hacklone / arraync Goto Github PK

Correct me if I'm wrong, but as far as I can tell, there is no proposal for adding async functions to the array prototype, is there? If that's the case as I suspect, calling this library a polyfill is misleading. Also, editing the prototype of built-in types (such as the Array object) is highly discouraged these days as it risks clashes with future standards and other libraries. I suggest you change your library so it uses a new custom array type instead of adding extra methods to the prototype of the native Array. Here's an example using the ES2015 class syntax:

class AsyncArray extends Array {

    constructor(…args) { super(…args); } // Apparently, this super call is necessary for built-in types

    // Your extra async functions
}

This is my code -

'use strict';

const arraync = require('arraync');

function greaterThan3(num){
   return new Promise(function(resolve, reject){
   	setTimeout(function(){
   		resolve(num > 3);
   	}, 1000);
   });
}

var numbers = [1,2,3,4,5];

(async()=>{
   const ans = await numbers.filterAsync(await greaterThan3Async);
   console.log(ans);
})();

I'm trying to filter the array using an async function but this is what I get as output -

[ false, false, false, true, true ]

Also I get this same output when I use mapAsync instead of filterAsync.

How do I get the output -

[4, 5]

When I import the code using import 'arraync' in typescript, it permanently adds all async array function names to any array props resulting in the following when I try to iterate an array using a for...in-loop in js:

var a = [1,2,3]; for(var item in a) console.log(item);

results in:

This causes a lot of problems for me, because accessing elements using the index is always broken. Is there a quick fix for this without searching the whole transpiled code? ;)