React Native
A comprehensive walkthrough of React Native Testing Library with Jest, covering renderHook for custom hooks, userEvent for realistic interactions, the full query API, async utilities, and accessibility-first testing patterns. React Native Testing Library (RNTL) has matured into the standard way to test React Native components and hooks. Paired with
React Native
Snapshot testing in React Native can catch unintended UI regressions, but done wrong it becomes a rubber-stamp exercise. This post covers when snapshots add value, how to write focused inline snapshots, and patterns that keep your snapshot suite meaningful over time. Snapshot testing is one of the most misused
React Native
Testing navigation in React Native requires mocking React Navigation's hooks and prop injection, verifying that screens navigate correctly in response to user actions, and testing deep links and complex stack flows. This post covers the full range of navigation testing patterns. Navigation is one of the trickiest parts
React Native
A deep dive into mocking native modules in React Native Jest tests, covering inline jest.mock patterns, the mocks directory, NativeEventEmitter simulation, and writing robust manual mocks for complex native APIs like Camera, Location, and Bluetooth. Native modules are the bridge between JavaScript and platform APIs like the camera, GPS,
Expo
Expo adds a layer of abstraction over React Native that requires specific testing strategies. The jest-expo preset handles most of the configuration complexity, but mocking expo-* modules, testing Expo Router's file-based navigation, and connecting Detox to the bare workflow each have their own patterns. This guide
React Native
@testing-library/react-native brings the same user-centric testing philosophy to mobile that Testing Library brought to the web. This guide covers component rendering, custom hook testing with renderHook, mocking stubborn native modules, taming async state with waitFor and findBy, and the act() gotchas that trip up even experienced
Detox
Detox is a gray-box E2E testing framework for React Native that eliminates flakiness by synchronizing with the app's JavaScript thread and native animation system rather than relying on sleep timers. This guide walks through complete iOS and Android setup, the synchronization model that makes Detox reliable, and
Test Automation
NativeWind v4 brings Tailwind CSS utility classes to React Native using a compiler that converts className strings into StyleSheet-compatible styles. Testing NativeWind components requires understanding what the compiler produces and how to assert it. This guide covers NativeWind v4 testing: className-based assertions, dark mode switching, responsive breakpoints, and
Test Automation
React Native's New Architecture — Fabric renderer, JSI (JavaScript Interface), and TurboModules — changes how native modules communicate with JavaScript. For testing, the key impact is that TurboModules use synchronous JSI calls instead of asynchronous bridge messages, and Fabric renders components differently from the legacy renderer. This guide covers testing
Test Automation
Expo Router brings file-based routing to React Native with full TypeScript support. Each file in your app/ directory maps to a route, layouts wrap segments, and tabs and modals are first-class patterns. Testing all of this requires understanding what Expo Router provides and what you need to verify
Testing
Maestro takes a different approach to mobile UI testing than most frameworks. Instead of writing JavaScript or Python test code, you define flows in YAML. Instead of requiring build-time instrumentation, it works with any app — debug builds, release builds, or even apps you don't have the source
Testing
Running mobile E2E tests locally is one thing. Getting them to run reliably in CI is another problem entirely. You're dealing with emulators that need time to boot, builds that need to be cached, iOS simulators that require macOS runners, and Android emulators that need KVM acceleration or