Moti Zilberman
9ba3bc99e4
Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/42144 D51895785 changed several CMake libraries from shared to static, including `jsinspector`. This happens to be semantically incorrect in the case of `jsinspector`, as the library contains singletons which can be inadvertently duplicated due to static linking. As a result, different parts of the code can end up accessing different instances of a supposed singleton, leading to bugs. Here we revert the change to `jsinspector` (only) and add an explanatory comment to signpost this for future readers. ## More context & general principle While nothing is broken today, allowing static libraries to contain global state is brittle and breaks in surprising ways: * The upcoming diff D52231237 introduces a new dependency on `jsinspector` which builds cleanly, but causes debugging to stop working because of the duplicated singleton. * The only reason debugging currently works in the CMake build of Bridgeless is by a happy accident: the shared library `hermesinstancejni` depends on `reactnativejni` through a chain of three other libraries unrelated to debugging, and as a result, can access `reactnativejni`'s copy of `jsinspector` (see graph). {F1237835169} It seems that the safest rule of thumb, given the way React Native is currently structured, is that **singletons should live in their own shared libraries** so no call site can cause them to be duplicated through static linking. (It's reasonable to revisit this guidance if we manage to consolidate React Native into one monolithic shared library, eliminating the footgun at the source.) Changelog: [Internal] [Changed] - Change jsinspector back to a shared library in the CMake build. Reviewed By: cortinico, NickGerleman Differential Revision: D52541488 fbshipit-source-id: 502210add0b734a9bbc470bdf38fb70a41e149a9
React Native
Learn once, write anywhere:
Build mobile apps with React.
Getting Started · Learn the Basics · Showcase · Contribute · Community · Support
React Native brings React's declarative UI framework to iOS and Android. With React Native, you use native UI controls and have full access to the native platform.
- Declarative. React makes it painless to create interactive UIs. Declarative views make your code more predictable and easier to debug.
- Component-Based. Build encapsulated components that manage their state, then compose them to make complex UIs.
- Developer Velocity. See local changes in seconds. Changes to JavaScript code can be live reloaded without rebuilding the native app.
- Portability. Reuse code across iOS, Android, and other platforms.
React Native is developed and supported by many companies and individual core contributors. Find out more in our ecosystem overview.
Contents
- Requirements
- Building your first React Native app
- Documentation
- Upgrading
- How to Contribute
- Code of Conduct
- License
📋 Requirements
React Native apps may target iOS 13.4 and Android 6.0 (API 23) or newer. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS. Tools like Expo can be used to work 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:
📖 Documentation
The full documentation for React Native can be found on our website.
The React Native documentation discusses components, APIs, and topics that are specific to React Native. For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
The source for the React Native documentation and website is hosted on a separate repo, @facebook/react-native-website.
🚀 Upgrading
Upgrading to new versions of React Native may give you access to more APIs, views, developer tools, and other goodies. See the Upgrading Guide for instructions.
React Native releases are discussed in this discussion repo.
👏 How to Contribute
The main purpose of this repository is to continue evolving React Native core. We want to make contributing to this project as easy and transparent as possible, and we are grateful to the community for contributing bug fixes and improvements. Read below to learn how you can take part in improving React Native.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our Contributing Guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React Native.
Open Source Roadmap
You can learn more about our vision for React Native in the Roadmap.
Good First Issues
We have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started, gain experience, and get familiar with our contribution process.
Discussions
Larger discussions and proposals are discussed in @react-native-community/discussions-and-proposals.
📄 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.