MongoDB nodejs updateOne always returning modifiedCount: 0 - node.js

Question

I’m having an issue where I’m attempting to update my document and the change is not being reflected. I suspect MongoDB is finding that my value is somehow the same even though I’ve changed it
const User = require('./assets/models/User.js');
var message = user.messages;
//should be an empty array for right now, can be something like
//['erin': [{ from: ‘erin’, to: ‘erin’, content: ‘test’ }]]
//in the future
if (!message[otherPerson]) message[otherPerson] = [];
await message[otherPerson].push(msg);
//where msg is a msg object
//pushes message into new index
//updates messages with new data
const test = await User.updateOne({ usertag: person }, {
$set: { messages: message }
});
console.log(await test);
I’ve tried multiple formats of updating such as
User.updateOne({ usertag: person }, {
messages
});
where the messages variable is called message in the earlier example
or
User.updateOne({ usertag: person }, {
$set: { messages }
});
and nothing seems to work
I will also mention that this is some rather old code that used to work pretty well. Has something changed in how MongoDB handles updates or am I doing something wrong?

Answer 1

If you want to add a new value to the messages array you should use $push:
const test = await User.updateOne({ usertag: person }, {
$push: { messages: msg }
});
If you want to edit a specific message you should filter by its id and reference the specific array element (I'm assuming that _id is your identifier for message elements):
const test = await User.updateOne({ usertag: person, messages._id: msg._id }, {
$set: {
messages.$.from: msg.from,
messages.$.to: msg.to,
messages.$.content: msg.content,
}
});
Also, you should not await the test result since you already resolved the Promise awaiting the updateOne:
console.log(test);