mongoose findOneAndSave and pre hook, and setting an initial value (addedOn date) - node.js

Question

I am new to mongoose and honestly have a ton of reading to do still, but I am working on a small pet project that reads and writes to a mongo db. In this instance I would like to use mongoose to assure a consistent document model.
The problem is assuring default valuesin both an insert and update operations independently. In particualr I am referring to addedOn and updatedOn field respectively. The method I am calling for persistence is the findOneAndUpdate which now has support for middleware hooks (as of 4.0).
I was able to get the basic hook to work (applying the updatedOn date every time), but have been unable to figure out how to add suport (the mongoose way) for the insert case where the addedOn is defaulted. This is the simple schema and hook (attmpeting to handle insert and update):
const TestSchema = new Schema({
id : ObjectId,
name : String,
addedOn : { type: Date, default: Date.now },
updatedOn : { type: Date, default: Date.now }
});
TestSchema.pre('findOneAndUpdate', function(next) {
console.log('hook::findOneAndUpdate')
// update defaults
this.update({addedOn: {$exists:true}},{
$set: {
updatedOn: new Date()
}
})
// insert defaults
this.update({addedOn: {$exists:false}},{
$set: {
addedOn: new Date(),
updatedOn: new Date()
}
})
next();
});
No surprise (because it is really swag) it is not working. THis inserts a row every time the app is run. It appears if adding a criteria to the update method overwrites the default match (haven't dug into the source).
This is my initial snippet for the solely update case and it finds the row and updates correctly, but as mentioned cannot handle the addedOn (it would update it everytime)
TestSchema.pre('findOneAndUpdate', function(next) {
console.log('hook::findOneAndUpdate')
this.update({},{
$set: {
updatedOn: new Date()
}
})
next();
});
Driving all of this is this snippet (to keep the code as close to the idiom of the folktale implmentation of the application I am working on)
mongoose.connect('mongodb://localhost/network');
const model = mongoose.model('TestSchema', TestSchema)
const schema = TestSchema
const collection = model
const findOneAndUpdate = (collection) => {
return (criteria, record) => {
return new Task((reject, resolve) => {
const callback = (error, data) => {
if (error) {
reject(error)
}
else {
resolve(data)
}
}
collection.findOneAndUpdate(criteria, record, {upsert: true}, callback)
})
}
}
const upsert = findOneAndUpdate(collection)
upsert({name: "me"}, {name: "me"}).fork(console.log, console.error)
I could modify my findOneAndUpdate function to add the addedOn - but I would really like to use the mongoose hooks properly.

Answer 1

Well here is one answer, although it requires a second "save" after the findOne and update:
const mongoose = require('mongoose')
const Schema = mongoose.Schema
, ObjectId = Schema.ObjectId
, Task = require('data.task') ;
const TestSchema = new Schema({
id : ObjectId,
name : String,
genre: {type: String, default: 'Action'},
addedOn : { type: Date, default: Date.now, setDefaultsOnInsert: true },
updatedOn : { type: Date, default: Date.now }
});
TestSchema.pre('findOneAndUpdate', function(next) {
console.log('hook::findOneAndUpdate')
this.update({},{
$set: {
updatedOn: new Date()
}
})
next();
});
mongoose.connect('mongodb://localhost/network');
const model = mongoose.model('TestSchema', TestSchema)
const findOneAndUpdate = (originalModel) => {
return (criteria, record) => {
return new Task((reject, resolve) => {
const callback = (error, updatedModel) => {
if (error) {
reject(error)
}
else {
if(!updatedModel) {
resolve(null)
}else {
// this looks to be required to apply defaults from the Schema
updatedModel.save((error) => {
if (error) {
reject(error)
}
resolve(updatedModel)
})
}
}
}
originalModel.findOneAndUpdate(criteria, record, {upsert: true}, callback)
})
}
}
const upsert = findOneAndUpdate(model)
upsert({name: "me"}, {name: "me"}).fork(console.log, console.error)
I don't love it... BUT it works.