react/scripts/flow/xplat.js
Pieter De Baets 151e75a128
[Fabric] Pass children when cloning (#27458)
## Summary

Currently when cloning nodes in Fabric, we reset a node's children on
each clone, and then repeatedly call appendChild to restore the previous
list of children (even if it was quasi-identical to before). This causes
unnecessary invalidation of the layout state in Fabric's ShadowNode data
(which in turn may require additional yoga clones) and extra JSI calls.

This PR adds a feature flag to pass in the children as part of the clone
call, so Fabric always has a complete view of the node that's being
mutated.

This feature flag requires matching changes in the react-native repo:
https://github.com/facebook/react-native/pull/39817

## How did you test this change?

Unit test added demonstrates the new behaviour 

```
yarn test -r www-modern ReactFabric-test
yarn test ReactFabric-test.internal
```

Tested a manual sync into React Native and verified core surfaces render
correctly.
2023-10-10 15:11:26 +01:00

17 lines
570 B
JavaScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
declare module 'ReactNativeInternalFeatureFlags' {
declare export var enableUseRefAccessWarning: boolean;
declare export var enableDeferRootSchedulingToMicrotask: boolean;
declare export var alwaysThrottleRetries: boolean;
declare export var useMicrotasksForSchedulingInFabric: boolean;
declare export var passChildrenWhenCloningPersistedNodes: boolean;
}