Szymon Chmal
@chmal.it
Dev Lead / Senior React Native Developer x Callstack | Microsoft MVP | Speaker | GDG Toruń Leader
Expect it to be included in the next Harness release! With it, I can leverage Jest's infrastructure, such as built-in reporters, and potentially support running the same test suite in parallel across multiple devices.
Huge thanks to @thymikee.bsky.social for pitching the idea at React Conf!
Huge thanks to @thymikee.bsky.social for pitching the idea at React Conf!
October 17, 2025 at 7:32 PM
Expect it to be included in the next Harness release! With it, I can leverage Jest's infrastructure, such as built-in reporters, and potentially support running the same test suite in parallel across multiple devices.
Huge thanks to @thymikee.bsky.social for pitching the idea at React Conf!
Huge thanks to @thymikee.bsky.social for pitching the idea at React Conf!
Want to learn more? See the following link: clstk.com/3Ldc3Kt
React Native Harness: Deep Dive | Callstack
Discover how React Native Harness enables fast, reliable testing of native modules directly on real devices. Learn how to write Jest-style tests, integrate them into CI/CD, and catch up on the latest ...
clstk.com
October 16, 2025 at 9:27 AM
Want to learn more? See the following link: clstk.com/3Ldc3Kt
Learn more from our article: clstk.com/4oqiIj3
React Native Harness: Fast, Real-Device Testing for Native Modules
React Native Harness lets you run Jest-style tests directly on devices and emulators. Fast, reliable, and CI-ready. It’s the easiest way to validate native behavior in React Native.
clstk.com
October 15, 2025 at 1:59 PM
Learn more from our article: clstk.com/4oqiIj3
Harness is Open Source! Check out our Github and make sure to star it!
github.com/callstackinc...
github.com/callstackinc...
GitHub - callstackincubator/react-native-harness: Harness brings Jest-style tests to real native environments so you can test TurboModules like you would test your React Native app: with JavaScript.
Harness brings Jest-style tests to real native environments so you can test TurboModules like you would test your React Native app: with JavaScript. - callstackincubator/react-native-harness
github.com
October 15, 2025 at 1:59 PM
Harness is Open Source! Check out our Github and make sure to star it!
github.com/callstackinc...
github.com/callstackinc...
Designed for library authors and teams building native integrations.
It is cross-platform, works on CI/CD and made to test real native behavior with a familiar workflow.
It is cross-platform, works on CI/CD and made to test real native behavior with a familiar workflow.
October 15, 2025 at 1:59 PM
Designed for library authors and teams building native integrations.
It is cross-platform, works on CI/CD and made to test real native behavior with a familiar workflow.
It is cross-platform, works on CI/CD and made to test real native behavior with a familiar workflow.
Harness runs wherever Metro runs, starting with iOS and Android. It's built to be portable, making support for new platforms straightforward.
As proof, we're also bringing support for VegaOS.
As proof, we're also bringing support for VegaOS.
October 15, 2025 at 1:59 PM
Harness runs wherever Metro runs, starting with iOS and Android. It's built to be portable, making support for new platforms straightforward.
As proof, we're also bringing support for VegaOS.
As proof, we're also bringing support for VegaOS.
Harness runs tests in a real React Native runtime.
Unlike Jest, it doesn't rely on mocks and unlike Detox or Maestro, it focuses on testing native code directly, not automating UI flows.
Unlike Jest, it doesn't rely on mocks and unlike Detox or Maestro, it focuses on testing native code directly, not automating UI flows.
October 15, 2025 at 1:59 PM
Harness runs tests in a real React Native runtime.
Unlike Jest, it doesn't rely on mocks and unlike Detox or Maestro, it focuses on testing native code directly, not automating UI flows.
Unlike Jest, it doesn't rely on mocks and unlike Detox or Maestro, it focuses on testing native code directly, not automating UI flows.
I scored a little discount just for you! Use promo code Chmal15 at checkout to get 15% off. Pretty sweet, right?
August 4, 2025 at 4:25 PM
I scored a little discount just for you! Use promo code Chmal15 at checkout to get 15% off. Pretty sweet, right?
What are you waiting for?
Install Rozenite, fall in love, and drop your own star ⭐
github.com/callstackinc...
Install Rozenite, fall in love, and drop your own star ⭐
github.com/callstackinc...
GitHub - callstackincubator/rozenite: A comprehensive toolkit for creating, developing, and integrating custom plugins into React Native DevTools.
A comprehensive toolkit for creating, developing, and integrating custom plugins into React Native DevTools. - callstackincubator/rozenite
github.com
August 1, 2025 at 4:30 PM
What are you waiting for?
Install Rozenite, fall in love, and drop your own star ⭐
github.com/callstackinc...
Install Rozenite, fall in love, and drop your own star ⭐
github.com/callstackinc...
Next stop: WebSocket interception - just like Chrome DevTools! You'll be able to see every message going in and out of the device.
What do you think - super useful or not really? 🤔
What do you think - super useful or not really? 🤔
August 1, 2025 at 1:03 PM
Next stop: WebSocket interception - just like Chrome DevTools! You'll be able to see every message going in and out of the device.
What do you think - super useful or not really? 🤔
What do you think - super useful or not really? 🤔
You can learn more about the tool and how to use it today in the article below:
www.callstack.com/blog/introdu...
www.callstack.com/blog/introdu...
Introducing Rozenite: A Plugin Framework for React Native DevTools
Build custom debugging panels inside React Native DevTools with Rozenite: a modular, TypeScript-ready plugin framework with full device-scoped support.
www.callstack.com
July 28, 2025 at 7:20 PM
You can learn more about the tool and how to use it today in the article below:
www.callstack.com/blog/introdu...
www.callstack.com/blog/introdu...