Toggle the new Android prop diffing mechanism for components (0.78.0)

[fabOnReact]

Summary:

The PR for branch 0.78.2 is #68.

The feature flag is supported in react-native 0.79 and requires cherrypicking the following commits from David Vacca:

• Implement prop diffing for accessibility props in View #48833
• Implement prop diffing for transform props in View #48832
• Implement prop diffing for border props in View #48831
• Implement prop diffing for event props in View #48830
• Implement prop diffing for basic props in View #48829

Enables feature flag enablePropsUpdateReconciliationAndroid to fix https://app.asana.com/1/236888843494340/project/1199705967702853/task/1209601835367711?focus=true

More info at facebook#45551 and https://github.com/discord/react-native/blob/e0702345591cb461e196aabd8be0bf51839a2df3/packages/react-native/scripts/featureflags/README.md

Changelog:

This diffs toggles the new Android prop diffing mechanism for components

Test Plan:

Regressions from previous PR #61 are fixed by cherry picking the above commits.

Branch 0.78:

Before enabling the feature flag	After enabling the feature flag

After cherry-picking commits:

Discord:

Before cherry-pick	After cherry-pick
20250527_202152.mp4	20250527_202926.mp4

---

• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1210629848047854

[fabOnReact]

@hannomargelo

There are some changes that are part of https://github.com/discord/react-native/pull/65/files, which trigger some changes in the feature flags after running yarn featureflags --update. Should I look into that tomorrow? Or I start working on the next task? Thanks.

[ghost]

Hm, actually i don't think we use yarn featureflags --update in this fork, but manually pick over the changes we need (ie cherry pick the commit where they added the feature flag)

Would that work for you as well, or did you want to introduce a new feature flag?

I am not sure what all of those changes are, maybe its okay to add them

[ghost]

For this bug here:

20250527_202152.mp4

How did you get into that state?

[fabOnReact]

@hannomargelo
Regarding #69 (comment)

The issue is introduced by enabling the feature flag enablePropsUpdateReconciliationAndroid and running yarn feature-flags --update in the react-native fork or discord app. It is a react-native issue from 0.78 and it is fixed in 0.79.

I cherry picked the changes from 0.79 in this branch and tested the fix in both discord and the react-native fork:

• Implement prop diffing for accessibility props in View #48833
• Implement prop diffing for transform props in View #48832
• Implement prop diffing for border props in View #48831
• Implement prop diffing for event props in View #48830
• Implement prop diffing for basic props in View #48829

Regarding #69 (comment).
Thanks. I'll update the PR tomorrow and follow your approach from PR 65 to hardcode the feature flags (instead of running yarn feature-flags --update).

[fabOnReact]

@joemun Ready to merge. Thanks

[Android] View Manager prop setters called for unchanged values https://app.asana.com/1/236888843494340/project/1199705967702853/task/1209601835367711?focus=true

[joemun]

@hannomargelo I've been off new arch work for a while, and am just getting back to it. Hanno, could you take a look at this? not sure what the current state of everything is and whether enabling this behavior makes sense. thanks

[ghost]

Yeah i think this change makes sense. I am OOO until tuesday as well (as there is a public holiday coming up).
I will test this change in the discord app on tuesday and update here then!

[ghost]

When testing this change i noticed this bug where the previously pressed channel would look like this:

Would need to spend more time double checking i think for now its fine just rolling out the one feature flag active