RabbitMesh Macros - The Magic Behind Zero-Port Microservices ✨

Procedural macros that transform simple Rust structs into complete microservices with automatic route generation and RabbitMQ RPC integration.

This crate provides the three core macros that make RabbitMesh's zero-configuration philosophy possible:

• #[service_definition] - Marks a struct as a RabbitMesh service
• #[service_impl] - Processes impl blocks to auto-register methods
• #[service_method] - Defines HTTP routes and RPC handlers

🪄 The Magic

Write this simple code:

use rabbitmesh_macros::{service_definition, service_impl};
use serde::{Deserialize, Serialize};

#[derive(Deserialize)]
pub struct CreateUserRequest {
    pub name: String,
    pub email: String,
}

#[derive(Serialize)]
pub struct UserResponse {
    pub success: bool,
    pub message: String,
    pub user_id: Option<String>,
}

#[service_definition]
pub struct UserService;

#[service_impl]
impl UserService {
    #[service_method("POST /users")]
    pub async fn create_user(request: CreateUserRequest) -> Result<UserResponse, String> {
        // JUST YOUR BUSINESS LOGIC!
        println!("Creating user: {}", request.name);
        Ok(UserResponse {
            success: true,
            message: "User created successfully".to_string(),
            user_id: Some("user123".to_string()),
        })
    }

    #[service_method("GET /users/:id")]
    pub async fn get_user(user_id: String) -> Result<UserResponse, String> {
        // Framework auto-extracts user_id from URL path
        println!("Getting user: {}", user_id);
        Ok(UserResponse {
            success: true,
            message: format!("Retrieved user {}", user_id),
            user_id: Some(user_id),
        })
    }
}

And get all this automatically generated:

• ✅ HTTP routes: POST /users, GET /users/:id
• ✅ RabbitMQ RPC handlers: rabbitmesh.UserService.create_user, rabbitmesh.UserService.get_user
• ✅ Service registration methods: UserService::create_service(), UserService::service_name()
• ✅ Route discovery: UserService::get_routes()
• ✅ JSON serialization/deserialization
• ✅ API Gateway integration
• ✅ Service discovery

🎯 Supported Method Patterns

The macros intelligently handle different method signatures:

# use rabbitmesh_macros::{service_definition, service_impl};
# use serde::{Deserialize, Serialize};
# #[derive(Deserialize)] pub struct CreateRequest { pub name: String }
# #[derive(Deserialize)] pub struct UpdateRequest { pub name: String }
# #[derive(Serialize)] pub struct Response { pub success: bool }
# #[service_definition] pub struct MyService;
#[service_impl]
impl MyService {
    // Simple path parameter
    #[service_method("GET /items/:id")]
    async fn get_item(id: String) -> Result<Response, String> {
        // id auto-extracted from URL
        Ok(Response { success: true })
    }

    // Request body
    #[service_method("POST /items")]
    async fn create_item(request: CreateRequest) -> Result<Response, String> {
        // request auto-deserialized from JSON
        Ok(Response { success: true })
    }

    // Path param + request body (tuple)
    #[service_method("PUT /items/:id")]
    async fn update_item(params: (String, UpdateRequest)) -> Result<Response, String> {
        let (id, request) = params;
        Ok(Response { success: true })
    }

    // Multiple path parameters
    #[service_method("GET /users/:user_id/items/:item_id")]
    async fn get_user_item(params: (String, String)) -> Result<Response, String> {
        let (user_id, item_id) = params;
        Ok(Response { success: true })
    }
}