Asynchronous Map Function

asyncmodule.js

/**
 * Asynchronous Map Function via async module
 */
const Async = require('async');

Async.map([1,2,3], double, (err, results) => {
    if(err) console.log(err);
    console.log(results)
} );


async function double(num) {

    if(isNaN(num))
        return await new Error('argument is not a number');
    else
        return await num * 2;
}