@react-native/jest-preset
Jest preset for React Native apps
About
Jest preset for React Native apps
Live mirror of the GitHub README. Updated whenever the repo's default branch changes.
@react-native/jest-preset
Jest preset for React Native apps.
Usage
Installation
Install @react-native/jest-preset in your app:
with npm:
npm i @react-native/jest-preset --save-dev
or with yarn:
yarn add -D @react-native/jest-preset
Configuring Jest
Then, create a file called jest.config.js in your project's root directory. Then load this preset:
module.exports = {
preset: '@react-native/jest-preset',
};
You can further customize your Jest configuration by specifying other options. See Jest's jest.config.js documentation to learn more.
Migration Note
This Jest preset used to be part of the core react-native package and accessible at react-native/jest-preset.js. As long as @react-native/jest-preset is installed, react-native/jest-preset.js will be aliased to this package and continue to work but is deprecated.
Follow the installation instructions above to migrate to @react-native/jest-preset and change preset: 'react-native' to preset: '@react-native/jest-preset to migrate.
Quick facts
npm install @react-native/jest-presetCommon pairings
Packages this one expects to find in the same project. Each is also a Sourcemap Explorer detection target.
How Sourcemap Explorer detects @react-native/jest-preset
We catch @react-native/jest-preset from two complementary signals: bundled source paths and the embedded package.json. Modern bundlers (webpack, Vite, esbuild, Rollup, Turbopack) preserve the original node_modules/@react-native/jest-preset/ paths inside the JavaScript sourcemap's sources[] array — that's the canonical signal. When the matching package.json is also captured in sourcesContent[], we read the exact version field — patch number included. No regex guessing, no version inference.
- 1
Confirm the site exposes sourcemaps
In DevTools Network, check the response headers of any application script for `SourceMap` or `X-SourceMap`. Failing that, fetch the script's last 4 KB and look for a `//# sourceMappingURL=` comment.
- 2
Find the package in the bundle
Open DevTools → Network → reload. Click any application script and look at its sourcemap. Inside, search `sources[]` for entries matching `node_modules/@react-native/jest-preset/` — every match confirms the package is bundled. The matching `sourcesContent[i]` for `node_modules/@react-native/jest-preset/package.json` gives you the exact installed version.
- 3
Read the version directly from package.json
Run `jq -r '. as $m | $m.sources | to_entries[] | select(.value | endswith("node_modules/@react-native/jest-preset/package.json")) | $m.sourcesContent[.key] | fromjson | .version' bundle.js.map`. Sourcemap Explorer automates the same query in the popup.
Recent versions
FAQ
What is @react-native/jest-preset used for?
Jest preset for React Native apps
How can I tell if a website is using @react-native/jest-preset?
Open the page in Chrome with the Sourcemap Explorer extension installed and read the Stack tab. We catch `@react-native/jest-preset` from two complementary signals: `node_modules/@react-native/jest-preset/` paths inside the JavaScript sourcemap, and the embedded `package.json` we read for exact-version detection. Without the extension you can do the same lookup manually in DevTools — the steps are listed in the "How Sourcemap Explorer detects" section above.
What is the latest version of @react-native/jest-preset?
0.85.3, as published on the npm registry. The "Recent versions" table on this page lists the most recent 4 releases with their release dates. Sourcemap Explorer reports the version actually bundled into a site, which can lag the latest release by months on real-world deployments.
Where can I read more?
Project homepage: https://github.com/facebook/react-native#readme. Source code: https://github.com/facebook/react-native. Published on npm: https://www.npmjs.com/package/@react-native/jest-preset. Licensed as MIT.
Detected by Sourcemap Explorer
When a bundle ships sourcemaps, we read the embedded package.json for @react-native/jest-preset and report the precise version. Without sourcemaps, an import / require in the page's scripts is enough to flag it.