Prevent _id field from being supplied in a MongoDB query - node.js

Question

I'm using Mongoose in NodeJS to control a MongoDB database.
I'm creating an API and for obvious security reasons, I want to prevent the auto generated document _id field from getting replaced by a manually generated one in the API request.
Schema:
{ name: String }
Creating a document:
const record = {
_id: '5e35517cc894c90327a34baf'
name: 'bob'
}
const insertRecords = async () => {
await Quiz.create(record);
};
insertRecords();
Results in the following document:
{
_id: '5e35517cc894c90327a34baf'
name: 'bob'
}
As can be seen, the _id supplied in the query, as long as it's a valid ObjectID, would replace the _id that was supposed to be auto generated by mongo.
Is there a way to check if this _id field is in the query so that I can reject the API request? The .create method triggers the pre save middleware hook which would always have the _id of the final document so I cannot depend on it to know whether the _id was in the query or it's the auto generated one.
The only option I found is to disable the _id field altogether but this does not make sense.

Answer 1

Solution #1 - Use .create() method with an explicit object.
It's actually easier than you think. This is self-explanatory - we only define what we want to allow. Mongoose will ignore anything that's not in the object.
const record = {
_id: '5e35517cc894c90327a34baf'
name: 'bob'
}
const insertRecords = async () => {
await Quiz.create({
name: record.name // only allow names.
});
};
insertRecords();
Solution #2 - Define a function to clear unwanted objects.
You can define a helper function to clear out unwanted fields.
const filterObj = (obj, ...allowedFields) => {
const newObject = {};
// If the current field is one of the allowed fields, keep them in the new object.
Object.keys(obj).forEach((el) => {
if (allowedFields.includes(el)) {
newObject[el] = obj[el];
}
});
return newObject;
};
How to use:
const filteredRecord = filterObj(record, 'name'); // arbitrary list of allowed fields. In this case, we'll only allow 'name'.
await Quiz.create(filteredRecord);