Migrating AsyncStorage after ejecting from Expo (SDK 34)

AsyncStorageMigration.java

package com.company.project;

import java.io.File;
import java.net.URLEncoder;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

import com.facebook.react.modules.storage.ReactDatabaseSupplier;

public class AsyncStorageMigration {
    static final String LOG_TAG = "expo_storage_migration";

    static final String PERSIST_KEY = "persist:root";
    static final String TABLE_CATALYST = "catalystLocalStorage";
    static final String KEY_COLUMN = "key";
    static final String VALUE_COLUMN = "value";

    private static Context mContext;
    private static String expoDatabaseName;

    public static void migrate(Context context) {
        mContext = context;

        expoDatabaseName = getExpoDatabaseName();
        if (expoDatabaseName.length() == 0)
            return;

        Boolean expoDatabaseExists = checkExpoDatabase();
        if (!expoDatabaseExists) {
            Log.v(LOG_TAG, "Expo AsyncStorage was previously migrated. Exiting migration...");
            return;
        }

        String data = getOldData();
        if (data.length() == 0) {
            Log.v(LOG_TAG, "Could not get old data. Exiting migration...");
            return;
        }

        if (!deleteOldDatabase()) {
            Log.v(LOG_TAG, "Could not delete old database. Exiting migration...");
            return;
        }

        populateNewStore(data);

        Log.v(LOG_TAG, "Migration done!");
    }

    private static String getExpoDatabaseName() {
        String databaseName = "";
        String experienceId = getExperienceId();

        if (experienceId == null || experienceId.length() == 0) {
            Log.v(LOG_TAG, "No Experience ID. Exiting migration...");
        } else {
            try {
                String experienceIdEncoded = URLEncoder.encode(experienceId, "UTF-8");
                databaseName = "RKStorage-scoped-experience-" + experienceIdEncoded;
            } catch (Exception e) {
                Log.e(LOG_TAG, "Could not get Expo database name");
            }
        }
        return databaseName;
    }

    private static String getExperienceId() {
        return BuildConfig.LEGACY_EXPO_EXPERIENCE_ID;
    }

    private static boolean checkExpoDatabase() {
        File dbFile = mContext.getDatabasePath(expoDatabaseName);
        return dbFile.exists();
    }

    private static String getOldData() {
        String data = "";
        SQLiteDatabase readableDatabase = null;
        Cursor cursor = null;

        try {
            String databasePath = mContext.getDatabasePath(expoDatabaseName).getPath();
            readableDatabase = SQLiteDatabase.openDatabase(databasePath, null, SQLiteDatabase.OPEN_READONLY);

            cursor = readableDatabase.query(TABLE_CATALYST, new String[]{VALUE_COLUMN}, KEY_COLUMN + " = ?", new String[]{PERSIST_KEY}, null, null, null);

            if (cursor != null && cursor.moveToFirst()) {
                data = cursor.getString(cursor.getColumnIndex(VALUE_COLUMN));
            }
        } catch (Exception e) {
            Log.e(LOG_TAG, "Get old data error: " + e.getMessage());
        } finally {
            if (readableDatabase != null) {
                readableDatabase.close();
            }
        }

        return data;
    }

    private static Boolean deleteOldDatabase() {
        return mContext.deleteDatabase(expoDatabaseName);
    }

    private static void populateNewStore(String value) {
        SQLiteDatabase readableDatabase = null;

        try {
            readableDatabase = ReactDatabaseSupplier.getInstance(mContext).getReadableDatabase();

            // Check if entry exists
            Cursor cursor = readableDatabase.query(TABLE_CATALYST, new String[]{VALUE_COLUMN}, KEY_COLUMN + " = ?", new String[]{PERSIST_KEY}, null, null, null);
            boolean entryExists = cursor.getCount() != 0;
            cursor.close();

            ContentValues args = new ContentValues();
            args.put(KEY_COLUMN, PERSIST_KEY);
            args.put(VALUE_COLUMN, value);

            // Update value
            if (entryExists) {
                Log.v(LOG_TAG, "Entry already exists, ready for update...");
                readableDatabase.update(TABLE_CATALYST, args, KEY_COLUMN + " = ?", new String[]{PERSIST_KEY});
            }
            // Insert value
            else {
                Log.v(LOG_TAG, "Entry does not exists, ready for insertion...");
                readableDatabase.insert(TABLE_CATALYST, null, args);
            }
        } catch (Exception e) {
            Log.e(LOG_TAG, "Populate error: " + e.getMessage());
        } finally {
            if (readableDatabase != null) {
                readableDatabase.close();
            }
        }
    }
}

This is how I migrated my AsyncStorage data on Android after ejecting from Expo 😁

If your Experience ID is @project-owner/project, Expo database name will be RKStorage-scoped-experience-%40project-owner%2Fproject.

Because I'm using Redux Persist on my project, I only need to copy the entry with the persist:root key from Expo database to the React Native one.

MainApplication.java

 @Override
 public void onCreate() {
        super.onCreate();
+       AsyncStorageMigration.migrate(getApplicationContext());
        SoLoader.init(this, /* native exopackage */ false);
 }

build.gradle

 buildTypes {
        debug {
             ...
+            buildConfigField "String", "LEGACY_EXPO_EXPERIENCE_ID", "\"@project-owner/project\""
        }
}

Hi @ericluong, thanks for providing this solution. Can you say where did you put AsyncStorageMigration.java file in android folder?

Hello @yaroslavnikiforov, this file is located next to the MainApplication.java and MainActivity.java files in android/app/src/main/java/project/path

Thanks, @ericluong, this solution works great

@yaroslavnikiforov You're welcome! Migrating out of Expo was painful (especially with an app in production) but it has been worth it

Thank you for the solution, if you are not using Redux this can be useful too: https://gist.github.com/luizjr92/db091719f09617abc5909ba64485e395

Guys, I just want to say thank you for this!