Who contributed to Meta on August 22, 2026?

5 developers shipped this update, including Dawid Małecki, Mohammad Dahmardeh, Mad Dinh, Christian Falch, and Simen Bekkhus.

What were the notable Meta updates?

perf(jest-resolve): make the warm default-resolver path about 3x cheaper, perf(jest-haste-map): cache the watchman socket path and drop the version probe (#16386), and refactor(jest-runtime): remove dead accessors and collapse duplicated module-loading shapes.

JEST SPEEDS UP AND RN PATCHES ANDROID CRASHES

By RepoJournal · Filed 06:58 UTC on August 22, 2026 · About Meta

5 people shipped this

Simen Bekkhus @SimenB 4 cited

Mad Dinh @dennytosp 2 cited

Dawid Małecki @coado 1 cited

Mohammad Dahmardeh @neutronm 1 cited

Christian Falch @chrfalch 1 cited

Overnight, Jest's resolver got 3x faster on warm paths and React Native fixed a pair of Android ViewManager crashers.

Jest is quietly getting faster where it hurts most: SimenB slashed the warm default-resolver path about 3x cheaper [1] by reusing an `unrs-resolver` factory per options shape, and `jest-haste-map` now caches the watchman socket path and drops the version probe [2] to cut startup overhead. That's on top of a `jest-runtime` cleanup [3] that removes dead accessors and collapses duplicated module-loading shapes, exposing one latent bug along the way. For snapshot-heavy suites, `jest-snapshot` now lazily loads babel, semver, and synckit [4], so `@swc/jest` and `ts-jest` users stop paying 162 `@babel/*` modules per worker when they have zero snapshots. Meanwhile, React Native moves on two crash fronts: Android ViewManagers implementing `DimensionValue` props [5] and nullable float props [6] both threw `RuntimeException: Unrecognized type` at startup, now fixed. iOS gets correct dotted and dashed outline rendering without border radii [7], fixing issue #57841. The SPM manifests now derive from shared name constants [8] to avoid clashing with built-in packages, and an umbrella header for `react/renderer/uimanager` [9] classifies the module as public. As SimenB notes, the resolver change is "a ~5µs NAPI call that dominated the warm path" [1]. Overall: upgrade both repos when you can, but prioritize the Android crash fixes if you ship Fabric components.

Action items

→ Review Jest master for the resolver and haste-map perf wins, especially if you use Watchman facebook/jest [plan]
→ Pull the DimensionValue and nullable float ViewManager fixes if you ship Fabric components on Android facebook/react-native [immediate]
→ Test dotted/dashed outline rendering on iOS views without border radii facebook/react-native [monitor]

References

[1] perf(jest-resolve): make the warm default-resolver path about 3x cheaper ↗ facebook/jest
[2] perf(jest-haste-map): cache the watchman socket path and drop the version probe (#16386) facebook/jest
[3] refactor(jest-runtime): remove dead accessors and collapse duplicated module-loading shapes ↗ facebook/jest
[4] perf(jest-snapshot): load babel, semver and synckit lazily ↗ facebook/jest
[5] Fix DimensionValue props crashing ViewManagers on Android (#58039) facebook/react-native
[6] Fix nullable float props crashing ViewManagers on Android (#58038) facebook/react-native
[7] fix: render dotted and dashed outlines on iOS views without border radii (#58028) facebook/react-native
[8] Derive the generated SPM manifests from shared name constants (#58035) facebook/react-native
[9] Add umbrella for `react/renderer/uimanager` subtree (#58025) facebook/react-native

Quick answers

What shipped in Meta on August 22, 2026?: Overnight, Jest's resolver got 3x faster on warm paths and React Native fixed a pair of Android ViewManager crashers. In total, 20 commits and 9 pull requests landed.
Who contributed to Meta on August 22, 2026?: 5 developers shipped this update, including Dawid Małecki, Mohammad Dahmardeh, Mad Dinh, Christian Falch, and Simen Bekkhus.
What were the notable Meta updates?: perf(jest-resolve): make the warm default-resolver path about 3x cheaper, perf(jest-haste-map): cache the watchman socket path and drop the version probe (#16386), and refactor(jest-runtime): remove dead accessors and collapse duplicated module-loading shapes.

JEST RUNTIME OVERHEAD SLAIN AS RN SHORES UP API BORDERS

Jest just deleted a pile of hidden per-require work, and React Native is locking down its private components with strict API guards.

javascript 14 shipped

Meta Aug 20

React Fragments leak listeners as refs re-attach

A subtle React bug is piling up event listeners when Fragment refs re-attach with a fresh identity on each render.

javascript 20 shipped

Meta Aug 19

Jest's resolver gets a major speedup and Node-compatible module handling

SimenB's latest PRs cut repeated work on the resolution hot path and fix several long-standing module system bugs, making Jest faster and more accurate than ever.

javascript 34 shipped

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React Native kills the ArrayBuffer copy tax

React Native just made TurboModule ArrayBuffer crossing zero-copy on both iOS and Android, and the borrow contract is now enforced in Java.

javascript 15 shipped

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