Alex Hunt
2991a97731
Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/56772 Upgrades to TypeScript 6.0.3 and updates `typescript-eslint/*` for TS 6.0 compatibility across `react-native` and `metro`. #### Motivation TypeScript 6.0 (Mar 2026) will resolve https://github.com/facebook/react-native/issues/53565. Before updating in the React Native CLI template, align in RN and Metro source for consistency. This is an internal change since: - This upgrade only applies to TS analysis of these repos' source code. - Edits to `react-native/typescript-config/tsconfig.json` (which *is* distributed) maintain backwards compatibility. #### Changes **react-native** - Bump `typescript` from `^5.8.3` to `^6.0.3` - Bump `typescript-eslint/*` from `^8.24.0` to `^8.59.2` - Replace deprecated `moduleResolution: "node"` with `"node16"` and `target: "es5"` with `"es2015"` in codegen-typescript-test - Add explicit `types: ["jest", "node"]` where needed (TS 6.0 defaults `types` to `[]`) - Set `strict: false` in configs that only enable specific strict flags (TS 6.0 defaults `strict` to `true`) - Update `ModuleResolutionKind.NodeJs` to `Node16` in build config **metro** - Bump `typescript` from `5.8.3` to `^6.0.3` - Bump `typescript-eslint/*` from `^8.36.0` to `^8.59.2` - No tsconfig changes needed (`tsconfig/node20` preset is already TS 6.0 compatible) Changelog: [Internal] Reviewed By: christophpurrer Differential Revision: D104658690 fbshipit-source-id: 9a2feeb257d5783431941a911b17065fcd0389a5
scripts/js-api
TypeScript build pipeline for React Native's JavaScript API.
Overview
yarn build-types is a custom build pipeline for translating React Native's Flow source code to TypeScript.
Specifically, it reduces the runtime JavaScript API of react-native into two outputs:
- Generated TypeScript types
Public user types for react-native, shipped to npm
packages/react-native/types_generated/ - Public API snapshot
Snapshot file of the public API shape, used by maintainers
packages/react-native/ReactNativeApi.d.ts
Dependencies
yarn build-types makes use of the following dependencies, composed with other pre/post transformation steps and dependency resolution.
- Flow → TypeScript conversion: flow-api-translator
- TypeScript → (initial) API rollup: @microsoft/api-extractor
Usage
Build generated types + API snapshot
Maintainers should run this script whenever making intentional API changes.
# Build types + API snapshot
yarn build-types [--validate]
# Build types without API snapshot
yarn build-types --skip-snapshot
Diff API snapshot compatibility
This script is run by CI to compare changes to ReactNativeApi.d.ts between commits.
# Compare two versions of the API snapshot
yarn js-api-diff <before.d.ts> <after.d.ts>
{
"result": "BREAKING",
"changedApis": [
"ViewStyle"
]
}
Configuration
Sparse configuration options are defined and documented in scripts/js-api/config.js.
About the two output formats
Generated TypeScript types
types_generated/
Directory providing TypeScript user types for the react-native package, distributed via npm.
- Gitignored.
- Scoped to the
index.d.tsentry point viapackage.json#exports. - Preserves
unstable_andexperimental_APIs. - Preserves doc comments.
- Preserves source file names (for go to definition).
Public API snapshot
ReactNativeApi.d.ts
Provides a human-readable, maintainable reference of the React Native's public JavaScript API, optimized for developers and diff tooling.
- Committed to the repo.
- Strips
unstable_andexperimental_APIs. - Strips doc comments.
- Strips source file names (types are merged into a single program).
- Versions exported APIs with an 8 char SHA hash, which will be updated when any input type dependencies change shape.