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Delete obsolete MountingIntermediateCommits-itest.js#56628

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fkgozali wants to merge 1 commit into
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fkgozali:export-D102661539
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Delete obsolete MountingIntermediateCommits-itest.js#56628
fkgozali wants to merge 1 commit into
react:mainfrom
fkgozali:export-D102661539

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Summary:
This test file contains a single it.skip test guarded by the comment "Enable once synchronous C++ state updates are re-introduced." That feature was deleted entirely (not just disabled) since 2025-07-15, with the reason: *"The current design of enableSynchronousStateUpdates is not correct and breaks <Modal /> on Android. let's delete it.

Findings: A scan of packages/react-native/src/private/featureflags, scripts/featureflags, and ReactCommon/react/featureflags returns no replacement flag for synchronous C++ state updates. The enableSynchronousStateUpdates flag was removed from every layer (JS config, C++, Android Kotlin/JNI, iOS overrides, MC schemas) and the guarded code path in EventQueue.cpp was deleted as well.

Empirical confirmation: Removed the it.skip and ran the test 10x via stress runs. All 10 runs failed deterministically. The test is asserting the presence of the bug — i.e., that an intermediate state mutation leaks through when a UI-thread commit pulls transactions from an in-flight JS commit. Without the synchronous-state-updates codepath, that leak no longer occurs, so the test's expected log never matches the actual output:

Expected: [Update ScrollView, Update intermediate-state-should-not-be-visible, Update view]
Actual: [Update view, Update ScrollView]

The test cannot be un-skipped (the bug it documents is no longer reproducible), and rewriting the assertion would defeat the purpose of the test. Deleting it.

Changelog: [Internal]

Differential Revision: D102661539

Summary:
This test file contains a single `it.skip` test guarded by the comment "Enable once synchronous C++ state updates are re-introduced." That feature was deleted entirely (not just disabled) since 2025-07-15, with the reason: *"The current design of enableSynchronousStateUpdates is not correct and breaks `<Modal />` on Android. let's delete it.

Findings: A scan of `packages/react-native/src/private/featureflags`, `scripts/featureflags`, and `ReactCommon/react/featureflags` returns no replacement flag for synchronous C++ state updates. The `enableSynchronousStateUpdates` flag was removed from every layer (JS config, C++, Android Kotlin/JNI, iOS overrides, MC schemas) and the guarded code path in `EventQueue.cpp` was deleted as well.

Empirical confirmation: Removed the `it.skip` and ran the test 10x via stress runs. All 10 runs failed deterministically. The test is asserting the *presence* of the bug — i.e., that an intermediate state mutation leaks through when a UI-thread commit pulls transactions from an in-flight JS commit. Without the synchronous-state-updates codepath, that leak no longer occurs, so the test's expected log never matches the actual output:

  Expected: [Update ScrollView, Update intermediate-state-should-not-be-visible, Update view]
  Actual:   [Update view, Update ScrollView]

The test cannot be un-skipped (the bug it documents is no longer reproducible), and rewriting the assertion would defeat the purpose of the test. Deleting it.

Changelog: [Internal]

Differential Revision: D102661539
@meta-codesync

meta-codesync Bot commented Apr 27, 2026

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@fkgozali has exported this pull request. If you are a Meta employee, you can view the originating Diff in D102661539.

@meta-cla meta-cla Bot added the CLA Signed This label is managed by the Facebook bot. Authors need to sign the CLA before a PR can be reviewed. label Apr 27, 2026
@meta-codesync meta-codesync Bot closed this in 6a17c21 Apr 28, 2026
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This pull request was successfully merged by @fkgozali in 6a17c21

When will my fix make it into a release? | How to file a pick request?

@react-native-bot react-native-bot added the Merged This PR has been merged. label Apr 28, 2026
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