findOneAndReplace upsert not generating _id

[kathirsvn]

When the findOneAndReplace API is called with upsert flag set to true, the new document is generated with the given properties in the replacement part of the request, but the _id is not generated. In the below example, you could see _id and upsertedId are not set in the final response.

To replicate the issue;

http: --- request POST http://localhost:8181/v1 
{
  "createNamespace": {
    "name": "testks1"
  }
}

http: --- request POST http://localhost:8181/v1/testks1 
{
  "createCollection": {
    "name": "products",
    "options": null
  }
}

http: --- request POST http://localhost:8181/v1/testks1/products {
  "findOneAndReplace": {
    "filter": {
      "name": "Product 25"
    },
    "replacement": {
      "name": "Product 25",
      "isCertified": false,
      "price": 20
    },
    "options": {
      "upsert": true,
      "returnDocument": "after"
    }
  }
}


http: --- response 200 POST http://localhost:8181/v1/testks1/products 
{
  "data": {
    "document": {
      "_id": null,
      "name": "Product 25",
      "isCertified": false,
      "price": 20
    }
  },
  "status": {
    "matchedCount": 0,
    "modifiedCount": 0,
    "upsertedId": null
  }
}