React Native Harness, Next.js 16 Beta & Remix v3
Featuring
This week’s livestream brought a packed agenda of updates across the React and React Native ecosystem. As always, the discussion was based on insights from the This Week in React newsletter. Here’s a summary of the key topics and announcements.
React Native Harness: fast and real testing
The highlight of the stream was a conversation with Szymon Chmal, author of React Native Harness a new testing solution that bridges the long-standing gap between fast unit tests and real-world end-to-end scenarios.
Testing in React Native has traditionally meant choosing between speed and realism:
- Fast: Jest-based unit and component tests.
- Real: Full E2E tests covering complete user flows.
Native modules and spec compliance often didn’t fit neatly into either category. React Native Harness introduces a middle ground that delivers both.
Why it matters
- Runs tests directly on device or emulator.
- Uses familiar Jest syntax.
- No mocks by default.
Harness enables native testing that’s both fast and real, making it practical again for complex native integrations.
It’s already in action in react-native-mmkv, where real-device tests validate native functionality.
Read the full article here.
Framework updates
Next.js 16 Beta
Released just before Next.js Conf, the Next.js 16 Beta marks a major step forward for the framework:
- Turbopack is now stable
- React Compiler support is stable (opt-in)
- React 19.2 adds
<Activity>, View Transitions, anduseEffectEvent - Persistent caching in dev mode for faster reloads
Read more on the Next.js blog.
Remix v3 “pre-drop”
Another big announcement this week came from the Remix team: Remix v3 is no longer built on React.
In a detailed three-hour presentation, Ryan Florence and Michael Jackson outlined a new architecture built on web platform primitives.
Key highlights include:
- JSX remains, but re-renders are manual.
- A composable event system exists outside components.
- The new
<Frame>component reintroduces a Suspense-like flow. - The framework is now focused fully on web-native primitives.
Watch the full presentation on YouTube.
React Alicante 2025 recap
React Alicante 2025 delivered a strong lineup of speakers, engaging talks, and a vibrant community atmosphere.
For a comprehensive summary of the event, check out Kate Marshalkina’s recap.
Other highlights
- Expo is introducing first-class CSS and Tailwind support, as announced by Evan Bacon.
- This represents a major step toward consistent styling across React Native and web.
- React Native Screens will soon include Native Split View support, enabling multi-pane layouts powered by native navigation primitives. See the announcement.
- React Conf 2025 brought several React Native updates, summarized in our latest newsletter.
- The latest episode of the React Universe on Air podcast features the NFL team, exploring how React Native powers large-scale applications. Watch on YouTube.
- Additional Callstack-related highlights from the newsletter include:
Final thoughts
This week’s stream covered a broad spectrum, from framework breakthroughs to new tooling for more realistic testing in React Native.
Special thanks to Szymon Chmal, Kewin Wereszczyński, and theThis Week in React team: Sebastien Lorber, Kacper Kapuściak, and Krzysztof Piaskowy for curating yet another rich edition of the newsletter.
