How to increment a nested object field ?

[sadortun]

New Issue Checklist

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

Issue Description

This is a simpler case version of issue #6687. I'm not sure if i'm doing anything wrong, but i think this should work

I'm trying to increment a value of a newly created object.

Ex:

db.test.findOneAndUpdate(
    {"_id":"20mMYzLTjx"} ,
    {$inc:{ "a.b.c.d" : 1 }}
)

Steps to reproduce

const obj= await Parse.Object
    .extend('test')
    .createWithoutData('20mMYzLTjx').fetch()

// obj.get('a') === {}   (my schema defaults a to {}

obj.increment('a.b.c.d' , 1 )
await obj.save()

Actual Outcome

TypeError: Cannot read property 'd' of undefined at Object.estimateAttributes (.....parse-server\node_modules\parse\lib\node\ObjectStateMutations.js:234:28)

Seems to me that https://github.com/parse-community/Parse-SDK-JS/blob/master/src/ObjectStateMutations.js#L140

          for (let i = 0; i < fields.length - 1; i++) {
-            object = object[fields[i]];
+            object = object[fields[i]] || {}; 
          }

Expected Outcome

Path a.b.c.d get created and persisted

Failing Test Case / Pull Request

• 🤩 I submitted a PR with a fix and a test case.
• 🧐 I submitted a PR with a failing test case.

Environment

Server

• Parse Server version: v4.5.0 / 3d76643286d41b954b6c8e2d6614657c891a31e7
• Operating system: Win 10
• Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): local

Database

• System (MongoDB or Postgres): Mongo
• Database version: 4.4.4
• Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): remote/self hosted

Client

• SDK (iOS, Android, JavaScript, PHP, Unity, etc): Js
• SDK version: 2.17.0

Logs

[dplewis]

Nice catch! We will look into this shortly.

[dplewis]

@sadortun A little back history. Nested objects were originally supposed to be for simple objects as complex objects could be broken up into different fields and classes.

If you have time check out this thread