`useOnyx` subscription to collection member key doesn't update correctly after `Onyx.clear()`

[mountiny]

Problem Statement

When a collection is cleared using Onyx.clear() (e.g., clearing all report_ keys), useOnyx subscriptions to individual collection member keys (e.g., report_123) fail to recalculate and return the correct/newest value. The subscription value remains stale.

Expected Behaviour

After Onyx.clear() is called, all useOnyx hooks subscribed to collection member keys should be notified and re-render with the updated (cleared) values.

Actual Behavior

useOnyx works correctly with regular key subscriptions after Onyx.clear(), but not with collection member key subscriptions. The subscriber receives stale data instead of being properly notified of the change.

Root Cause Analysis

During Onyx.clear(), collection data is being notified through a different code path. Faulty logic is clearing the collection data from the cache before it can be used during the notify logic execution, which causes the useOnyx subscriber to not be properly notified of the change.

Reproduction

A failing unit test demonstrating this issue is available in:

• PR with failing test: [WIP] Fix useOnyx subscription to collection member key after Onyx.clear() react-native-onyx#722

Related

• Discovered in: Fix opening an expense report from Reports page shows the same report when open Inbox #79436

Issue Owner

Current Issue Owner: @fabioh8010

[melvin-bot]

Triggered auto assignment to @kadiealexander (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details. Please add this bug to a GH project, as outlined in the SO.

[fabioh8010]

Updates:

• Tests are passing on both Onyx and E/App repos.
• I did some manual testing in E/App with signing out and switching accounts (both call Onyx.clear) and I didn't notice problems, I assume we can now test these changes in Fix opening an expense report from Reports page shows the same report when open Inbox #79436.