| // 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 | |
|   } | |
| }
 |