Messages: Filters: Search filter does not work for value equal to null

[BaoKhanhFontAriel]

Issue submitter TODO list

• I've looked up my issue in FAQ
• I've searched for an already existing issues here
• I've tried running main-labeled docker image and the issue still persists there
• I'm running a supported version of the application which is listed here

Describe the bug (actual behavior)

I add filter record.value.name == null to search all values that have name equal to null but it shows no message found

Expected behavior

There should be 1 message found with name == null

Your installation details

Version is kafbat-ui-v1.0.0.jar, I run it with jar file

Steps to reproduce

1. Produce 2 message {"name":"Sam", "age": 25} and {"name": null, "age": 24}
2. Add filter record.value.name == null
3. Result shows no message found

Screenshots

Logs

No response

Additional context

No response

[github-actions]

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[sixdouglas]

Hi, I'd be happy to work on this issue

[sixdouglas]

I've played a little around this issue. I can reproduce the behaviour in a unit simple test, using just the plain CEL library.

I found this in the CEL lib documentation ( here ):

The null value is written null. It is used in conversion to and from protocol buffer and JSON data, but otherwise has no built-in meaning in CEL. In particular, null has its own type (null_type) and is not necessarily allowed where a value of some other type is expected.

I didn't manage to compare anything (the name key in the example below) to null. Using an expression like record.value.name == null to validate on a map like this :

Map<String, Object> objectKeys = new HashMap<>();
objectKeys.put("name", null);
objectKeys.put("age", 24);
Map<String, Object> valueKeys = new HashMap<>();
valueKeys.put("value", objectKeys);
Map<String, Map<String, Object>> recordKeys = new HashMap<>();
recordKeys.put("record", valueKeys);

Gives me an output result like this:

unknown {
  exprs: 3
}

Do you know a specific way to do this kind of comparison using this library?

[yeikel]

Can you send a draft PR with your progress so far? I'd like to try/experiment what the change looks like along with you

[Haarolean]

I didn't manage to compare anything

yeah me neither, I've tried typeof and some other things, nothing worked (which worked fine here: https://playcel.undistro.io/ ). Most likely, our CEL env requires adjustments (see MessageFilters#createCompiler and MessageFilters#createRuntime).