Stubbing a function in sinon to return different value every time it is called

I have a function as shown below:

function test(parms) {
        var self = this;
        return this.test2(parms)
        .then(function (data) {
            if (data) {
                return ;
            }
            else {
                return Bluebird.delay(1000)
                .then(self.test.bind(self, parms));
            }
        }.bind(self));
    };

I am trying to write unit test cases for this function. I am using sinon stub to mock the functionality of the function test2.

I wrote a test case where test2 writtens true and therfore the test function successfully completes execution. However I want a test case where on the first instance test2 returns false, it waits for delay and next time test2 returns true. For that I wrote my test case as below:

var clock;
var result;
var test2stub;
var count = 0;

before(function () {
    clock = sinon.useFakeTimers();
    //object is defined before
    test2stub = sinon.stub(object,"test2", function () {
        console.log("Count is: " + count);
        if (count === 0) {
            return (Bluebird.resolve(false));
        }
        else if (count === 1) {
            return (Bluebird.resolve(true));
        }
    });
    clock.tick(1000);

    object.test("xyz")
    .then(function (data) {
        result = data;
    });
    clock.tick(1000);
    count = count + 1;
    clock.tick(1000);
});

after(function () {
    test2stub.restore();
    clock.restore();
});

it("result should be undefined. Check if test2 returned false first & true next", function () {

    expect(result).to.be.undefined;
});

In the logs it shows that count has value 0 only.