Sometimes an new view uses a Layout animation previously used on a different view

[dcorbin]

Description

This bug is not easily reproducible and appears to be non-deterministic.

I have two types of animated views that use entering One uses a Keyframe to do translation along a path based on a user-selection (or sometimes a programmatic selection based on context) This is often visually distinct, because it's often randomly generated movement. The other is strictly a FadeIn. Each type of animated view exists been many times (as many as 20) times on a given screen. If I use the app sufficiently (something in the range of 100s of animated views), occasionally one of the fade-in-views will animate exactly like one of the translation views.

It is not seem deterministic. With my app, it takes me 1-2 minutes of heavy usage before it seems to manifest.
Video where you can see it happen: https://imgur.com/a/5HKTHZY. Right before the end, at about "3:30" on the dial (right side, below halfway) you can see the small colored circle bounce around and end up in the wrong location, instead of just fading in.

Steps to reproduce

@MatiPl01 said in this discussion thread #6756 the team was aware of the issue and working on a solution. Based on his comments, I assume that it's creating a destroy a lot of animated views with different animations.

I have attempted to a create small repo to reproduce the problem, but have not had success yet.

Snack or a link to a repository

Still working on it.

Reanimated version

3.16.6

React Native version

0.76.5

Platforms

Android, iOS

JavaScript runtime

Hermes

Workflow

React Native

Architecture

Fabric (New Architecture)

Build type

Debug app & dev bundle

Device

Android emulator

Device model

Pixel 7 Pro

Acknowledgements

Yes

[github-actions]

Hey! 👋

The issue doesn't seem to contain a minimal reproduction.

Could you provide a snack or a link to a GitHub repository under your username that reproduces the problem?

[dcorbin]

I reported this issue here so that I can track it even though the team seems to know about it. I will continue trying to create the problem in a small sample repo.

[MatiPl01]

I reported this issue here so that I can track it even though the team seems to know about it. I will continue trying to create the problem in a small sample repo.

I think you won't succeed in creating a repro as this behavior is related to React's view recycling and you won't be able to create a deterministic example. It's fine to leave this issue open without a repro.

[dcorbin]

I was expecting determinism, but I was hoping for something that could reproduce it in a minute or two. And of course trying to be good user-citizen :)