emptyFunction (Javascript)

The module exports nothing but an empty function.

install

npm install emptyfunction

Get the empty function from the module

var emptyFunction = require('emptyfunction');

Now use the function whenever there is an optional callback within your code.

function example(cb) {
  if (!cb) cb = emptyFunction
  for (var i = 0; i < 1337; i++) cb()
}

Sometimes you might need to verify whether the callback is an empty function.

If you have access to the emptyFunction object you can do a strict comparison.

this.someFunction === emptyFunction

If not, a more hacky solution is to use the name of the function:

this.someFunction.name === 'emptyFunction'

A simple function to check whether we're dealing with a callback that exists:

function isCallback(cb) {
  return (cb && cb !== emptyFunction) ? true: false
}

A simple function to make assigning callbacks easier:

function setCallback(cb) {
  return (isCallback(cb)) ? cb : emptyFunction
}

// Usage:
var myAlwaysWorkingCallback = setCallback(cb)

MIT