spark-edge-di — Dependency Injection Container

A lightweight, type-safe Dependency Injection (DI) library for Node.js and TypeScript, designed to handle automatic dependency resolution via decorators and reflect-metadata.

Used internally by Spark Edge to power its modular architecture and decouple core services.

🏗️ Features

• Decorator-based: Register dependencies using the @Service() class decorator.
• Constructor Injection: Automatically resolves and injects constructor parameters using runtime metadata.
• Factory Support: Define custom instantiation logic for complex services using factories.
• Circular Dependency Detection: Prevents runtime deadlocks and provides clear dependency path traces.
• Singleton Instances: Reuses instantiated objects throughout the lifetime of the container.
• Abstract Classes: Supports mapping abstract classes to concrete implementations manually.

🚀 Usage

1. Enable decorators in tsconfig.json

Ensure your TypeScript configuration has experimental decorators and metadata enabled:

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

2. Define Injectable Services

import { Service, Container } from 'spark-edge-di';

@Service()
class Logger {
  log(message: string) {
    console.log(`[LOG]: ${message}`);
  }
}

@Service()
class DatabaseService {
  constructor(private logger: Logger) {}

  query(sql: string) {
    this.logger.log(`Running: ${sql}`);
  }
}

// Retrieve instance from the container
const db = Container.get(DatabaseService);
db.query("SELECT * FROM users");