caolan/async — pull request #318 by aearly (2013-05-22 01:59:55+00:00)
Title: Pass params from doUntil/doWhilst callbacks to the test function

Pretty simple, it just passes the callback results from the `doWhilst` and `doUntil` iterators to the test function. This allows you to do something like (contrived example):

```javascript
async.doWhilst(pollForSomething, _.isUndefined, callback);
```
rather than

```javascript
var value;
async.doWhilst(function(cb) {
pollForSomething(function (err, res) {
if(err) return cb(err);
value = res;
cb();
});
}
, function test() {
return !value;
},
callback);
```