// Returns a wrapper function that returns a wrapped callback // The wrapper function should do some stuff, and return a // presumably different callback function. // This makes sure that own properties are retained, so that // decorations and such are not lost along the way. module.exports = wrappy function wrappy (fn, cb) { if (fn && cb) return wrappy(fn)(cb) if (typeof fn !== 'function') throw new TypeError('need wrapper function') Object.keys(fn).forEach(function (k) { wrapper[k] = fn[k] }) return wrapper function wrapper() { var args = new Array(arguments.length) for (var i = 0; i < args.length; i++) { args[i] = arguments[i] } var ret = fn.apply(this, args) var cb = args[args.length-1] if (typeof ret === 'function' && ret !== cb) { Object.keys(cb).forEach(function (k) { ret[k] = cb[k] }) } return ret } }