android-persistence

name	android-persistence
description	Standards for Room Database and DataStore. Use when implementing Room database schemas or DataStore preferences in Android. (triggers: **/*Dao.kt, **/*Database.kt, **/*Entity.kt, @Dao, @Entity, RoomDatabase)

Android Persistence Standards

Priority: P0

Implementation Guidelines

Room

• Async: Return Flow<List<T>> for queries, use suspend for Write/Insert.
• Entities: Keep simple @Entity data classes. Map to Domain models in Repository.
• Transactions: Use @Transaction for multi-table queries (Relations).

DataStore

• Usage: Replace SharedPreferences with ProtoDataStore (Type-safe) or PreferencesDataStore.
• Scope: Inject singleton instance via Hilt.

Anti-Patterns

• No IO on Main Thread: Room handles dispatchers, but verify Flow is collected off-main.
• No @Entity in UI Layer: Map to Domain or UI models in Repository.

References

• DAO Templates