@react-native-async-storage/async-storage/src/shouldFallbackToLegacyNativeModule.ts

Asynchronous, persistent, key-value storage system for React Native.

import { NativeModules } from 'react-native';

export function shouldFallbackToLegacyNativeModule(): boolean {
  const expoConstants =
    NativeModules['NativeUnimoduleProxy']?.modulesConstants?.ExponentConstants;

  if (expoConstants) {
    /**
     * In SDK <= 39, appOwnership is defined in managed apps but executionEnvironment is not.
     * In bare React Native apps using expo-constants, appOwnership is never defined, so
     * isLegacySdkVersion will be false in that context.
     */
    const isLegacySdkVersion =
      expoConstants.appOwnership && !expoConstants.executionEnvironment;

    /**
     * Expo managed apps don't include the @react-native-async-storage/async-storage
     * native modules yet, but the API interface is the same, so we can use the version
     * exported from React Native still.
     *
     * If in future releases (eg: @react-native-async-storage/async-storage >= 2.0.0) this
     * will likely not be valid anymore, and the package will need to be included in the Expo SDK
     * to continue to work.
     */
    if (
      isLegacySdkVersion ||
      ['storeClient', 'standalone'].includes(expoConstants.executionEnvironment)
    ) {
      return true;
    }
  }

  return false;
}