Who contributed to Meta on May 8, 2026?

1 developer shipped this update, including ahnpnl.

What were the notable Meta updates?

[Fiber] track stylesheet preloads when explicitly preloaded, Remove unused websocketProxyURL property (#56722), and Cleanup useLISAlgorithmInDifferentiator flag (#56715).

REACT SHIPS STYLESHEET PRELOAD FIX, JEST 30.4 REWRITES RUNTIME FOR ESM STABILITY

By RepoJournal · Filed 06:03 UTC on May 8, 2026 · About Meta

1 person shipped this

ahnpnl @ahnpnl 2 cited

React's Fiber engine now correctly tracks explicitly preloaded stylesheets, eliminating unnecessary commit suspensions that plagued stylesheet-heavy apps, while Jest's massive 30.4 release stabilizes ESM support and adds Temporal API mocking for Node 26.

The stylesheet preload fix [1] lands in React as a critical stabilization — previously preloaded stylesheets would force Fiber to re-request the same resource, delaying commits or triggering fallbacks even when the asset was already loading. This matters for any app using resource hints in the document head. On the React Native side, the team is aggressively cleaning house: removing the deprecated websocketProxyURL property [2], excising the unused LIS differentiator experiment flag [3], and completing the z-index deprecation [4]. A new RFC [5] proposes replacing the ambiguous 'unspecified' value with 'auto' in ColorScheme APIs, aligning with CSS standards. Meanwhile, Jest 30.4 [6] lands a complete runtime rewrite that unblocks native ESM stabilization — you can now `require(esm)` on Node 24.9+ (still experimental), React 19 snapshots finally work correctly in pretty-format, and fake timers now mock the Temporal API for Node 26 compatibility. Two critical Jest bugs got fixed: coverage reports now work properly with the `projects` option [7], and global coverage thresholds apply correctly to unmatched pattern files [8].

Action items

→ Upgrade React to pick up stylesheet preload tracking — test apps with resource hints in strict mode facebook/react [plan]
→ Upgrade Jest to 30.4 if you're on Node 26 or using Temporal mocking — snapshot tests will improve facebook/jest [plan]
→ Audit React Native code for deprecated zIndex and websocketProxyURL usage before next major facebook/react-native [monitor]

References

[1] [Fiber] track stylesheet preloads when explicitly preloaded ↗ facebook/react
[2] Remove unused websocketProxyURL property (#56722) facebook/react-native
[3] Cleanup useLISAlgorithmInDifferentiator flag (#56715) facebook/react-native
[4] Remove setViewZIndex and associated state from BaseViewManager (#56717) facebook/react-native
[5] Add 'auto' to ColorSchemeOverride, deprecate 'unspecified' facebook/react-native
[6] v30.4.0 ↗ facebook/jest
[7] fix: make coverage work when using `projects` option ↗ facebook/jest
[8] fix(jest-reporters): apply global coverage threshold to unmatched pattern files ↗ facebook/jest

Quick answers

What shipped in Meta on May 8, 2026?: React's Fiber engine now correctly tracks explicitly preloaded stylesheets, eliminating unnecessary commit suspensions that plagued stylesheet-heavy apps, while Jest's massive 30.4 release stabilizes ESM support and adds Temporal API mocking for Node 26. In total, 22 commits, 6 pull requests, and 2 releases landed.
Who contributed to Meta on May 8, 2026?: 1 developer shipped this update, including ahnpnl.
What were the notable Meta updates?: [Fiber] track stylesheet preloads when explicitly preloaded, Remove unused websocketProxyURL property (#56722), and Cleanup useLISAlgorithmInDifferentiator flag (#56715).

REACT FIBER FIXES SINGLETON PROPERTY BLEED, REACT NATIVE STRIPS DEAD CODE

React plugged a critical Fiber bug where singleton cleanup was nuking third-party attributes, while React Native dropped unused timing code from iOS binaries.

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Meta 1 day ago

REACT DEVTOOLS BRIDGE HARDENS AGAINST RECONNECTS AND CORRUPTION

React's DevTools layer just got bulletproof: hoxyq landed four interconnected patches that eliminate silent state corruption, validate invariants before mutation, and handle extension reconnects with message buffering and handshakes.

javascript 22 shipped 2-min read

Meta 2 days ago

REACT SERVER DOM TURBOPACK GETS DYNAMIC CHUNK MERGING

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React 19 Cuts Server Component Decoding Time, React Native Fixes requestIdleCallback Regression

React shipped performance wins across 19.0.8 and 19.1.9 while React Native patched a critical timeout bug that broke requestIdleCallback tasks.

javascript 22 shipped 2-min read

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