@signe/di

A lightweight and flexible dependency injection system for JavaScript/TypeScript applications.

Installation

npm install @signe/di
# or
yarn add @signe/di
# or
pnpm add @signe/di

Features

• Simple and intuitive API
• Type-safe dependency injection
• Provider system with multiple configuration options
• Context-based injection
• Override capabilities for testing and customization
• Support for nested providers

Usage

Basic Usage

import { provide, inject, Context, Providers } from '@signe/di';

const context = new Context();

class UserService {
  getUser(id: string) {
    return { id, name: 'John Doe' };
  }
}

class AuthService {
  constructor(private config: any) {}
}

const providers: Providers = [
  UserService,
  {
    provide: 'CONFIG',
    useValue: {
      apiUrl: 'https://api.example.com'
    }
  },
  {
    provide: AuthService,
    useFactory: (context) => {
      const config = inject(context, 'CONFIG');
      return new AuthService(config);
    }
  }
];

// Provide the service
provide(context, providers);

// Inject and use the service
const userService = inject(context, UserService);
const user = userService.getUser('123');

Override Providers

import { override } from '@signe/di';

// Override existing provider
const newProviders = override(providers, {
  provide: UserService,
  useValue: new MockUserService()
});

// Add new provider with upsert option
const updatedProviders = override(providers, {
  provide: 'NEW_SERVICE',
  useValue: service
}, { upsert: true });

Check Injection Status

import { isInjected } from '@signe/di';

if (isInjected(context, UserService)) {
  // Service is already injected
}

Find Providers

import { findProvider, findProviders } from '@signe/di';

// Find single provider
const userProvider = findProvider(providers, UserService);

// Find multiple providers by regex
const allServices = findProviders(providers, /Service$/);

API Reference

provide(context, key, value)

Stores a value in the context for dependency injection.

inject(context, key)

Retrieves an injected value from the context.

isInjected(context, key)

Checks if a value has been injected.

override(providers, newProvider, options?)

Overrides or adds new providers to the existing provider array.

findProvider(providers, query)

Finds a single provider by name or regex.

findProviders(providers, query)

Finds all providers matching the query.

License

MIT © Samuel Ronce