Func-It

Returns an empty function if one isn't present. Useful for optional callback parameters inside methods.

Usage

To ensure your callback parameter is actually a function and not another value or undefined follow this example. This allows you to make callbacks optional in your methods.

/*
 * Calculates a result and saves it in the database. The callback is optional.
 * callback(err, doc);
 */
function thisIsMyMethod (x, y, callback) {

  // Ensure callback is an empty fn if the parameter isn't provided.
  callback = require('func-it')(callback);

  // Do something...
  var result = x * y;
  return database.save(result, callback);  //no need to check typeof callback === 'function'.

}

Shorthand Empty Function

If you just need quick access to an empty function:

var funcIt  = require('func-it');
var emptyFn = funcIt.emptyFn;

function doSomething() {
  return emptyFn(result);
}