update/upsert: _id is generated even if you send a pre-generated _id the json object

[ejbp]

Consider this lines of code with an empty db file:

[...]

//I need to pre-generate the _id of this object and not use a auto-generated _id 
var obj = {
  "_id": "xxxxxxx",
  "name":  "test"
};

console.log("Before: ", obj);
db.records.update({ _id : "xxxxxxx" },  obj, {multi: false, upsert: true});
console.log("After: ", obj);

[...]

The output will be:

Before: { "_id": "xxxxxxx", "name":  "test"}
After: { "_id": "6aec8d48d5284def9c3c85428b506d95", "name":  "test"}

//being '6aec8d48d5284def9c3c85428b506d95' the new generated _id when it should be 'xxxxxxx'

After looking into the module code, I noticed that you don't verify if the _id already exists:

filename: collection.js

coltn.update = function(query, data, options) {
        var ret = {},
            collection = JSON.parse(util.readFromFile(this._f)); // update
        var records = util.finder(collection, query, true);
        if (records.length) {
            if (options && options.multi) {
                collection = util.updateFiltered(collection, query, data, true);
                ret.updated = records.length;
                ret.inserted = 0;
            } else {
                collection = util.updateFiltered(collection, query, data, false);
                ret.updated = 1;
                ret.inserted = 0;
            }
        } else {
            if (options && options.upsert) {
                //It would be nice if you verify if the _id exists and only create a new one if not 
                data._id = uuid.v4().replace(/-/g, ''); 
                collection.push(data);
                ret.updated = 0;
                ret.inserted = 1;
            } else {
                ret.updated = 0;
                ret.inserted = 0;
            }
        }
        util.writeToFile(this._f, collection);
        return ret;
    };