A simple, versatile, Typescript context container

Installation

npm install @emberworks/context-container

bun add @emberworks/context-container

Basic Usage

// --- context.ts ---
import { createContextContainer } from '@emberworks/context-container';
import { type Database } from './db';
import { type SomeService, createSomeService } from './some-service';
import { type SomeOtherService } from './some-other-service';

type Ctx = {
  db: Database;
  someService: SomeService;
  someOtherService: SomeOtherService;
};

// Due to TS limitations we need to provide a type for the complete container
export const ctx = createContextContainer<Ctx>({
  // Set context properties directly
  someService: (ctx) => createSomeService(ctx, {}),
  // Or dynamically
  db: () => import('./db').then((mod) => mod.db),
  // Even do some weird loading shit
  someOtherService: (ctx) => import('./some-other-service').then(async (mod) =>
    mod.createSomeOtherService(ctx, {}),
  ),
});

// You can optionally preload context items
await ctx.loadItems(); // To load all
await ctx.loadItems(['db', 'someService']) // To load some

// --- some-other-service.ts ---
import { type ContextContainer } from '@emberworks/context-container';

// Define only the context that you need for the service
type Ctx = {
  db: Database;
};

export const createSomeOtherService = (
  ctx: ContextContainer<Ctx>,
  options: {},
) => {
  ...
  // Use the context
  const db = await ctx.getItem('db');
  ...
};

// --- some-root-request-or-job-or-whatever-you-like-really.ts ---
import { ctx } from './context';

export const someRequestHandler = async (req: Request) => {
  ...
  const someService = await ctx.getItem('someService');
  ...
}

Docs

Haven't got there yet, you'll figure it out.