react-native/packages/react-native-babel-preset/README.md
Dmitry Rykun d380bb8473 Move react-native-babel-transformer and react-native-babel-preset from Metro to React Native repo (#38228)
Summary:
X-link: https://github.com/facebook/metro/pull/1024

Pull Request resolved: https://github.com/facebook/react-native/pull/38228

Changelog: [General][Changed] - Move react-native-babel-transformer and react-native-babel-preset from Metro to React Native repo.

Metro Changelog:  **[Breaking]** - Remove `metro-react-native-babel-transformer` and `metro-react-native-babel-preset`, to be published as `react-native/metro-babel-transformer` and `react-native/babel-preset` instead.

This diff does the following:
- Move `metro/packages/metro-react-native-babel-preset` to `react-native/packages/react-native-babel-preset`.
- Rename `metro-react-native-babel-preset` package to `react-native/babel-preset`.
- Move `metro/packages/metro-react-native-babel-transformer` to `react-native/packages/react-native-babel-transformer`.
- Rename `metro-react-native-babel-transformer` package to `react-native/metro-babel-transformer`.
- Upadate dependencies.

Reviewed By: robhogan

Differential Revision: D46977466

fbshipit-source-id: 32478f63a0442b61a1804f12ef814c8b29d7f8bb
2023-07-27 11:48:16 -07:00

1.6 KiB

@react-native/babel-preset

Babel presets for React Native applications. React Native itself uses this Babel preset by default when transforming your app's source code.

If you wish to use a custom Babel configuration by writing a babel.config.js file in your project's root directory, you must specify all the plugins necessary to transform your code. React Native does not apply its default Babel configuration in this case. So, to make your life easier, you can use this preset to get the default configuration and then specify more plugins that run before it.

Usage

As mentioned above, you only need to use this preset if you are writing a custom babel.config.js file.

Installation

Install @react-native/babel-preset in your app:

with npm:

npm i @react-native/babel-preset --save-dev

or with yarn:

yarn add -D @react-native/babel-preset

Configuring Babel

Then, create a file called babel.config.js in your project's root directory. The existence of this babel.config.js file will tell React Native to use your custom Babel configuration instead of its own. Then load this preset:

{
  "presets": ["module:@react-native/babel-preset"]
}

You can further customize your Babel configuration by specifying plugins and other options. See Babel's babel.config.js documentation to learn more.

Help and Support

If you get stuck configuring Babel, please ask a question on Stack Overflow or find a consultant for help. If you discover a bug, please open up an issue.