fix: support CSS asset resolution on React Native 0.87

[giaBaoJS]

Summary

Fixes #3015.

React Native 0.87 no longer installs @react-native/assets-registry transitively, so importing react-native-svg/css failed while Metro resolved LocalSvg and resolveAssetUri.

This change resolves native numeric assets through the public Image.resolveAssetSource API instead. That API is available across react-native-svg's supported React Native range and delegates to the registry owned by the installed React Native version.

The existing registry-based implementation is retained in resolveAssetUri.web.ts. React Native Web does not expose Image.resolveAssetSource, so using a platform file avoids changing its asset behavior.

I did not use either suggested React Native 0.87-only entry point:

• react-native/asset-registry is first exported in React Native 0.87;
• the root AssetRegistry named export is also absent in React Native 0.78–0.86.

Adding a standalone registry dependency would also risk resolving a different registry version/instance from the one used by React Native. The public Image resolver keeps the library compatible with React Native 0.78 through 0.87 without adding a dependency.

Test Plan

React Native 0.87 package-consumption reproduction

I packed the actual package, installed it into the repository's React Native 0.87 test app, removed access to parent node_modules, and bundled an entry importing react-native-svg/css.

Before the change:

error Unable to resolve module @react-native/assets-registry/registry from
node_modules/react-native-svg/src/lib/resolveAssetUri.ts:
@react-native/assets-registry/registry could not be found within the project
or in these directories:
  node_modules

The app had no direct node_modules/@react-native/assets-registry installation. With a tarball built from this branch, the same command succeeds:

Welcome to Metro v0.87.0
Writing bundle output to: /private/tmp/rnsvg3015-fixed.bundle
Done writing bundle output
Done in 1.89s.

Oldest supported representative

The same fixed tarball bundles successfully in an isolated React Native 0.78.3 consumer:

0.78.3 / react-native-svg 15.15.5 / assets-registry 0.78.3
Welcome to Metro v0.81.5
Writing bundle output to: /private/tmp/rnsvg3015-rn078.bundle
Done writing bundle output

Regression tests

Keeping the final tests while reverting only the native source change produces:

FAIL __tests__/resolveAssetUri.test.ts
  ✕ uses the public Image resolver for numeric native assets
  ✕ throws when the public Image resolver cannot find a native asset
  ✓ keeps using the web asset registry for numeric web assets
  ✓ throws when the web asset registry cannot find an asset
  ✓ keeps string, object and inline SVG URI behavior unchanged
  ✓ keeps string, object and inline SVG URI behavior unchanged

Tests: 2 failed, 4 passed, 6 total

Restoring the change gives 6/6 passing. I also inserted a deliberate failing sentinel into the new suite and confirmed Jest reported that exact assertion, proving the harness collects the file.

Final checks:

yarn test
# lint + tsc: pass

yarn bob
# commonjs + module + typescript: pass

yarn jest __tests__/resolveAssetUri.test.ts --runInBand \
  --config '{"rootDir":".","preset":"react-native","testEnvironment":"node"}'
# 1 suite, 6 tests: pass

npm pack --dry-run --ignore-scripts --json
# includes source, CommonJS, module, and type outputs for both platform files

yarn prettier --check src/lib/resolveAssetUri.ts \
  src/lib/resolveAssetUri.web.ts __tests__/resolveAssetUri.test.ts
# pass

Compatibility

OS	Implemented
iOS	✅
MacOS	✅
Android	✅
Web	✅

Checklist

• I have tested this on a device and a simulator (module-resolution change; verified through Metro bundles)
• I added documentation in README.md (not applicable)
• I updated the typed files (typescript)
• I added a test for the API in the __tests__ folder