[chrfalch]

Summary:

A library that supports React Native 0.87 must keep its SwiftPM settings in the deprecated spm block of react-native.config.js, because 0.87 reads only that block. To support 0.88 too, the library also declares the same settings in swiftpmConfig in its package.json. One example is @sentry/react-native, which sets name: "RNSentry" in both places.

React Native 0.88 warned about every field in the spm block, even when swiftpmConfig had the same value. Users of these libraries saw the warning on each spm add, spm update and Xcode sync. The library author could not fix it without dropping 0.87 support.

What changes:

1. A field in the spm block with the same value in swiftpmConfig is no longer warned about.
2. A field that is only in the spm block, or that has a different value in swiftpmConfig, is still warned about, with the same message as before.
3. The settings that React Native uses do not change. swiftpmConfig still wins over the spm block, field by field.

Changelog:

[IOS] [FIXED] - SwiftPM autolinking no longer warns about a deprecated spm field that swiftpmConfig in package.json sets to the same value

Test Plan:

Three new tests in packages/react-native/scripts/spm/__tests__/swiftpm-config-test.js: identical copies give no warning, a different value still warns, and the warning names only the fields that are not identical copies.

yarn jest --no-cache -i packages/react-native/scripts/spm/__tests__/swiftpm-config-test.js

• Without the source change: 3 failed, 37 passed (the 3 new tests fail).
• With the source change: 40 passed, 40 total.

yarn flow-check: 0 errors. ESLint (--max-warnings 0) and Prettier pass on both changed files.