is-async

A simple method to guess whether or not a given method is asynchronous.

Install

npm install is-async

Usage

var isAsync = require('is-async');
 
function foo(bar, callback) {
    callback(bar*2);
}
 
isAsync(foo, 2); // Returns true, isAsync was told a function with two arguments is probably true
 
function forceAsync(bar, baz, callback) {
    callback(bar*baz);
}
 
forceAsync.async = true; // Adding an ``async`` property to the function
 
isAsync(forceAsync); // Returns true, the ``async`` property takes precedence
 
function forceSync(bar, baz) {
    return bar*baz;
}
 
forceSync.sync = true; // Similar override property
 
isAsync(forceSync, 2); // Returns false, even though its considered "probably async" because of the ``sync`` property.

License (MIT)

Copyright (C) 2012-2013 by David Ellis

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.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.