@injets/core

A lightweight dependency injection library for Node.js and TypeScript.

Installation

npm install @injets/core

Usage

import { Container } from '@injets/core';

class MyService {
  constructor() {
    console.log('MyService constructed');
  }

  method() {
    console.log('MyService method');
  }
}

const container = new Container();

container.provide({
  token: 'myService',
  useClass: MyService,
})

const myService = container.resolve('myService');

API

Container

constructor(options: ContainerOptions = {})

Creates a new container instance.

provide<T>(provider: Provider<T>): void

Registers a provider in the container.

resolve<T>(token: Token<T>): T

Resolves a provider from the container.

resolve<T extends Token[]>(tokens: T): DependencyValues<T>

Resolves multiple providers from the container.

import(container: Container): void

Imports all exported providers from another container.

export(token: Token): void

Exports a provider from the container.

Provider

Exists many types of providers:

ClassProvider<T>

Provide a instance of a class.

interface ClassProvider<T> {
  token: Token<T>;
  useClass: Class<T>;
  mode?: ProviderMode;
}

FactoryProvider<T>

Provide a value of a factory.

interface FactoryProvider<T> {
  token: Token<T>;
  useFactory: Factory<T>;
  mode?: ProviderMode;
}

ValueProvider<T>

Provide a value.

interface ValueProvider<T> {
  token: Token<T>;
  useValue: T;
  mode?: ProviderMode;
}

Options

ContainerOptions

Options for the container.

interface ContainerOptions {
  isGlobal?: boolean;
  imports?: Container[];
  providers?: Provider[];
  exports?: Token[];
}

ProviderMode

Mode of the provider.

enum ProviderMode {
  SINGLETON = 'SINGLETON',
  TRANSIENT = 'TRANSIENT',
}

Provider

A provider can be a class, a factory or a value.

type Provider<T> = ClassProvider<T> | FactoryProvider<T> | ValueProvider<T>;

Token<T>

A token is a unique identifier for a provider.

type Token<T = any> = string | symbol | Class<T>;

Other packages

• @injets/functional - Support for functional programming in JavaScript and TypeScript.
• @injets/decorators - Support for decorators in TypeScript.