Гист для статьи "Еще раз о паттернах проектирования в Javascript es6 (часть 2)"

flyweight.js

class Flyweight {
  constructor(state) {
    this.state = state;
  }
}

class FlyWeightFactory {
  constructor(flyweightsList) {
    this.flyweights = {};
    flyweightsList.forEach((item) => {
      this.flyweights[item.join('_')] = new Flyweight(item);
    });
  }

  getFlyweight(state) {
    const key = state.join('_');

    if (!(key in this.flyweights)) {
      console.log('FlyweightFactory: Не могу найти flyweight, создаю новый.');
      this.flyweights[key] = new Flyweight(state);
    } else {
      console.log('FlyweightFactory: Переиспользую имеющийся flyweight.');
    }

    return this.flyweights[key];
  }

  listFlyweights() {
    const count = Object.keys(this.flyweights).length;
    console.log(`FlyweightFactory: Записано ${count} flyweights:`);
    for (const key in this.flyweights) {
      console.log(key);
    }
  }
}

const testing = () => {
  const computers = new FlyWeightFactory([['Dell', 'Studio XPS', 'Y755P'], ['Dell', 'Studio XPS', 'X997T']]);
  computers.listFlyweights();

  computers.getFlyweight(['Dell', 'Studio XPS', 'Y755P']);
  computers.getFlyweight(['Dell', 'Studio XPS', 'X997T']);
  computers.getFlyweight(['Dell', 'Studio XPS', 'NT777']);
  computers.getFlyweight(['HP', 'Envy', 'CNU883701']);
  computers.getFlyweight(['HP', 'Envy', 'TXU003283']);

  computers.listFlyweights();
};

testing();