updateOne(..., { upsert: true}) Cannot locate upserted record.

[sinclairzx81]

Hi, thanks for this library, it is very useful. I may have stumbled across a small issue with upsert and subsequent matching on Mongo identifiers. A repro of the issue is below.

// Using updateOne(..., { upsert: true }) with an existing identifier. The expectation here is that 
// upserted record would use the identifier passed in the filter.  However that doesn't
// appear to be the case.
async function repro() {
    const mongo_mock   = require('mongo-mock')
    const client       = new mongo_mock.MongoClient()
    const db           = await client.connect('mongodb://localhost:27017/db')
    const vectors      = db.collection('vectors')
    
    const _id          = new mongo_mock.ObjectID()
    const updateResult = await vectors.updateOne({ _id }, { x: 1, y: 2, z: 3 }, { upsert: true })
    const findResult   = await vectors.findOne({ _id })

    console.log(updateResult) // result: { result: { ok: 1, nModified: 1, n: 1 }, ... }
    console.log(findResult)   // result: null
                              // expect: { _id: ObjectId(...), x: 1, y, 2, z: 3 }
}

repro()

I can confirm the record is being written with this subsequent repro, however unsure about the encoding used to express the identifier, or why this is failing to match. (Edit: it appears mongo-mock may just be ignoring the _id for the filter and generating a new _id in these cases)

async function repro2() {
    const mongo_mock   = require('mongo-mock')
    const client       = new mongo_mock.MongoClient()
    const db           = await client.connect('mongodb://localhost:27017/db')
    const vectors      = db.collection('vectors')
    
    const _id          = new mongo_mock.ObjectID()
    const updateResult = await vectors.updateOne({ _id }, { x: 1, y: 2, z: 3 }, { upsert: true })
    const findResult   = await vectors.findOne({ }) // omit

    console.log(_id)         // ObjectID(620ca8968d741e4d0099b507)
    console.log(findResult)  // {
                             //      x: 1,
                             //      y: 2,
                             //      z: 3,
                             //      _id: { _bsontype: 'ObjectID', id: 'b\f¨\x96\x8Dt\x1EM\x00\x99µ\x07' }
                             // }                                  ^
                             //                         ObjectID is returned with the .id encoded as an escaped string
}

repro2()

Running comparative tests against MongoDB itself yields the expected behavior.

I have the same issue, the _id returned by searching for the upserted item is null.