Maybe call a callback if it's a function
npm install maybe-callback> Maybe call a callback if it really is who it says it is.
Node.js is required. To install, type this at the command line:
``shell`
npm install maybe-callback
js
var maybeCallback = require('maybe-callback');
function callback(arg) {
return arg + 1;
}maybeCallback(callback)(1); //=> 2
maybeCallback(null)(1); //=> undefined
var once = maybeCallback.once(callback);
once(1); //=> 2
once(1); //=> undefined
``
[npm-image]: https://img.shields.io/npm/v/maybe-callback.svg
[npm-url]: https://npmjs.org/package/maybe-callback
[travis-image]: https://img.shields.io/travis/robskillington/maybe-callback.svg
[travis-url]: https://travis-ci.org/robskillington/maybe-callback