Alex Hunt
cec189bd34
Summary: **Motivation** Minimum infra fix to enable subsequently landing https://github.com/react/react-native/pull/57940. Referencing `ReactNativeFeatureFlags` on the existing `react-native/react-private-interface` boundary is blocked by a gap in the `build-types` pipeline and a type translation error, addressed here. **Changes** - `simpleResolve.js`: Explicitly support `react-native/react-private-interface` as a special case, fixing resolution. - `ReactNativeFeatureFlagsBase.js`: Tweak the `OverridesFor` type here to fix TypeScript translation compatibility, where the unconstrained `T` type param is now narrowed. **Impact** No change to the API snapshot (the `ReactNativeFeatureFlags` import is ultimately tree-shaken!), and no effect on generated types until https://github.com/react/react-native/issues/57940 lands. Changelog: [Internal] Pull Request resolved: https://github.com/react/react-native/pull/58075 Test Plan: - `yarn build-types` - Applied https://github.com/react/react-native/issues/57940 patch on top; both stayed green, no `types_generated/**/featureflags/**` Reviewed By: GijsWeterings Differential Revision: D117513265 Pulled By: cortinico fbshipit-source-id: 348e8de3d622081fe0062ef939ce14c21af587a8
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.