Using Async.Js autoInject method to create complex asynchronous calls

Async.JS is a useful library to manage asynchronous JavaScript calls. It can be used in wide variety of ways to solve many common problems.

The following example shows you on how to use async.autoInject to combine many inter dependent asynchronous functions seamlessly

const async = require('async');

/**
 * adds 3 to a number after 2 seconds
 * @param text
 * @returns {Promise<unknown>}
 */
const add3 = (number = 1) => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve(number + 3)
        }, 2000)
    })
}

/**
 * Multiplies after 2 seconds
 * @param a
 * @param b
 * @returns {Promise<unknown>}
 */
const mulitply = (a,b) => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve(a*b)
        }, 2000)
    })
}

/**
 * A control flow using async.autoInject
 * @type {string}
 */
const timerId = 'asyncAuto'
console.time(timerId);
async.autoInject({
    fivePlus3: async () => add3(5),
    onePlus3: async () => add3(1),
    multiplyTheAboveTwoProps: async (fivePlus3,onePlus3) => mulitply(fivePlus3,onePlus3), // takes the resolved values of the fivePlus3,onePlus3
    add3ToFinal: async (multiplyTheAboveTwoProps) => add3(multiplyTheAboveTwoProps), // takes the resolved value of  multiplyTheAboveTwoProps
    add3TofivePlus3: async (fivePlus3) => add3(fivePlus3) // takes the resolved value of fivePlus3
}).then(r => {
    console.timeEnd(timerId);
    console.log('finished controlled flow', r)
})

Find a working example => RunKit

PS: This is the first time i ever wrote anything