laurenandRaashish Aggarwal
d083ec1da1
`react-hooks/set-state-in-effect` flagged setState calls that happen after an `await` inside an async function invoked from an effect. Post-await code resumes in a microtask after the effect body has returned, so the "synchronous setState cascades a render" rationale does not apply; the lint was a false positive on a common data-loading shape (15 reactions on the issue). The fix exempts a setState only when it is *provably* post-await: a forward must-dataflow over the HIR CFG computes the blocks that begin after an await has executed on every path from the function entry (optimistic initialization so loop back-edges do not pessimize the meet, fixpoint to the greatest solution), plus an intra-block flag for instructions after an Await in the same block. A setState reachable on any await-free path still flags, so the conditional-await case remains an error by design, with a fixture documenting that choice. Suppression is sound under try/catch because HIRBuilder terminates blocks after each instruction in a try region, and an awaited rejection also resumes in a microtask. Fixtures: post-await setState (event gone), setState before the first await (still flags), setState after a conditional await (still flags). First commit documents the false positive via the lint-mode logger output, second removes it. Builds on the approach in #36417 by @raashish1601, hardened from a seen-await flag to the path-sensitive analysis above. Implemented identically in the TypeScript compiler and the Rust port. Verification: TS snap 1807/1807, Rust snap 1807/1807, cargo workspace green, scoped TS-vs-Rust HIR parity harness green. Closes #34905 --------- Co-authored-by: Raashish Aggarwal <94279692+raashish1601@users.noreply.github.com>
React · 
React is a JavaScript library for building user interfaces.
- Declarative: React makes it painless to create interactive UIs. Design simple views for each state in your application, and React will efficiently update and render just the right components when your data changes. Declarative views make your code more predictable, simpler to understand, and easier to debug.
- Component-Based: Build encapsulated components that manage their own state, then compose them to make complex UIs. Since component logic is written in JavaScript instead of templates, you can easily pass rich data through your app and keep the state out of the DOM.
- Learn Once, Write Anywhere: We don't make assumptions about the rest of your technology stack, so you can develop new features in React without rewriting existing code. React can also render on the server using Node and power mobile apps using React Native.
Learn how to use React in your project.
Installation
React has been designed for gradual adoption from the start, and you can use as little or as much React as you need:
- Use Quick Start to get a taste of React.
- Add React to an Existing Project to use as little or as much React as you need.
- Create a New React App if you're looking for a powerful JavaScript toolchain.
Documentation
You can find the React documentation on the website.
Check out the Getting Started page for a quick overview.
The documentation is divided into several sections:
- Quick Start
- Tutorial
- Thinking in React
- Installation
- Describing the UI
- Adding Interactivity
- Managing State
- Advanced Guides
- API Reference
- Where to Get Support
- Contributing Guide
You can improve it by sending pull requests to this repository.
Examples
We have several examples on the website. Here is the first one to get you started:
import { createRoot } from 'react-dom/client';
function HelloMessage({ name }) {
return <div>Hello {name}</div>;
}
const root = createRoot(document.getElementById('container'));
root.render(<HelloMessage name="Taylor" />);
This example will render "Hello Taylor" into a container on the page.
You'll notice that we used an HTML-like syntax; we call it JSX. JSX is not required to use React, but it makes code more readable, and writing it feels like writing HTML.
Contributing
The main purpose of this repository is to continue evolving React core, making it faster and easier to use. Development of React happens in the open on GitHub, and we are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving React.
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.
Good First Issues
To help you get your feet wet and get you familiar with our contribution process, we have a list of good first issues that contain bugs that have a relatively limited scope. This is a great place to get started.
License
React is MIT licensed.