🍫 Youmiya

💡 Package youmiya is a set of atom packages of @youmiya/*, including:

• @youmiya/core
• @youmiya/modular

Youmiya is a simple dependency injection (DI) library for Typescript with modern features:

• Supports both decorator style and interface-oriented style
• Works without reflect-metadata support (interface-oriented style)
• On-demand lazy (delayed) instantiation
• Support async module injection
• Supports hierarchical containers
• Circular dependency detection & workaround

And more features are on the way:

• Interceptors like tsyringe
• Injection transform
• Modular system
• Idle-time load & instatiation

Getting Started

Basic Usage (decorator style)

reflect-metadata polyfill is needed for decorator style.

import { injectable, inject, rootContainer } from 'youmiya';

@injectable()
class Foo {
  echo() {
    console.log('foo');
  }
}

@injectable()
class Bar {
  constructor(@inject() private readonly foo: Foo) {}

  echo() {
    this.foo.echo();
    console.log('bar');
  }
}

const bar = rootContainer.resolve(Bar);
bar.echo(); // foobar

Basic Usage (interface-oriented style)

Likes VSCode, works well without reflect-metadata.

foo.ts

import { createProviderIdentifier, rootContainer } from 'youmiya';

// define and export interface
export interface IFoo {
  echo: () => void;
}

// define an identifier for provider
export const IFoo = createProviderIdentifier<IFoo>('Foo');

// implement the class
class FooImpl implements IFoo {
  echo() {
    console.log('foo');
  }
}

// bind provider identifier to implementation
rootContainer.register(Foo).toClass(FooImpl);

bar.ts

import { createProviderIdentifier, rootContainer } from 'youmiya';

import { IFoo } from './foo';

interface IBar {
  echo: () => void;
}

const IBar = createProviderIdentifier<IBar>('Bar');

class BarImpl implements IBar {
  constructor(@IFoo() private readonly foo: IFoo) {}

  echo() {
    this.foo.echo();
    console.log('bar');
  }
}

rootContainer.register(IBar).toClass(BarImpl);

const bar = rootContainer.resolve(IBar);
bar.echo(); // foobar

Prerequisities

Youmiya requires a modern JavaScript engine with support for:

• Map
• Typescript experimentalDecorators

The following requires are depending on your usage:

• Typescript emitDecoratorMetadata and reflect-metadata polyfill
  • *only required if using decorator style
• Promise
  • *only required if using async module provider
• Proxy
  • *only required if using lazy instatiation

If your environment doesn't support one of these you will need to import a shim or polyfill.