Mongoose right promise rejection handling

问题

I'm bit fighting with promise pattern in nodeJS

I'm looking for user in db and then saving new entity with user reference, but when user is not in db, I should return rejection, but I'm not sure how to do it properly.

is there way how to do it more nicely?

btw: sorry, coffeescript :-[

User.findOne({'fbId':userData.me.id}).exec().then((doc)->
  if !doc? then return new Promise (resolve,reject)->reject(404)

  video = new Video({
    user:doc
    state: "queue"
    createdAt: new Date()
  })

  video.save().exec()
)

回答1:

You can use throw inside then callbacks to reject them. Or, instead of using the Promise constructor like that, you might also use Promise.reject(404).

User.findOne
  fbId:userData.me.id 
.exec().then (doc)->
  if !doc? 
    throw new Error 404

  video = new Video
    user: doc
    state: "queue"
    createdAt: new Date
  video.save().exec()

来源：https://stackoverflow.com/questions/28695092/mongoose-right-promise-rejection-handling