Can not save new _User object after deleting field value

[sadakchap]

New Issue Checklist

• [x] I am not disclosing a vulnerability.
• [x] I am not just asking a question.
• [x] I have searched through existing issues.
• [x] I can reproduce the issue with the latest version of Parse Server.
• [x] I can reproduce the issue with the latest version of Parse Dashboard.

Issue Description

Not able to save or create new objects after deleting one of the field values, using del key after selecting that field cell.

Steps to reproduce

• Click on add new row button
• set value in any field
• select that field and press del key, that should unset that field
• (if any required field, then fill those first) save new row.

Actual Outcome

Can not save new row, getting error You cannot use [object Object] as a query parameter.

Expected Outcome

should be able to save new row.

Pull Request

• PR: #FILL_THIS_OUT

Environment

Dashboard

• Parse Dashboard version: 2.1.0
• Browser (Safari, Chrome, Firefox, Edge, etc.): Chrome
• Browser version: Version 92.0.4515.107 (64-bit)

Server

• Parse Server version: 4.5.0
• Operating system: Ubuntu 20.04.2 LTS
• Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): local

Database

• System (MongoDB or Postgres): MongoDB
• Database version: 3.3
• Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): remote host

Logs

https://user-images.githubusercontent.com/44117648/127895519-d8cf0bc8-2ff8-49a3-9ee3-8b7bb229afe7.mp4

[mtrezza]

Thanks for reporting. Interesting find, I think we should try to merge all of the pending PRs over the next days and then see which issues still occur. A lot of PRs are changes in the Data Browser, so maybe the issue will self-resolve.

[mtrezza]

I am able to reproduce this with the latest version. The reason is that deleting a field creates a delete operation, although this is a new object to be saved:

_User request:

{
    "authData": {},
    "username": {
        "__op": "Delete"
    }
}

I classify this as bug with severity 4 (trivial).

The solution is to not set a delete operator when deleting a field while creating a new object.