Bringing React Native to the next billion devices

Hargett frames “learn once, write anywhere” around sharing React concepts and JavaScript code across platforms. He says React Native can target Windows desktops, Xbox One, Android TV, web, iOS, and mobile, and argues that Windows reach is about desktop users, not Windows Phone.

Sharing JavaScript does not automatically share fixes for native bugs, such as Yoga node leaks, view management races, and errors that fail to reject promises. Hargett says platform forks can miss fixes and have uneven native test coverage, making those issues harder to diagnose and maintain.

Hargett proposes sharing roughly 30% of native code, including the JavaScript bridge, bundle loader, executor, and core modules, while keeping UI and threading platform-specific. With compatible UI toolkits, he suggests as much as 80% of native code could be shared. He points to Facebook’s cross-platform C++ work and .NET Standard libraries as possible building blocks.

Hargett describes how React Native for Windows shares more than 60% of its code across Windows 7, 8, and 10 using shared projects. His .NET Standard core library includes the bridge, bundle loader, promises, timers, and tests, while separate interfaces let platforms provide their own implementations. Keeping the core free of GUI dependencies also makes a headless .NET Core example possible.

Hargett argues that sharing native code can improve both reach and stability by letting platforms receive bug fixes together. He says packaging and dependency inversion can reduce platform fragmentation and reliance on Git submodules. He plans to develop the approach further with Facebook contributors through an RFC.