utilise/proxy.js

Lean JavaScript Utilities as Micro-libraries

var is = require('./is')
  , identity = require('./identity')

module.exports = function proxy(fn, ret, ctx){ 
  return function(){
    var result = (fn || identity).apply(ctx || this, arguments)
    return is.fn(ret) ? ret.call(ctx || this, result) : ret || result
  }
}