@bulatlib/di — A simple dependency injection container

Install

npm i @bulatlib/di
# or
pnpm add @bulatlib/di
# or
bun add @bulatlib/di

Quick start

import { p, init } from '@bulatlib/di';

const createApi = () => {
  return {
    ping: () => 'pong',
  };
};

const createService = (api: { ping: () => string } = di.api.get()) => {
  return {
    run: () => api.ping(),
  };
};

const di = init(
  {
    api: p(() => createApi()),
    service: p(() => createService()),
  },
  {
    onBind: (name) => console.log('binding:', name),
  },
);

// binding: di.service
// binding: di.api

console.log(di.service.get().run());
// pong

Override in tests

You can rebind any provider before the first .get():

let di = init({ api: p(() => new Api()) });
di.api.bind(() => new MockApi());
const api = di.api.get();

API

• p(() => T): create a provider of T.
• init(deps, { initialKey = 'di', onBind? }) → returns initialized deps.
• Provider.bind(builder?): bind with optional custom factory.
• Provider.get(): get a singleton instance.

Notes:

• All providers are singletons by default.
• No decorators or reflect-metadata are required.