Async Test

asyncTest.js

const delay = (msg, time) => 
    new Promise((res, rej) => {
        setTimeout(() => res({msg: `${msg} in ${time}ms`, time: time}), time)
    })

const fn1 = (msg = "fn1", time = 1000) => delay(msg, time)
const fn2 = (msg = "fn2", time = 2000) => delay(msg, time)
const fn3 = (msg = "fn3", time = 3000) => delay(msg, time)
const plus = (a = 0, b = 0) => a + b
const times  = {
  1:0,
  2:0,
  3:0
}

const allMessages = (acc, el) => {
    acc += `(${el.msg})`
    return acc 
}


// *************** PROMISE *******************
fn1("Promise 1")
.then(res => {
        console.log('--')
        console.log('--')
        console.log('--')
        times[1] += res.time
        console.log(`Result single promise (${res.msg}) - Total time: ${times[1]}ms`) 
        return fn2("Promise 2")
      })
.then(res => {
        console.log('--')
        console.log('--')
        console.log('--')
        times[1] += res.time
        console.log(`Result single promise (${res.msg}) - Total time: ${times[1]}ms`) 
        return fn3("Promise 3")
      })
.then(res => {
        console.log('--')
        console.log('--')
        console.log('--')
        times[1] += res.time
        console.log(`Result single promise (${res.msg}) - Total time: ${times[1]}ms`) 
        console.log('--')
        console.log('--')
        console.log('--')
      })


// *************** PROMISE ALL *******************
console.time("Run Promise ALL in")   
Promise.all([fn1(), fn2(), fn3()])
.then(res => {
  console.log('--')
  console.log('--')
  console.log('--')
  console.log(`Promise All *** ${res.reduce(allMessages, '')} ***`)
  console.timeEnd("Run Promise ALL in")
})


// *************** PROMISE RACE *******************
console.time("Run Promise RACE in") 
Promise.race([fn1(), fn2(), fn3()])
.then(res => {
  console.log('--')
  console.log('--')
  console.log('--')
  console.log(`Promise RACE *** ${res.msg} ***`)
  console.timeEnd("Run Promise RACE in")
})


// *************** ASYNC / AWAIT *******************
const asyncMethod = async () => {
  const p1 = await fn1()
  const p2 = await fn2()
  const p3 = await fn3()
  
  console.log({p1, p2, p3}) // prints the result of the promises in a synchronous process
  return [p1, p2, p3] // return all promises with pending status
}

console.time("Run Promise Async / Await in")
asyncMethod().then(res => {
  console.log('--')
  console.log('--')
  console.log('--')
  console.log(`Result async ${res.reduce(allMessages, '')}`)
  console.timeEnd("Run Promise Async / Await in")
})