Export getReactNativePersistence function (#5711)

Author: sam-gc

packages/auth/index.rn.ts

@@ -59,6 +59,8 @@ export { PhoneMultiFactorGenerator } from './src/platform_browser/mfa/assertions
 export const reactNativeLocalPersistence: Persistence =
   getReactNativePersistence(AsyncStorage);
 
+export {getReactNativePersistence};
+
 export function getAuth(app: FirebaseApp = getApp()): Auth {
   const provider = _getProvider(app, 'auth');
 

packages/auth/src/platform_react_native/persistence/react_native.ts

@@ -26,22 +26,21 @@ import {
 } from '../../core/persistence';
 
 /**
- * Returns a persistence class that wraps AsyncStorage imported from
- * `react-native` or `@react-native-community/async-storage`.
- *
- * Creates a "new"-able subclass on the fly that has an empty constructor.
- *
- * In the _getInstance() implementation (see src/core/persistence/index.ts),
- * we expect each "externs.Persistence" object passed to us by the user to
- * be able to be instantiated (as a class) using "new". That function also
- * expects the constructor to be empty. Since ReactNativeStorage requires the
- * underlying storage layer, we need to be able to create subclasses
- * (closures, esentially) that have the storage layer but empty constructor.
+ * Returns a persistence object that wraps AsyncStorage imported from
+ * `react-native` or `@react-native-community/async-storage`, and can
+ * be used in the persistence dependency field in {@link initializeAuth}.
+ * 
+ * @public
  */
-
 export function getReactNativePersistence(
   storage: ReactNativeAsyncStorage
 ): Persistence {
+  // In the _getInstance() implementation (see src/core/persistence/index.ts),
+  // we expect each "externs.Persistence" object passed to us by the user to
+  // be able to be instantiated (as a class) using "new". That function also
+  // expects the constructor to be empty. Since ReactNativeStorage requires the
+  // underlying storage layer, we need to be able to create subclasses
+  // (closures, esentially) that have the storage layer but empty constructor.
   return class implements PersistenceInternal {
     static type: 'LOCAL' = 'LOCAL';
     readonly type: PersistenceType = PersistenceType.LOCAL;