javascript - 如何使用异步重构 Node js 代码并避免回调 hell

Question

我对 Node 相对较新，并且正在尝试了解如何异步或 promise 或任何使我的代码更好的内容。这是我的代码示例

router.post('/delete', function (req, res) {
    var bus_id = req.body.selected[0];
        Bus.remove({_id: bus_id}, function (err) {
            if (err) {
                res.json({status: "error", message: "please enter a valid bus_id"});
            } else {
                User.remove({refid:bus_id},function(err){
                    if (err) {
                        res.json({status: "error", message: "bus user wasn't deleted"});
                        return;
                    } else {
                        res.json({status: "success",message: "bus and bus user were deleted"});
                    }
                });
            }
        });
});

我读到了有关异步和 promise 的内容，应用到我的代码的最佳方法是什么？

Answer 1

我个人会选择 Promise。它可能看起来像这样。

router.post('/delete', function (req, res) {
  var bus_id = req.body.selected[0];

  Bus.remove({_id: bus_id}).exec().then(function(bussRemoved) {
    return User.remove({refid: bus_id}).exec();
  }).then(function(userRemoved) {
    res.json({status: "success",message: "bus and bus user were deleted"});
  }).catch(function (err) {
    res.json({status: "error", message: "please enter a valid bus_id"});
  });
});