Check if Obejct is Empty: Mongoose Nested/Embedded Document - node.js

Question

In my documents pre save hook, I check if all the properties from the nested property accident exist and have correct values. If accident does not exist at all this is also fine.
When I'm trying to save a doc which has no value on the nested property accident of my doc it still goes into my custom validation rules. This is because I fail to detect if this nested object is empty.
Property in the Schema
prescriptionSchema = mongoose.Schema({
accident: {
kind: String, #accident, workAccident,
date: Date,
company: String
},
...
Pre Save Hook
console.log _.isEqual(data.accident, {}) #false
console.log JSON.stringify data.accident #{}
console.log JSON.stringify data.accident == JSON.stringify {} #false
console.log JSON.stringify {} #{}
console.log Object.keys(data.accident).length #14
for key, value of data.accident
console.log key, value #gives me basically the whole document with functions etc.
Current Detection (not good code)
if data.accident? && (data.accident['kind'] || data.accident['date'] || data.accident['company']) #=> do validation
Seed
newRecipe = new RecipeModel()
for key, value of recipe
newRecipe[key] = value
newRecipe.save((err, result) ->
return next err if err?
return next "No Id" if !result._id?
return next null, result._id
)
I tried {}, null and nothing as values for recipe.accident.
Mongoose Version: 4.0.2
Node Version: 5.9

Answer 1

This solution worked although I now have _ids on the embedded objects which I don't need.
I moved out the object from the main schema and defined it as a own sub schema:
drugSchema = mongoose.Schema({
name: String,
exchangeable: Boolean
})
accidentSchema = mongoose.Schema({
kind: String, #accident, workAccident,
date: Date,
company: String
})
prescriptionSchema = mongoose.Schema({
drugs: [drugSchema],
dutiable: Boolean,
accident: accidentSchema,
...
After this, the object is undefined in the pre save hook.

Answer 2

By default, mongoose won't save empty objects. You need to disable the minimize option in your Schema.
prescriptionSchema = mongoose.Schema({
accident: {
kind: String, #accident, workAccident,
date: Date,
company: String
},
...
}, {
minimize: false
})
Source : http://mongoosejs.com/docs/guide.html#minimize
UPDATE : If it is not saving the object, you can try to use the markModified() method (http://mongoosejs.com/docs/schematypes.html#mixed).
And for your checking problem, you can perform a function which will check your fields. Here's two examples : https://jsfiddle.net/ew2um2dh/13/