stream.eventNames() broken on 21.2.0+

[Qard]

Version

v21.2.0

Platform

Darwin COMP-JX471G9FQQ 23.2.0 Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:18 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T6000 arm64 arm Darwin

Subsystem

streams

What steps will reproduce the bug?

Use stream.eventNames() on a stream and you'll find it reports having event listeners for events which it does not actually have listeners for due to this _events pre-allocation change which released in 21.2.0.

How often does it reproduce? Is there a required condition?

Always.

What is the expected behavior? Why is that the expected behavior?

stream.eventNames() should only return names of events for which there actually are listeners.

What do you see instead?

All expected event types report having listeners because it's based on Reflect.ownKeys(...) which will see the explicit undefined keys as present and assume that means there are listeners for that event name.

Additional information

No response

[juanarbol]

I will try to fix this one

[Medhansh404]

@juanarbol do you mind if you share how are you planning to approach this issue, do you paln to make changes on the default undefined values or add something/ enhacement that caters to them the undefined listeners so that it won't cause events to be as one? i'm just curious

[juanarbol]

@juanarbol do you mind if you share how are you planning to approach this issue, do you paln to make changes on the default undefined values or add something/ enhacement that caters to them the undefined listeners so that it won't cause events to be as one? i'm just curious

I don't know yet, I will figure that out later.
I will reference the issue once I have something

[Qard]

I suspect eventNames() is called a lot less frequently than the benefits of that pre-allocation PR, so I would suggest changing eventNames to do a more rigorous check that the keys are not only there but also are non-empty arrays.

[Medhansh404]

Hey @Qard can you pls tell me a instance where we are using the eventNames(), it will be a lot easier for me if you can do so!!

[IlyasShabi]

@juanarbol I was looking into the issue, and I found myself creating a PR. I'm not sure if it's the right way to do it, but I would like to know how you will fix it.