detectasync

detectasync.js

Iterate over an array asynchronously, returning the first item the passes the async test (for native await/async/Promise)

Installation:

npm install --save detectasync

Usage example:

 
const detectAsync = require('detectasync');
const FsStat = require('util').promisify(require('fs').stat);
 
await detectAsync(files, async function (file, index) {
    
    return (await FsStat(file)).isFile;
    
});
 
 

detectAsync will hold by default 1 one concurrent promises, instead of creating possibly 10,000s of promises ahead of time.
You can control how many promises will be created concurrently, by passing an extra argument or by setting the default.

 
detectAsync.max = 15; // Set default max concurrent promises to 15
 
await detectAsync(files, async function (file, index) {
    
    return (await FsStat(file)).isFile;
    
}, 20 /* 20 concurrent promises */);
 
 
But if you care about the order in the array, to return the very first item in the array the passes the test - keep concurrency to 1.  
(This still runs your code asynchronously).
 

Notes

This library assumes that you use an up-to-date runtime that has a native Promise implementation.
This includes node.js >= v4, Chrome >= v32, and most other browsers (including Edge, excluding IE).

It should be used in conjuction with async/await as demonstrated in the example. As Promises themselves are still creating a bit of spaghetti code, and async/await were introduced to provide a more streamlined and less-noise async code handling.

Contributing

If you have anything to contribute, or functionality that you lack - you are more than welcome to participate in this! If anyone wishes to contribute unit tests - that also would be great :-)

Me

• Hi! I am Daniel Cohen Gindi. Or in short- Daniel.
• [e-mail] is my email address.
• That's all you need to know.

Help

If you want to buy me a beer, you are very welcome to Thanks :-)

License

All the code here is under MIT license. Which means you could do virtually anything with the code. I will appreciate it very much if you keep an attribution where appropriate.

The MIT License (MIT)

Copyright (c) 2013 Daniel Cohen Gindi ([e-mail])

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.