react-native-swivel

react-native-swivel contains the development-time Fast Refresh infrastructure for Swivel-generated React Native bindings. Public dev APIs and library internals use refresh naming. Per-generation dynamic libraries use loadable naming.

Metro

Wrap the normal Metro configuration:

const {getDefaultConfig} = require('@react-native/metro-config');
const {withSwivel} = require('react-native-swivel/metro');

module.exports = withSwivel(getDefaultConfig(__dirname), {
  projectRoot: __dirname,
  outputDir: '.swivel/build',
  buildCommand: ['swift', 'swivel', 'build-loadable'],
});

The command receives --generation, --changed-file, and --output-dir. It must print one JSON object:

{
  "platform": "ios",
  "fileName": "libSwiveled_gen000042.dylib",
  "absolutePath": "/project/.swivel/build/libSwiveled_gen000042.dylib",
  "schemaHash": "8e21c9fa7b45a1d0",
  "abiHash": "1111222233334444"
}

For custom build orchestration, pass an async buildLoadable(context) callback instead. The callback receives an AbortSignal so a stale build can stop work when a newer Swift edit arrives.

App Client

Install the debug client once during app startup:

import {installSwivelFastRefresh} from 'react-native-swivel';

installSwivelFastRefresh();

Register app-owned handle reacquisition callbacks with NativeHandleRegistry.register(...).

Native

The package includes debug native modules for iOS and Android. They resolve the Metro host, download a loadable generation artifact into app-private storage, and pass its unique path to SwivelRefresher, which registers it as the new hot generation. Prior generations become warm: they stay dlopen'd for the app session so old HostObjects and Swift metadata stay valid.

The platform-specific loadable-library builder remains app-owned because it needs the app scheme, simulator architecture, Android ABI, Swift package path, and signing setup. Every loadable library must export the loadable registration ABI in native/cpp/SwivelLoadableABI.h.