simple-inject

A lightweight dependency injection tool for TypeScript projects (Actually not so powerful).

中文版本

Installation

npm install simple-inject

Features

• Simple API with provide and inject functions
• Support for namespaces to manage dependencies in different contexts
• Lightweight and flexible, suitable for small to medium-sized projects
• No external dependencies
• TypeScript support with generics for type safety

Usage

import { provide, inject } from 'simple-inject';

// Provide a dependency
provide('config', { apiUrl: 'https://api.example.com' });

// Inject a dependency
const config = inject<{ apiUrl: string }>('config');
console.log(config?.apiUrl); // https://api.example.com

// Using namespaces
const appNamespace = Symbol('app');
provide('logger', console.log, appNamespace);
const logger = inject<typeof console.log>('logger', appNamespace);
logger?.('Hello, world!'); // Hello, world!

API

provide(key: string, value: any, namespace?: string | symbol)

Registers a dependency with the given key and value. Optionally, you can specify a namespace.

inject(key: string, namespace?: string | symbol): T | undefined

Retrieves a dependency with the given key. Optionally, you can specify a namespace. Returns undefined if the dependency is not found.

DependencyContainer

A class that manages dependencies. You can create multiple instances if needed:

import { DependencyContainer } from 'simple-inject';

const container = new DependencyContainer();
container.provide('db', dbConnection);
const db = container.inject('db');

When to use simple-inject

• For small to medium-sized projects that need a straightforward way to manage dependencies
• When you want to avoid the complexity of full-fledged DI frameworks
• In scenarios where you need a flexible, lightweight solution for dependency management
• For projects that prioritize simplicity and ease of use over advanced DI features

Limitations

• Does not support automatic injection or decoration of classes/functions
• No built-in lifecycle management for dependencies
• Limited features compared to full-scale DI frameworks

License

MIT