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Rubén Norte
325072575a
Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/37553 ## Context I added some getters in EventTarget/EventEmitter to access the React instance handle for a given shadow node/shadow node family in https://github.com/facebook/react-native/commit/43864a1d6025bfc4483dded115d51f7613018199 (D44022477), so I could implement DOM traversal methods easily. I wanted to reuse that method to implement `MutationObserver` and `IntersectionObserver`, but unfortunately `EventEmitter`/`EventTarget` only allow access to the instance handle as long as the shadow node is mounted. That makes sense for events, but not for this use case, as with `MutationObserver` we intentionally want to have access to unmounted nodes when creating the list of `addedNodes` and `removedNodes` for the `MutationRecord` (depending on when exactly we generate this list, either `addedNodes` or `removedNodes` wouldn't be mounted). ## Changes This reverts my original change and adds a new field in `ShadowNodeFamily` to provide access to the `InstanceHandle` at any point (even if the node isn't mounted). This provides the same guarantees as the original method, keeping weak references to the handles to avoid memory leaks. Changelog: [internal] Reviewed By: sammy-SC Differential Revision: D46149084 fbshipit-source-id: f76abae50134a5d55a98cab42eebeb62084024f9