beforeSave() hook causes "Object Not Found" error

[drhuanliu]

Issue Description

I just upgrade from Parse Server 2.7 to 3.9, and this new issue starts to happen:

• We save a bunch of PFObjects from iOS in bulk with PFObject.saveAll(inBackground: array.....
• In ParseServer, we have a beforeSave, and afterSave hook to do extra steps
• When saving more than one object, the server would return "Object Not Found" error

I trace the error to line 209 of RestWrite.js. Apparently, this call

databasePromise = this.config.database.create(this.className, this.data, this.runOptions, true);

does not return back an object, resulting in throwing an exception.

Here is what I know:

• Problem does not happen in 2.7
• Problem does not happen if just save one object
• Problem does not happen if I do not declare the beforeSave function
• Problem does happen if I declare the beforeSave function, even if the function is empty (doing nothing)

Could you please take a look at that section of the RestWrite.js code, and see what could potentially be causing it to raise an exception?

Steps to reproduce

• Write a cloud code function with beforeSave for a class X
• Save an array of class X objects from iOS clients

Expected Results

• I expect all saves to be successful

Actual Outcome

• Get "object not found" exception

Environment Setup

• Server

  • parse-server version (Be specific! Don't say 'latest'.) : 3.9
  • Operating System: Windows
  • Hardware: Azure cloud
  • Localhost or remote server? (AWS, Heroku, Azure, Digital Ocean, etc): Azure

• Database

  • MongoDB version: 3.2.1 Community
  • Storage engine: not sure
  • Hardware: Azure
  • Localhost or remote server? (AWS, mLab, ObjectRocket, Digital Ocean, etc): Azure

Logs/Trace

Include all relevant logs. You can turn on additional logging by configuring VERBOSE=1 in your environment.

[dplewis]

If you remove the beforeSave hook do the objects save?
Does your objects exist in the DB?

[drhuanliu]

Yes, if I remove beforeSave hook, object saves and exists in DB.

I may have isolated the issue already. I added some logs, it seems that if one of the Number object field is 0, the this.config.database.create call will fail to return an object. I will upload some logs later tonight.

[dplewis]

@drhuanliu any updates?

[wqzyow]

Same issue here. beforeSave() was not triggered for only one parse subclass. After investigation/debugging, turned out I was using a field/column named "length" on that parse subclass. Renaming that column fixed the issue.

Believe the error is being thrown because of one line in RestWrite.js:

      if (!result || result.length <= 0) {
        throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, 'Object not found.');
      }

result.length returns 0 when the 'length' column value is 0.

[dplewis]

@wqzyow That is interesting. We can do a PR for that. @drhuanliu Are you experiencing anything similar?

[sunshineo]

This can be reproduced without involving beforeSave
Just create a class with column length with type Number and try post to it
This works {"length":1}
This does not {"length":0} and returns that error

[mtrezza]

Thanks for confirming. Would you be willing to open a PR for this and start by adding a failing test case?