Result of async.timeout() only works the first time you call it.

[acjohnso25]

What version of async are you using? 2.4.0

Which environment did the issue occur in (Node version/browser version) Node.js 4.7.0

What did you do? Please include a minimal reproducable case illustrating issue.

const async = require('async');

var asyncFn = function (i, done) {
    if (i < 1) {
        setTimeout(done, 200);
    } else {
        setImmediate(done);
    }
};

// wrap function once, call 10 times
var timeoutFn = async.timeout(asyncFn, 100);
var j = 0;
async.whilst(
    function () {
        return j < 10;
    },
    function (done) {
        timeoutFn(j++, function (err) {
            console.log('Test 1 #' + j, err);
            done();
        });
    },
    function (err) {
    }
);

What did you expect to happen? Should only get timeout error the first time it's called.

What was the actual result? Timeout occurs every time it's called, even though the underlying function only takes too long the first time.

[acjohnso25]

This may actually be by design, but if so it wasn't what I expected, and it wasn't indicated in the documentation from what I could see.

Simple workaround is to instead simply wrap the function each time before you call it, i.e.:

// wrap function 10 times
var k = 0;
async.whilst(
    function () {
        return k < 10;
    },
    function (done) {
        async.timeout(asyncFn, 100)(k++, function (err) {
            console.log('Test 2 #' + k, err);
            done();
        });
    },
    function (err) {
    }
);

[hargasinski]

Hi @acjohnso25, I believe you're right that this is bug. It should only give a ETIMEDOUT error on the first call. Thanks for the report, we'll fix as soon as possible.

[acjohnso25]

I guess it's more correct to say that it works until the first timeout...then it always times out. For example, if you change asyncFn to this:

var asyncFn = function (i, done) {
    if (i === 5) {
        setTimeout(done, 200);
    } else {
        setImmediate(done);
    }
};

...then what you see is:

Test 1 #1 undefined
Test 1 #2 undefined
Test 1 #3 undefined
Test 1 #4 undefined
Test 1 #5 undefined
Test 1 #6 { [Error: Callback function "anonymous" timed out.] code: 'ETIMEDOUT' }
Test 1 #7 { [Error: Callback function "anonymous" timed out.] code: 'ETIMEDOUT' }
Test 1 #8 { [Error: Callback function "anonymous" timed out.] code: 'ETIMEDOUT' }
Test 1 #9 { [Error: Callback function "anonymous" timed out.] code: 'ETIMEDOUT' }
Test 1 #10 { [Error: Callback function "anonymous" timed out.] code: 'ETIMEDOUT' }

[aearly]

Yeesh, I almost feel like we should do patch releases back to 2.0.0.

[aearly]

Fixed in v2.4.1