chore: Add FDv2 example project for react-native.

package.json

@@ -25,6 +25,7 @@
     "packages/sdk/react/examples/vercel-edge",
     "packages/sdk/react-native",
     "packages/sdk/react-native/example",
+    "packages/sdk/react-native/example-fdv2",
     "packages/sdk/react-native/contract-tests/entity",
     "packages/sdk/vercel",
     "packages/sdk/svelte",

packages/sdk/react-native/example-fdv2/.env.example

@@ -0,0 +1 @@
+MOBILE_KEY=

packages/sdk/react-native/example-fdv2/.gitignore

@@ -0,0 +1,44 @@
+# Learn more https://docs.github.com/en/get-started/getting-started-with-git/ignoring-files
+.env
+
+# dependencies
+node_modules/
+
+# Expo
+.expo/
+dist/
+web-build/
+
+# Native
+*.orig.*
+*.jks
+*.p8
+*.p12
+*.key
+*.mobileprovision
+
+# Metro
+.metro-health-check*
+
+# debug
+npm-debug.*
+yarn-debug.*
+yarn-error.*
+
+# macOS
+.DS_Store
+*.pem
+
+# local env files
+.env*.local
+
+# typescript
+*.tsbuildinfo
+
+ios
+android
+
+!yarn.lock
+
+# detox
+artifacts

packages/sdk/react-native/example-fdv2/App.tsx

@@ -0,0 +1,27 @@
+import { MOBILE_KEY } from '@env';
+
+import {
+  AutoEnvAttributes,
+  LDProvider,
+  ReactNativeLDClient,
+} from '@launchdarkly/react-native-client-sdk';
+
+import Welcome from './src/welcome';
+
+const featureClient = new ReactNativeLDClient(MOBILE_KEY, AutoEnvAttributes.Enabled, {
+  debug: true,
+  applicationInfo: {
+    id: 'ld-rn-fdv2-test-app',
+    version: '0.0.1',
+  },
+  // @ts-ignore dataSystem is @internal
+  dataSystem: {},
+});
+
+const App = () => (
+  <LDProvider client={featureClient}>
+    <Welcome />
+  </LDProvider>
+);
+
+export default App;

packages/sdk/react-native/example-fdv2/README.md

@@ -0,0 +1,57 @@
+# LaunchDarkly React Native SDK - FDv2 Example App
+
+This is a minimal example app that demonstrates the experimental FDv2 data system
+for the React Native SDK.
+
+> **Note:** FDv2 support is `@internal` and experimental. It is not ready for
+> production use and may change or be removed without notice.
+
+## Features Demonstrated
+
+- SDK initialization with the `dataSystem` option (FDv2 protocol)
+- Connection mode switching for all FDv2 modes:
+  - **Streaming** - real-time flag updates with polling fallback
+  - **Polling** - periodic polling only
+  - **Offline** - cached flags only, no network
+  - **One-Shot** - initialize then stop (no persistent synchronizer)
+  - **Background** - low-frequency polling for background state
+  - **Automatic** - clear the override and use automatic mode selection
+- Context identification
+- Boolean flag evaluation
+
+## Quickstart
+
+1. At the js-core repo root, install dependencies and build:
+
+```shell
+yarn && yarn build
+```
+
+2. Create an `.env` file in this directory (`example-fdv2/`) with your mobile key:
+
+```shell
+MOBILE_KEY=mob-your-mobile-key-here
+```
+
+3. Update the flag key in `src/welcome.tsx` if needed (defaults to `sample-feature`).
+
+4. Run the app:
+
+```shell
+# iOS
+yarn ios
+
+# Android
+yarn android
+```
+
+> **Note:** You may need to run `npx expo prebuild` before the first iOS or
+> Android build.
+
+## Caveats
+
+- **Network-based automatic mode switching** is not yet implemented. The wiring
+  is in place, but `RNStateDetector` does not yet emit network state changes.
+  Lifecycle-based switching (foreground/background) works.
+- The `dataSystem` option and `setConnectionMode()` are marked `@internal` and
+  require `@ts-ignore` to use from TypeScript.

