Decorators

Highly experimental.

Install

$ npm install @slietar/decorators
$ tsd link # if using TypeScript

Decorators appliance

Name	Class	Method	Parameter	Property	Status
@abstract	✓	✓ (?)	✗	✓ (?)	❋
@animationFrame	✗	✓	✗	✗	◉
@autobind	✓ alias: factorize()	✓	✗	✗	◎
@check	✓ (?)	✓	✗	✓ (?) only: set()	❋
@curry	✗	✓	✗	✗	◎
@defaults	✗	✗	✓	✗	✪
@defaults (extended implementation)	✗	✗	✓	✓ only: set()	❋
@deprecate	✓	✓	✓	✓	✪
@desync or @async	✗	✓	✗	✓	◎
@experiment	✓	✓	✓	✓	◉
@memoize	✗	✓	✗	✗	❋
@nonconfigurable	✗	✓	✗	✓	◎
@nonenumerable	✗	✓	✗	✓	◎
@once	✓	✓	✗	✗	◉
@once (extended implementation)	✓	✓	✗	✓	❋
@readonly or @nonwritable	✗	✓	✗	✓	◎
@serialize	✓	✗ (?)	✗	✗ (?)	❋
@stage	✓	✓	✓	✓	❋

❖ ..., ❋ not confirmed, ◎ not implemented, ◉ implemented, ✪ tested (coverage 100%) and fully typed

Maybe:

• @promise: Q(r) if !isPromise(r) (Method, Property (?))

Usage

@deprecate()

@deprecate()
class A {
  @deprecate()
  p;

  @deprecate('Custom message')
  m() { }

  n(a, @deprecate(void 0, customLogger) b) { }
}

let a = new A() // on console.warn - DEPRECATION A: This feature is deprecated and will be removed in future versions
a.m(); // DEPRECATION A#m(): Custom message

a.n('1'); // nothing
a.n('1', '2') // on customLogger.warn - DEPRECATION A#n(1): ...

a.p; // DEPRECATION A#p: ...
a.p = 3; // nothing

Notes on @desync

On method:

class A {
  @desync(done => setTimeout(done, 500)) // same as @debounce(500)
  b() {

  }
}

On parameter:

class Auth {
  save(@desync() user) {
    this.user = user;
  }
}

var a = new Auth();

a.save(getPromise());

Notes on @serialize

@serialize()
class A {
  constructor() {
    this.a = 42;
  }

  getA() {
    return this.a;
  }
}

let json = JSON.stringify(new A());
// => { constructor: 'A', properties: { a: 42 } }

let parsed = JSON.parse(json);
let obj = A.fromJSON(parsed);
// => { a: 42, getA: [Function: getA] } }

@serialize()
class A {
  @serialize()
  a = 'John Doe';

  @nonserializable()
  b = 42;

  //        (     stringify     ) (       parse       )
  @serialize(c => c.toUpperCase(), c => c.toLowerCase())
  c = 'lorem ipsum';
}

new A()
  .__serializeProperties = {
    a: true,
    b: false,
    c: { serialize: [Fn], deserialize: [Fn] }
  };

TypeScript definitions

declare type ClassDecorator = <TFunction extends Function>(target: TFunction) => TFunction | void;
declare type PropertyDecorator = (target: Object, propertyKey: string | symbol) => void;
declare type MethodDecorator = <T>(target: Object, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T> | void;
declare type ParameterDecorator = (target: Function, propertyKey: string | symbol, parameterIndex: number) => void;