KeyValueStorage - How to decouple SharedPreferences on Android

KeyValueStorage.kt

interface KeyValueStorage {

  fun getAll(): Map<String, *>

  fun contains(key: String): Boolean

  fun remove(key: String): Boolean

  fun getBoolean(key: String, defaultValue: Boolean): Boolean
  fun putBoolean(key: String, value: Boolean): Boolean

  fun getFloat(key: String, defaultValue: Float): Float
  fun putFloat(key: String, value: Float): Boolean

  fun getLong(key: String, defaultValue: Long): Long
  fun putLong(key: String, value: Long): Boolean

  fun getInt(key: String, defaultValue: Int): Int
  fun putInt(key: String, value: Int): Boolean

  fun getStringSet(key: String, defaultValue: Set<String>): Set<String>
  fun putStringSet(key: String, value: Set<String>): Boolean

  fun getString(key: String, defaultValue: String): String
  fun putString(key: String, value: String): Boolean
}

KeyValueStorageFactory.kt

class KeyValueStorageFactory {

    companion object {

        fun build(
            context: Context,
            storeName: String
        ): KeyValueStorage {
            val sp = context.getSharedPreferences(storeName, Context.MODE_PRIVATE)
            return KeyValueStorageSpImpl(sp)
        }

        fun build(sharedPreferences: SharedPreferences): KeyValueStorage = KeyValueStorageSpImpl(sharedPreferences)
    }

    class KeyValueStorageSpImpl(private val sp: SharedPreferences) : KeyValueStorage {

        override fun getAll(): Map<String, *> = sp.all

        override fun contains(key: String) = sp.contains(key)

        override fun remove(key: String) = sp.edit().remove(key).commit()

        override fun getBoolean(key: String, defaultValue: Boolean) = sp.getBoolean(key, defaultValue)

        override fun putBoolean(key: String, value: Boolean) = sp.edit().putBoolean(key, value).commit()

        override fun getFloat(key: String, defaultValue: Float) = sp.getFloat(key, defaultValue)

        override fun putFloat(key: String, value: Float) = sp.edit().putFloat(key, value).commit()

        override fun getLong(key: String, defaultValue: Long) = sp.getLong(key, defaultValue)

        override fun putLong(key: String, value: Long) = sp.edit().putLong(key, value).commit()

        override fun getInt(key: String, defaultValue: Int) = sp.getInt(key, defaultValue)

        override fun putInt(key: String, value: Int) = sp.edit().putInt(key, value).commit()

        override fun getStringSet(key: String, defaultValue: Set<String>): Set<String> = sp.getStringSet(key, defaultValue)

        override fun putStringSet(key: String, value: Set<String>) = sp.edit().putStringSet(key, value).commit()

        override fun getString(key: String, defaultValue: String): String = sp.getString(key, defaultValue)

        override fun putString(key: String, value: String) = sp.edit().putString(key, value).commit()
    }
}