| type Promised<R> = R | PromiseLike<R>; | |
| export type Descriptor<A extends any[], R> = (...args: A) => Promised<R>; | |
| export type Decorator<A extends any[], R> = ( | |
| descriptor: Descriptor<A, R>, | |
| ) => Promised<Descriptor<A, R>>; | |
| export type DescriptorSync<A extends any[], R> = (...args: A) => R; | |
| export type DecoratorSync<A extends any[], R> = ( | |
| descriptor: DescriptorSync<A, R>, | |
| ) => DescriptorSync<A, R>; | |
| /** | |
| * @example | |
| * const decorated = decorate(n => n, increaseBy1, increaseBy2, increaseBy3); | |
| * decorated(1); // => 7 | |
| * @param descriptor | |
| * @param decorators | |
| * @returns a new descriptor wrapped | |
| */ | |
| export const decorate = <A extends any[], R>( | |
| descriptor: Descriptor<A, R>, | |
| ...decorators: Decorator<A, R>[] | |
| ) => { | |
| return async function (this: unknown, ...args: A): Promise<R> { | |
| const newDescriptor = decorators.reduce( | |
| ( | |
| descriptor: Descriptor<A, R>, | |
| decorator: Decorator<A, R>, | |
| ): Descriptor<A, R> => { | |
| return async (...args: A): Promise<R> => { | |
| const nextDescriptor = await Promise.resolve( | |
| decorator.call(this, descriptor), | |
| ); | |
| return await Promise.resolve(nextDescriptor.call(this, ...args)); | |
| }; | |
| }, | |
| descriptor.bind(this), | |
| ); | |
| return await newDescriptor(...args); | |
| }; | |
| }; | |
| /** | |
| * @example | |
| * const decorated = decorate(n => n, increaseBy1, increaseBy2, increaseBy3); | |
| * decorated(1); // => 7 | |
| * @param descriptor | |
| * @param decorators | |
| * @returns a new descriptor wrapped | |
| */ | |
| export const decorateSync = <A extends any[], R>( | |
| descriptor: DescriptorSync<A, R>, | |
| ...decorators: DecoratorSync<A, R>[] | |
| ) => { | |
| return function (this: unknown, ...args: A): R { | |
| const newDescriptor = decorators.reduce( | |
| ( | |
| descriptor: DescriptorSync<A, R>, | |
| decorator: DecoratorSync<A, R>, | |
| ): DescriptorSync<A, R> => { | |
| return (...args: A): R => { | |
| const nextDescriptor = decorator.call(this, descriptor); | |
| return nextDescriptor.call(this, ...args); | |
| }; | |
| }, | |
| descriptor.bind(this), | |
| ); | |
| return newDescriptor(...args); | |
| }; | |
| }; |