seanum Macro Documentation

Overview

The seanum procedural macro transforms a simple Rust enum into a fully-featured SeaORM active enum with database mapping capabilities. It automatically adds the necessary attributes, derives, and implementations to make the enum compatible with SeaORM's entity system.

Usage

Apply the #[seanum] attribute to an enum definition with the required parameters:

use rsmack_seanum::seanum;

#[seanum(rs_type = String, db_type = "Enum")]
pub enum SwitchAction {
    SendEmail,
    SendSms,
}

Parameters

The seanum macro accepts the following parameters:

• rs_type (Ident): The Rust type that represents the enum in the database (e.g., String, i32).
• db_type (LitStr): The database type for the enum (e.g., "Enum", "Text").

Transformation

When applied, the macro transforms the input enum by:

1. Adding necessary imports for SeaORM, serde, and fake
2. Adding a derive macro with various traits:
   • Clone - Enables cloning of the enum
   • Dummy - Enables generation of fake data for testing
   • Debug - Enables debug formatting
   • PartialEq - Enables partial equality comparison
   • EnumIter - Enables iteration over enum variants
   • DeriveActiveEnum - SeaORM's derive for active enums
   • Eq - Enables full equality comparison
   • Serialize - Enables serialization
   • Deserialize - Enables deserialization
3. Adding a #[sea_orm(...)] attribute to the enum with:
   • rs_type - The Rust type for the enum in the database
   • db_type - The database type for the enum
   • enum_name - The snake_case version of the enum name for database use
4. Adding #[sea_orm(string_value = "...")] attributes to each variant with the string representation of the variant name

Example

Input:

use rsmack_seanum::seanum;

#[seanum(rs_type = String, db_type = "Enum")]
pub enum SwitchAction {
    SendEmail,
    SendSms,
}

Output:

use fake::Dummy;
use sea_orm::entity::prelude::*;
use sea_orm_migration::prelude::*;
use serde::{Deserialize, Serialize};

#[derive(
    Clone, Dummy, Debug, PartialEq, EnumIter, DeriveActiveEnum, Eq, Serialize, Deserialize,
)]
#[sea_orm(rs_type = "String", db_type = "Enum", enum_name = "switch_action")]
pub enum SwitchAction {
    #[sea_orm(string_value = "SendEmail")]
    SendEmail,
    #[sea_orm(string_value = "SendSms")]
    SendSms,
}

Notes

• The macro automatically converts the enum name to snake_case for the database name (e.g., SwitchAction becomes switch_action)
• Each variant is mapped to its string representation in the database
• The generated enum is fully compatible with SeaORM's entity system and can be used in database operations
• The macro requires the megamac framework for proper execution

Dependencies

This macro requires the following dependencies:

• sea-orm - For the DeriveActiveEnum trait and related attributes
• sea-orm-migration - For database migration support
• serde - For serialization and deserialization
• fake - For generating fake data in tests