MongoDB push into nested array - node.js

Question

I have this scheme
{
"_id": {
"$oid": "5e187b1791c51b4b105fcff0"
},
"username": "test",
"email": "test#test.com",
"role": "admin",
"userScoreFantasy": {
"tournaments": [
{
"tournament_id": {
"$oid": "5e1892fb480f344830a3f160"
},
"predictions": [],
"score": null
},
{
"tournament_id": {
"$oid": "5e189f5f8d88292754e10b37"
},
"predictions": [],
"score": null
}
],
"totalScore": null
},
}
I want to do this :
Find user with a predefined user id
Pass all userScoreFantasy.tournaments array to find a specific tournament id
Push into the found tournament predictions array an object like this one :
{
score,
"match_id": foundMatch._id
}
So the tournaments array will become :
[
{
"tournament_id": {
"$oid": "5e1892fb480f344830a3f160"
},
"predictions": [
"score" : 200,
"match_id": "5e1892fb480f34faw21410"
],
"score": null
},
]
I tried to do this :
Users.update({
"_id": prediction.user_id,
"userScoreFantasy.tournaments": {
"$elemMatch": {
"tournament_id": foundMatch.tournament_id
}
}
}, {
"$push": {
"userScoreFantasy.tournaments.$.predictions": {
score,
"match_id": foundMatch._id
}
}
})
But the array is not updating.
EDIT :
Working call :
Users.updateOne({
"_id": ObjectID(prediction.user_id),
}, {
$addToSet: {
"userScoreFantasy.tournaments.$[element].predictions": {
score,
"match_id": foundMatch._id
}
}
}, {
arrayFilters: [{
"element.tournament_id": ObjectID(foundMatch.tournament_id)
}]
}
)

Answer 1

You should use the position indentifier to update your arrays, like so:
Users.updateOne(
{
"_id": prediction.user_id,
},
{
$addToSet: {
"userScoreFantasy.tournaments.$[element].predictions": {
score,
"match_id": foundMatch._id
}
}
},
{arrayFilters: [{"element.tournament_id": foundMatch.tournament_id}]}
);