36033bd0ed
Summary: **Summary** The RN transformer currently relies on the enviroment providing babelHelpers and regeneratorRuntime as globals by using 'babel-external-helpers'. This wasn't really a problem before since helpers were stable and we could maintain our copy easily but it seems like there are more now with babel 7 and it makes sense to include only those used by the app. This is exactly what babel/transform-runtime does. It will alias all helpers and calls to regeneratorRuntime to files in the babel/runtime package. This will solve issues like this https://github.com/facebook/react-native/issues/20150 caused by missing babelHelpers. This solution also avoids bloating babelHelpers to fix OSS issues like the one linked before. **Test plan** - Updated tests so they all pass. - Tested that it actually works by applying the changes locally in an RN app. - Added a test for async functions, to make sure regenerator is aliased properly and doesn't depend on the global. - Made sure require-test.js still fails if the require implementation contains babel helpers (by adding an empty class in the file). Pull Request resolved: https://github.com/facebook/metro/pull/198 Reviewed By: mjesun Differential Revision: D8833903 Pulled By: rafeca fbshipit-source-id: 7081f769f288ab358ba89ae8ee72a513bb12e225
React Native · 
Learn once, write anywhere: Build mobile apps with React.
See the official React Native website for an introduction to React Native.
Requirements
Supported target operating systems are >= Android 4.1 (API 16) and >= iOS 9.0. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS by default (tools like Expo can be used to get around this).
Building your first React Native app
Follow the Getting Started guide. The recommended way to install React Native depends on your project. Here you can find short guides for the most common scenarios:
How React Native works
React Native lets you build mobile apps using JavaScript. It uses the same design as React, letting you compose a rich mobile UI from declarative components.
With React Native, you don't build a "mobile web app", an "HTML5 app", or a "hybrid app". You build a real mobile app that's indistinguishable from an app built using Objective-C, Java, Kotlin, or Swift. React Native uses the same fundamental UI building blocks as regular iOS and Android apps. You just put those building blocks together using JavaScript and React.
React Native lets you build your app faster. Instead of recompiling, you can reload your app instantly. With hot reloading, you can even run new code while retaining your application state.
React Native combines smoothly with components written in Objective-C, Java, Kotlin, or Swift. It's simple to drop down to native code if you need to optimize a few aspects of your application. It's also easy to build part of your app in React Native, and part of your app using native code directly - that's how the Facebook app works.
The focus of React Native is on developer efficiency across all the platforms you care about - learn once, write anywhere. Facebook uses React Native in multiple production apps and will continue investing in React Native.
Full documentation
The full documentation for React Native can be found on our website. The source for the React Native documentation and website is hosted on a separate repo, https://github.com/facebook/react-native-website.
The React Native documentation only discusses the components, APIs, and topics specific to React Native (React on iOS and Android). For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
Join the React Native community
- Website: https://facebook.github.io/react-native
- Twitter: https://twitter.com/reactnative
- Discussion: https://discuss.reactjs.org/
See the CONTRIBUTING file for how to help out.
License
React Native is MIT licensed, as found in the LICENSE file.
React Native documentation is Creative Commons licensed, as found in the LICENSE-docs file.