/// 属性装饰器

import 'reflect-metadata';

const formatMetadataKey = Symbol('format');

function format(formatString: string) {
  return (
    target, // 指向实例原型
    propertyKey // 指向属性名称
  ) => {
    console.info({ target, propertyKey });

    return Reflect.metadata(formatMetadataKey, formatString)(
      target,
      propertyKey
    );
  };
}

class Animal {
  @format('Hello, %s')
  message: string;

  constructor() {
    this.message = 'message';
  }

  call() {
    const formatString = Reflect.getMetadata(
      formatMetadataKey,
      this,
      'message'
    );

    console.log(formatString.replace('%s', this.message));
  }
}

const ani = new Animal();

ani.call();

export default Animal;