Rob Hogan
2d2011c7ae
Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/53867 `react-native/metro-babel-transformer` implements `getCacheKey` for Metro, but does not vary the cache key on changes to `react-native/babel-preset`, one of its dependencies, leading to false positive cache hits (changes not being reflected). This is particularly a problem in development, although it potentially also leads to issues in the unusual case that `react-native/babel-preset` is updated via npm, but no other package is. This adds a `getCacheKey` to `react-native/babel-preset` and incorporates it into `react-native/metro-babel-transformer`'s `getCacheKey`. It's based on `package.json#version` in production and a hash of package contents in development (`version.endsWith('-main')`). Changelog: [General][Fixed] Invalidate transform cache when `react-native/babel-preset` is updated Reviewed By: huntie Differential Revision: D82893894 fbshipit-source-id: 9bbc034eaf68ee0e5b3078fb2fe8f30caa7f11c9
@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.