How to wait for the promise is fulfilled? about bluebird HOT 1 CLOSED

function validateData(input) {
    //Some normal checks on input
    if (input.data1 == null) {
        return Promise.cast(false);
    }
    //Now promises
    return Promise.all([
        Products.findAsync(input.productid),
        Users.findAsync(input.userid)
    ]).spread(product, user) {
        if (product == null) {
            return false;
        }
        if (user == null) {
            return false;
        }
        return true;
    });
}

app.get("/", function (req, res) {
    validateData(res.input).then(function (valid) {
        if (valid) {
            res.end("valid");
        }
        else {
            res.end("Not valid");
        }
    }).error(function (e) {
        console.error(e);
        res.status(500);
        res.end("Something went wrong, please try again later");
    });
});