This is a simple ruby script to backup react-native AsyncStorage in iOS Simulator. So we can backup and restore the whole redux store in AsyncStorage for development.

backup_react_native_async_storage.rb

#!/usr/bin/env ruby

# backup workbench.app's AsyncStorage filesystem, so we can restore the whole redux store for development.

require "open3"

Open3.popen3("ps ax | grep workbench.app | awk '{print $5}' ") { |stdin, stdout, stderr| 
    process_name = stdout.readlines()[0]
    base_dir = process_name.split('/data/')[0]

    # Ref: node_modules/react-native/React/Modules/RCTAsyncLocalStorage.m
    async_storage_dir = `find #{base_dir} -name "RCTAsyncLocalStorage_V1"`

    timestamp = `date +"%Y%m%d_%H%M_%S"`
    backup_dir = "~/workbench_async_storage_backup/#{timestamp}"
    `mkdir -p #{backup_dir}`
    `cp -Rfp #{async_storage_dir.strip()} #{backup_dir}`

    puts "workbench.app's AsyncStorage have been backuped to #{backup_dir}"
    puts "You can restore it to #{async_storage_dir}"
}

This script only works for iOS.
Please replace workbench.app with your target react-native app in iOS Simulator.

On iOS, AsyncStorage is backed by native code that stores small values in a serialized dictionary and larger values in separate files.
On Android, AsyncStorage will use either RocksDB or SQLite based on what is available.

Ref: https://facebook.github.io/react-native/docs/asyncstorage.html