Id deleted on update on MongoDB

[jdumont0201]

Steps to reproduce

Create a new project with CLI
Using CLI, add model, MongoDB datasource, repository and CRUD controller. Add this route to controller

@get('/mymodels/test'})
async test(): Promise<void> {
  const data={name:"title"}
  const p:Mymodel=await  this.mymodelRepository.create(data)
  console.log("Saved entity",p)

  p.name="modified title"
  await this.mymodelRepository.update(p)
  console.log("Modified entity",p)
  return 
}

Current Behavior

On MongoDB, the entity had an id after create, but looses it after update. Result is

Saved entity Mymodel { name: 'title', id: 5d15d7c25ae6d1605cc0b0dc }
Modified entity Mymodel { name: 'modified title' }

In memory DB, result is fine:

Saved entity Mymodel { name: 'title', id: 5d15d7c25ae6d1605cc0b0dc }
Modified entity Mymodel { name: 'modified title', id: 5d15d7c25ae6d1605cc0b0dc  }

In Postgres, result is fine as well (tested with numeric ids):

Saved entity Mymodel { name: 'title', id: 1 }
Modified entity Mymodel { name: 'modified title', id: 1 }

(We are just talking about the runtime variable. The value in db maintains a valid id. )

Expected Behavior

id shouldnt be deleted from updated entity

Link to reproduction sanbox

https://github.com/jdumont0201/loopback-id-issue-demo
(Just edit the datasource json to plug to a MongoDB, couldnt share connection details here)

Versions

Win10
@loopback/cli 1.17.1
@loopback/core": 1.8.4
loopback-connector-mongodb": "^5.0.0
loopback-connector-postgresql": "^3.7.0

Acceptance criteria

• Fix the problem in loopback-connector-mongodb
• Add a new test to https://github.com/strongloop/loopback-next/tree/master/packages/repository-tests to ensure consistent behavior across all connectors.
• if the fix is in mongoDB connector, also add a test in that connector

[bajtos]

@hacksparrow since you have been working with MongoDB recently, would you like to take a look at this issue yourself?

[hacksparrow]

Confirming it is a bug.

Also confirming, it is reproducible in loopback-connector-mongodb 4.2.0 and 3.9.2.

Thanks for reporting @jdumont0201. I will start fixing it.

[bajtos]

@hacksparrow besides fixing the problem in our MongoDB connector, please add a new test to https://github.com/strongloop/loopback-next/tree/master/packages/repository-tests to ensure consistent behavior across all connectors. I'll update acceptance criteria in the issue description accordingly.

[dhmlau]

Would like to get an estimate on the effort to add extra tests so that we can get it done and close this issue. Thanks.

[hacksparrow]

Hmm, I fixed this in July - loopbackio/loopback-connector-mongodb@c5200e2.

Use the latest version of loopback-connector-mongodb.