async.waterfall is not working with Sinon.JS fake timers in Node.js

[rstuven]

Using async.series, the following example works just fine.

var async = require("async");
var sinon = require("sinon");

var clock = sinon.useFakeTimers();

async.series([
    function fn1(cb) {
        console.log("fn1");
        setTimeout(function(){
            cb();
        }, 100);
    },
    function fn2(cb) {
        console.log("fn2");
        cb();
    }
]);

clock.tick(1000);

But if we change async.series by async.waterfall, the program exits before fn2 is called.

var async = require("async");
var sinon = require("sinon");

var clock = sinon.useFakeTimers();

async.waterfall([
    function fn1(cb) {
        console.log("fn1");
        setTimeout(function(){
            cb();
        }, 100);
    },
    function fn2(cb) {
        console.log("fn2");
        cb();
    }
]);

clock.tick(1000);

UPDATE: In the browser, async.waterfall works fine.

<script type="text/javascript" src="http://sinonjs.org/releases/sinon-1.3.1.js"></script>
<script type="text/javascript" src="https://raw.github.com/caolan/async/master/dist/async.min.js"></script>
<script type="text/javascript">

var clock = sinon.useFakeTimers();

async.waterfall([
    function fn1(cb) {
        console.log("fn1");
        setTimeout(function(){
            cb();
        }, 100);
    },
    function fn2(cb) {
        console.log("fn2");
        cb();
    }
]);

clock.tick(1000);

</script>

[rstuven]

async.auto works fine in Node.js too:

var async = require("async");
var sinon = require("sinon");

var clock = sinon.useFakeTimers();

async.auto({
    "f2": ["f1", function f2(cb) {
        console.log("fn2");
        cb();
    }],
    "f1": function f1(cb) {
        console.log("fn1");
        setTimeout(function(){
            cb();
        }, 100);
    }
});

clock.tick(1000);

[rstuven]

I found the source of the issue and a way to "patch" async so it works nicely with Sinon.JS:

if (typeof sinon === "object" && typeof sinon.timers === "object") {
    (function(){
        var nextTick = async.nextTick;
        async.nextTick = function(fn) {
            if (global.setTimeout === sinon.timers.setTimeout)
                nextTick(fn);
            else
                global.setTimeout(fn, 0);
        };
    })();
}

[statico]

You're not crazy. We had to do something similar when using fake timers, too.

[eloone]

If you only need to fake the date you can do sinon.useFakeTimers('Date'), it will work since the problem with async.waterfall comes from sinon faking setIntermediate see #609. Read the useFakeTimers doc to only fake the method you want to fake.