async.during iteratee callback do not support optional parameter

[thatisuday]

I am using v2.0.0 on client side.

In async.during example, if we pass a optional value in callback of iterate, javascript show error of callback is not a function in truthy functon.

var count = 0;

async.during(
    function (callback) {
        console.warn(arguments);
        return callback(null, count < 5);
    },
    function (callback) {
        count++;
        setTimeout(function(){
          callback(null, count);
        }, 1000);
    },
    function (err, res) {
        console.info(res); // 5 seconds have passed
    }
);

Is there anything I am doing wrong? I guess this is also mentioned in documentation that callback will be passed an error and any arguments passed to the final fn's callback

[thatisuday]

This does same with doDuring

[aearly]

Which 2.0.0 RC version are you using?

[thatisuday]

@aearly 6

[megawac]

Any arguments you pass to callback will be passed to the predicate. Your code can be changed as follows,

var count = 0;

async.during(
    function (callback) {
        return arguments[arguments.length - 1](null, count < 5);
    },
    function (callback) {
        count++;
        setTimeout(function(){
          callback(null, count);
        }, 1000);
    },
    function (err) {
        // 5 seconds have passed
        console.log("done")
    }
);

This probably should be documented, if you're interested send a pull request

[megawac]

@aearly do we want to just remove optional parameters passed to during test functions? Doesn't seem so useful as async won't pass it in on the first call anyway (always undefined first run)

I'd vote scrap the extra args

[aearly]

whilst and until also have the same weird behavior where args from the async callback are only applied on the second test call. I think if you're using args from the fn's callback in the test, you're going to be using do(Whilst|Until|During) instead anyway. We should clarify the docs.