packages/sdk/react-native/example-fdv2/app.json

@@ -0,0 +1,20 @@
+{
+  "expo": {
+    "name": "react-native-example-fdv2",
+    "slug": "react-native-example-fdv2",
+    "version": "1.0.0",
+    "orientation": "portrait",
+    "userInterfaceStyle": "light",
+    "assetBundlePatterns": ["**/*"],
+    "ios": {
+      "supportsTablet": true,
+      "bundleIdentifier": "com.anonymous.reactnativeexamplefdv2"
+    },
+    "android": {
+      "adaptiveIcon": {
+        "backgroundColor": "#ffffff"
+      },
+      "package": "com.anonymous.reactnativeexamplefdv2"
+    }
+  }
+}

packages/sdk/react-native/example-fdv2/babel.config.js

@@ -0,0 +1,15 @@
+module.exports = function (api) {
+  api.cache(true);
+  return {
+    presets: ['babel-preset-expo'],
+    plugins: [
+      [
+        'module:react-native-dotenv',
+        {
+          safe: true,
+          allowUndefined: false,
+        },
+      ],
+    ],
+  };
+};

packages/sdk/react-native/example-fdv2/index.js

@@ -0,0 +1,10 @@
+// We have to use a custom entrypoint for monorepo workspaces to work.
+// https://docs.expo.dev/guides/monorepos/#change-default-entrypoint
+import { registerRootComponent } from 'expo';
+
+import App from './App';
+
+// registerRootComponent calls AppRegistry.registerComponent('main', () => App);
+// It also ensures that whether you load the app in Expo Go or in a native build,
+// the environment is set up appropriately
+registerRootComponent(App);

packages/sdk/react-native/example-fdv2/metro.config.js

@@ -0,0 +1,26 @@
+// We need to use a custom metro config for monorepo workspaces to work.
+// https://docs.expo.dev/guides/monorepos/#modify-the-metro-config
+/**
+ * @type {import('expo/metro-config')}
+ */
+const { getDefaultConfig } = require('expo/metro-config');
+const path = require('path');
+
+// Find the project and workspace directories
+const projectRoot = __dirname;
+// This can be replaced with `find-yarn-workspace-root`
+const workspaceRoot = path.resolve(projectRoot, '../../../..');
+
+const config = getDefaultConfig(projectRoot);
+
+// 1. Watch all files within the monorepo
+config.watchFolders = [workspaceRoot];
+// 2. Let Metro know where to resolve packages and in what order
+config.resolver.nodeModulesPaths = [
+  path.resolve(projectRoot, 'node_modules'),
+  path.resolve(workspaceRoot, 'node_modules'),
+];
+// 3. Force Metro to resolve (sub)dependencies only from the `nodeModulesPaths`
+config.resolver.disableHierarchicalLookup = true;
+
+module.exports = config;

packages/sdk/react-native/example-fdv2/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "@launchdarkly/react-native-example-fdv2",
+  "private": true,
+  "version": "0.0.1",
+  "main": "index.js",
+  "scripts": {
+    "start": "expo start --reset-cache",
+    "android": "expo run:android",
+    "ios": "expo run:ios",
+    "web": "expo start --web --clear"
+  },
+  "dependencies": {
+    "@launchdarkly/react-native-client-sdk": "10.15.2",
+    "@react-native-async-storage/async-storage": "^2.0.0",
+    "expo": "52.0.14",
+    "expo-status-bar": "~1.11.1",
+    "react": "18.3.1",
+    "react-native": "0.76.3",
+    "react-native-dotenv": "^3.4.9"
+  },
+  "devDependencies": {
+    "@babel/core": "^7.20.0",
+    "@types/react": "~18.2.55",
+    "@types/react-native-dotenv": "^0.2.1",
+    "typescript": "^5.2.2"
+  },
+  "packageManager": "yarn@3.4.1",
+  "installConfig": {
+    "hoistingLimits": "workspaces"
+  }
+}