Miss any of our Open RFC calls?Watch the recordings here! »

ensure-async

1.0.0 • Public • Published

ensure-async

Last version Dependency status Dev Dependencies Status NPM Status Gratipay

Wrap an async function and ensure it calls its callback on a later tick of the event loop. Based on async#ensureAsync as module.

Install

npm install ensure-async --save

If you want to use in the browser (powered by Browserify):

bower install ensure-async --save

and later link in your HTML:

<script src="bower_components/ensure-async/dist/ensure-async.js"></script>

Usage

var ensureAsync = require('ensure-async');
 
function sometimesAsync(arg, callback) {
  if (cache[arg]) {
    return callback(null, cache[arg]); // this would be synchronous!!
  } else {
    doSomeIO(arg, callback); // this IO would be asynchronous
  }
}
 
// this has a risk of stack overflows if many results are cached in a row
async.mapSeries(args, sometimesAsync, done);
 
// this will defer sometimesAsync's callback if necessary,
// preventing stack overflows
async.mapSeries(args, ensureAsync(sometimesAsync), done);

API

ensureAsync(fn)

Wrap an async function and ensure it calls its callback on a later tick of the event loop. If the function already calls its callback on a next tick, no extra deferral is added. This is useful for preventing stack overflows (RangeError: Maximum call stack size exceeded) and generally keeping Zalgo contained.

Arguments

  • fn - an async function, one that expects a node-style callback as its last argument

Returns a wrapped function with the exact same call signature as the function passed in.

License

MIT © Kiko Beats

Install

npm i ensure-async

DownloadsWeekly Downloads

3

Version

1.0.0

License

MIT

Last publish

Collaborators

  • avatar