odin-javascript-exercises/node_modules/run-async/README.md
2017-12-15 12:56:14 -06:00

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Run Async
=========
[![npm](https://badge.fury.io/js/run-async.svg)](http://badge.fury.io/js/run-async) [![tests](https://travis-ci.org/SBoudrias/run-async.svg?branch=master)](http://travis-ci.org/SBoudrias/run-async) [![dependencies](https://david-dm.org/SBoudrias/run-async.svg?theme=shields.io)](https://david-dm.org/SBoudrias/run-async)
Utility method to run a function either synchronously or asynchronously using a series of common patterns. This is useful for library author accepting sync or async functions as parameter. `runAsync` will always run them as an async method, and normalize the multiple signature.
Installation
=========
```bash
npm install --save run-async
```
Usage
=========
Here's a simple example print the function results and three options a user can provide a function.
```js
var runAsync = require('run-async');
var printAfter = function (func) {
var cb = function (err, returnValue) {
console.log(returnValue);
};
runAsync(func, cb)(/* arguments for func */);
};
```
#### Using `this.async`
```js
printAfter(function () {
var done = this.async();
setTimeout(function () {
done(null, 'done running with callback');
}, 10);
});
```
#### Returning a promise
```js
printAfter(function () {
return new Promise(function (resolve, reject) {
resolve('done running with promises');
});
});
```
#### Synchronous function
```js
printAfter(function () {
return 'done running sync function';
});
```
### runAsync.cb
`runAsync.cb` supports all the function types that `runAsync` does and additionally a traditional **callback as the last argument** signature:
```js
var runAsync = require('run-async');
// IMPORTANT: The wrapped function must have a fixed number of parameters.
runAsync.cb(function(a, b, cb) {
cb(null, a + b);
}, function(err, result) {
console.log(result)
})(1, 2)
```
If your version of node support Promises natively (node >= 0.12), `runAsync` will return a promise. Example: `runAsync(func)(arg1, arg2).then(cb)`
Licence
========
Copyright (c) 2014 Simon Boudrias (twitter: @vaxilart)
Licensed under the MIT license.