React developers in a wild world of native apps

Web developers can work in a browser, while mobile development calls for testing on iOS and Android simulators or real devices. Milica cautions that simulators may miss hardware issues, so she recommends testing on real devices throughout development. React Native styles use JavaScript objects and camel case; Flexbox remains available, with column as the default direction. She also recommends styled-components for CSS syntax, dynamic styling, and theming.

Native apps use screens and navigation patterns such as tabs and stacks, rather than browser pages and URL history. Milica describes a stack as a deck: a new screen goes on top, and going back removes it. She also explains that apps move between foreground, background, and inactive states, and points to React Native’s AppState API for tracking those changes.

React Native provides the Platform module for small platform-specific changes and .ios or .android file extensions for separate components. Mobile apps also need to handle permissions for features such as the camera, since users may grant or deny access. Because mobile connections can be slow, unreliable, or absent, Milica recommends clear offline feedback and mentions NetInfo for checking connectivity and network type.

React Native Web can bring a mobile app to the browser, though Milica says the port may need substantial UI changes. Teams can also share platform-independent logic and components between web and mobile. She describes Yarn Workspaces and Lerna as options for organizing shared packages in a monorepo, and recommends Jest with React Native Testing Library or Test Renderer for tests.

Chrome Developer Tools can debug JavaScript, while Flipper offers a desktop interface for inspecting React Native, iOS, and Android apps. Its plugins can show logs, crash reports, network requests, performance, cached images, and native layouts. Deployment follows app store processes: Apple validation can take a few days, and TestFlight supports beta testing. Milica also describes CodePush through App Center as a way to deliver some updates without waiting for a new build.