1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85# 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-extractor](https://www.npmjs.com/package/flow-api-translator)
- TypeScript → (initial) API rollup: [@microsoft/api-extractor](https://api-extractor.com/)
## Usage
#### Build generated types + API snapshot
Maintainers should run this script whenever making intentional API changes.
```sh
# 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.
```sh
# Compare two versions of the API snapshot
yarn js-api-diff <before.d.ts> <after.d.ts>
```
```json
{
"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.ts` entry point via `package.json#exports`.
- Preserves `unstable_` and `experimental_` APIs.
- Preserves doc comments.
- Preserves source file names (for go to definition).
### Public API snapshot
`ReactNative.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_` and `experimental_` 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.