block.js

router.get('/2', function (req, res) {
    Block.findOne({ps: 1}).exec().then(function(block) {
        //原本你的cb那一塊
        res.render('indexTest', {
            title: '首頁',
            user: req.session.user,
            block: block,
            success: req.flash('success').toString(),
            error: req.flash('error').toString()
        });
    }, function(err) {
        //發生錯誤的cb
        next(err);
    });
});