Backend Development Skill

Rules for the Rust "Engine" of EMMM2.

1. Core Architecture (The 3-Layer Standard)

Follow Clean Architecture to keep logic testable and decoupled.

1. Presentation (Commands): src-tauri/src/commands/. Thin wrapper. Deserializes input -> Calls Service -> Serializes Output. NO LOGIC HERE.
2. Domain (Services): src-tauri/src/services/. Pure Business Logic. Agnostic of Tauri or UI.
3. Infrastructure (Repositories): src-tauri/src/database/. SQLx queries and OS File I/O.

2. API Design (Tauri Commands)

Treat Commands like REST Endpoints.

• Input: Use DTO structs (Data Transfer Objects), not long argument lists.
• Output: Always return Result<T, AppError>.
• Async: All Commands must be async.

3. Database Patterns (SQLite + SQLx)

• Schema: managed via migrations/*.sql.
• ID: Use UUID v4 (Text) for universal uniqueness.
• Optimization: Use WAL mode and PRAGMA synchronous = NORMAL.

References

• Service Pattern
• Database & Schema
• API Style Guide