A declarative, efficient, and flexible JavaScript library for building user interfaces. reactjs.org
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Andrew Clark af219cc6e6
Lint rule to forbid access of cross-fork fields (#19679)
* Lint rule to forbid access of cross-fork fields

We use a shared Fiber type for both reconciler forks (old and new). It
is a superset of all the fields used by both forks. However, there are
some fields that should only be used in the new fork, and others that
should only be used in the old fork.

Ideally we would enforce this with separate Flow types for each fork.
The problem is that the Fiber type is accessed by some packages outside
the reconciler (like React DOM), and get passed into the reconciler as
arguments. So there's no way to fork the Fiber type without also forking
the packages where they are used. FiberRoot has the same issue.

Instead, I've added a lint rule that forbids cross-fork access of
fork-specific fields. Fields that end in `_old` or `_new` are forbidden
from being used inside the new or old fork respectively. Or you can
specific custom fields using the ESLint plugin options.

I used this plugin to find and remove references to the effect list
in d2e914a.

* Mark effect list fields as old

And `subtreeTag` as new.

I didn't mark `lastEffect` because that name is also used by the
Hook type. Not super important; could rename to `lastEffect_old` but
idk if it's worth the effort.
2020-08-24 10:07:11 -07:00
.circleci Speed up yarn cache in circle (#19566) 2020-08-11 14:05:15 -04:00
.codesandbox chore: Build react-dom/test-utils in codesandbox deploy (#19321) 2020-07-13 16:15:37 +01:00
.github Fix spelling errors and typos (#19138) 2020-06-15 19:59:44 -04:00
fixtures Nesting Fixture (#19531) 2020-08-07 02:08:41 +01:00
packages Attach Listeners Eagerly to Roots and Portal Containers (#19659) 2020-08-24 16:50:20 +01:00
scripts Lint rule to forbid access of cross-fork fields (#19679) 2020-08-24 10:07:11 -07:00
.editorconfig https link to editorconfig.org (#18421) 2020-03-29 15:18:52 +01:00
.eslintignore Import React Concurrent Mode Profiler (#19634) 2020-08-20 14:06:28 -04:00
.eslintrc.js Lint rule to forbid access of cross-fork fields (#19679) 2020-08-24 10:07:11 -07:00
.gitattributes .gitattributes to ensure LF line endings when we should 2014-01-17 16:25:53 -08:00
.gitignore Import React Concurrent Mode Profiler (#19634) 2020-08-20 14:06:28 -04:00
.mailmap Update my mailmap entries (#19455) 2020-07-26 22:47:32 -04:00
.nvmrc Update nvmrc to the same one used in CI (#18623) 2020-04-15 16:03:02 -07:00
.prettierignore Import React Concurrent Mode Profiler (#19634) 2020-08-20 14:06:28 -04:00
.prettierrc.js Bump Prettier (#17811) 2020-01-09 13:54:11 +00:00
.watchmanconfig .watchmanconfig must be valid json (#16118) 2019-07-11 19:01:02 -07:00
appveyor.yml Revert "Move MS Windows build to CircleCI (#17984)" (#18302) 2020-03-12 20:57:13 -07:00
AUTHORS Update authors for v16 (#10861) 2017-09-27 10:24:16 +01:00
babel.config.js Babel 7 (#16297) 2019-08-08 17:46:35 -07:00
CHANGELOG.md Clarifications 2020-06-12 21:09:29 -04:00
CODE_OF_CONDUCT.md Adopt Contributor Covenant (#16613) 2019-08-29 16:04:47 -07:00
CONTRIBUTING.md [Gatsby] "https://facebook.github.io/react/" -> "https://reactjs.org/" (#10970) 2017-09-29 18:43:22 -07:00
dangerfile.js fix sizebot - point correctly to circleci artifact (#17975) 2020-02-04 14:03:12 -08:00
LICENSE Drop the year from Facebook copyright headers and the LICENSE file. (#13593) 2018-09-07 15:11:23 -07:00
netlify.toml add netlify toml file (#12350) 2018-05-20 21:03:51 +01:00
package.json Upgrade all @babel/* packages to fix DevTools builds on newer Node versions (#19647) 2020-08-20 11:47:16 -04:00
README.md Update README.md 2020-07-08 18:30:18 +01:00
SECURITY.md Create SECURITY.md (#15784) 2020-01-09 14:07:41 -08:00
yarn.lock Import React Concurrent Mode Profiler (#19634) 2020-08-20 14:06:28 -04:00

React · GitHub license npm version CircleCI Status PRs Welcome

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 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 own 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:

You can use React as a <script> tag from a CDN, or as a react package on npm.

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:

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:

function HelloMessage({ name }) {
  return <div>Hello {name}</div>;
}

ReactDOM.render(
  <HelloMessage name="Taylor" />,
  document.getElementById('container')
);

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. If you're using React as a <script> tag, read this section on integrating JSX; otherwise, the recommended JavaScript toolchains handle it automatically.

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 which have a relatively limited scope. This is a great place to get started.

License

React is MIT licensed.