NodeJS & Mongoose, update values in array of objects not working - node.js

Question

I am struggling to update some specific arrays in my UserSchema with the mongoose function findByIdAndUpdate().
This is my UserSchema:
const UserSchema = new mongoose.Schema({
mail: {type: String, required: true, unique: true},
password: {type: String, required: true},
friends: [{id: String}],
prot: [{
id: String,
admin: Boolean,
}]
});
I only want to update the prot element, this is how I want todo this:
User.findByIdAndUpdate(req.body.userId, {
$set: { prot: [{ id: req.body.lockId, admin: req.body.isAdmin }] }, function(err, user) {
if (err) {
return res.status(500).send({
message: err.message || "Some error occured while updating user"
});
}
if (!user) {
return res.status(404).send({
message: "User not found"
});
}
return res.status(200).send(user);
}
})
But when I try to send a request via Postman, I didn't get an response or error..

Answer 1

FindByIdAndUpdate doesn't return updated document per default, you should add option {new:true}. You have mixed brackets too. Do it like below:
User.findByIdAndUpdate(
req.body.userId,
{
$set: {
prot: [{
id: req.body.lockId,
admin: req.body.isAdmin
}]
}
},
{ new: true },
function(err, user) {
if (err) {
return res.status(500).send({
message: err.message || "Some error occured while updating user"
});
}
if (!user) {
return res.status(404).send({
message: "User not found"
});
}
return res.status(200).send(user);
}
);

Answer 2

If you want to update a specific record inside an array of objects. You can do it like this.
User.update(
{ _id: req.body.userId,
prot:
{ $elemMatch: { id: req.body.lockId }}
},
{ $set:
{ prot: { admin: req.body.isAdmin }
}
},(error,result)=>{
if(error){
//handle error
}
console.log(result);
}
)