask((err, res) => {
    if (err) throw new Error('we got an error');
    console.log("callback:", res)
})

function performLongTaskPromise() {
    return new Promise(function(resolve, reject) {
        performLongTask((err, res) => {
            if (err) reject(err)
            resolve(res)
        })
    })
}

performLongTaskPromise().then(res => {console.log("Promise.then:", res)}, err => {throw new Error('we got an error')});

(async () => {
    let res;
    try {
        res = await performLongTaskPromise()
    } catch (err) {
        throw new Error('we got an error');
    }
    console.log("async/await:", res)
})()

// this prints all 3 results, after 3s:
// "callback:",  42 
// "Promise.then:",  42 
// "async/await:",  42

https://javascript.info/promise-basics
https://v8.dev/blog/fast-async
https://jakearchibald.com/2015/tasks-microtasks-queues-and-schedules/

TODO: read and understand https://nodejs.org/en/docs/guides/event-loop-timers-and-nexttick/