react.dev/docs/addons.md

id	title	permalink
addons	Add-Ons	docs/addons.html

The React add-ons are a collection of useful utility modules for building React apps. These should be considered experimental and tend to change more often than the core.

• TransitionGroup and CSSTransitionGroup, for dealing with animations and transitions that are usually not simple to implement, such as before a component's removal.
• createFragment, to create a set of externally-keyed children.

The add-ons below are in the development (unminified) version of React only:

• Perf, a performance profiling tool for finding optimization opportunities.
• ReactTestUtils, simple helpers for writing test cases.

Legacy Add-ons

The add-ons below are considered legacy and their use is discouraged.

• PureRenderMixin. Use React.PureComponent instead.
• shallowCompare, a helper function that performs a shallow comparison for props and state in a component to decide if a component should update.
• update. Use kolodny/immutability-helper instead.

Deprecated Add-ons

LinkedStateMixin has been deprecated.

Using React with Add-ons

If using npm, you can install the add-ons individually from npm (e.g. npm install react-addons-test-utils) and import them:

import Perf from 'react-addons-perf'; // ES6
var Perf = require('react-addons-perf'); // ES5 with npm

When using a CDN, you can use react-with-addons.js instead of react.js:

<script src="https://unpkg.com/react@15/dist/react-with-addons.js"></script>

The add-ons will be available via the React.addons global (e.g. React.addons.TestUtils).