🐚 Shellder

A lightweight, Spring-inspired Dependency Injection framework for Rust. "A Crab needs its Shell"

✨ Overview

Shellder brings a modular, ergonomic approach to Rust applications by offering:

• 📦 Dependency Injection via #[component] and #[derive(App)] macros
• ⚙️ Lifecycle Hooks (startup, run, cleanup)
• 🛠️ Compile-time struct injection
• 🧵 Thread-safe container (Arc-based)
• 🔧 Optional lightweight logger

Built for CLI tools, long-running services, or application backends.

🚀 Quick Start

Add Shellder to your project

[dependencies]
shellder = "0.2.5"

Example

use std::sync::Arc;
use shellder::{App, Container, Hooks, Lifecycle};

pub struct Logger;
impl Logger {
    pub fn log(&self, msg: &str) {
        println!("[LOG] {}", msg);
    }
}

#[derive(App)]
pub struct HelloApp {
    #[component]
    logger: Arc<Logger>,
}

impl Hooks for HelloApp {
    fn startup(&self) {
        self.logger.log("Starting up!");
    }

    fn run(&self) {
        self.logger.log("Running...");
    }

    fn cleanup(&self) {
        self.logger.log("Shutting down.");
    }
}

Running this app will automatically inject dependencies and call hooks in order.

🧩 Features in v0.2.5

✅ #[component] macro for auto-registration ✅ #[derive(App)] macro to auto-generate main() ✅ Lifecycle Hooks trait support ✅ Thread-safe singleton container ✅ Optional custom logger ✅ Works without tokio or async runtime

🛠️ Planned Roadmap

• 🔖 Named registration & resolution ("db", "logger")
• 🧪 Test container for mocking dependencies
• 🧬 Config loader (from .toml or .yaml)
• 🧱 Fluent container builder
• 🧩 Macro plugins: #[value], #[config], etc.
• 🧵 Async hook support
• 📁 Workspace support & automatic example runner

💡 Philosophy

Shellder follows a Rust-first vision:

• ✅ Strong compile-time guarantees
• 🧼 Minimal runtime dependencies
• 🛠️ Clean syntax with macros
• 🤝 Integrates well with your architecture

📝 License

Licensed under Apache-2.0.

🤝 Contributing

Bug reports, PRs, and feedback are welcome! Open an issue to discuss enhancements or integrations.

📣 Stay Tuned

Shellder is under active development. Watch the repo for updates on:

• Configuration loading
• DI graphs
• CLI/web framework integrations
• Logging plugins