You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
34 lines
905 B
34 lines
905 B
3 years ago
|
// 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
|
||
|
}
|
||
|
}
|