Assessment Kata from GildedRose Refactoring

gilded_rose_new.js

const itemQualityFunctionIndex = {
  "Aged Brie": function(item) {
    item.quality++;
    return item
  },

  "Backstage passes": function (item) {
    if (item.sellIn <= 10 && item.sellIn > 5) {
      item.quality += 2;
    } else if (item.sellIn <= 5 && item.sellIn > -1) {
      item.quality += 3;
    } else if (item.sellIn < 0) {
      item.quality = 0;
    }
    return item
  },

  "Sulfuras": function (item) {
    return item;
  },

  "normal": function (item) {
    if (item.conjured == true) {
      if (item.sellIn < 0) {
        item.quality -= 4;
      } else {
        item.quality -= 2;
      }

    } else {
      if (item.sellIn < 0) {
        item.quality -= 2;
      } else {
        item.quality --;
      }
    }
    return item
  }
}


class Item {
  constructor(name, sellIn, quality, conjured){
    this.name = name;
    this.sellIn = sellIn;
    this.quality = quality;
    this.conjured = conjured;
  }
}

class Shop {
  constructor(items=[]){
    this.items = items;
  }

  updateQuality() {
    for (var i = 0; i < this.items.length; i++) {
      let item = this.items[i];
      item = updateItemQuality(item);


      item.sellIn = item.sellIn --;
      if ((item.quality > 50) && (item.name != "Sulfuras")) {
        item.quality = 50;
      }
      if (item.quality < 0) {
        item.quality = 0;
      }
  } // end for loop
    return this.items;
  } // end updateQuality
} // end class Sho


module.exports = {
  Item,
  Shop
}


function updateItemQuality(item) {
  if (Object.keys(itemQualityFunctionIndex).indexOf(item.name) > -1) {
    return itemQualityFunctionIndex[item.name](item)
  } else {
    return itemQualityFunctionIndex.normal(item)
  }
}

test_gilded_rose.js

var {expect} = require('chai');
var {Shop, Item} = require('../src/gilded_rose_new.js');
var c = console.log.bind(console);

describe("Gilded Rose", function() {

  it("Should work", function() {
    const gildedRose = new Shop([
      new Item("Aged Brie", 5, 30, false),
      new Item("Backstage passes", 8, 20, false),
      new Item("Stamps", 10, 14, true),
      new Item("Backstage passes", 2, 90, false),
      new Item("Backstage passes", 2, 30, false),
      new Item("Stamps", -3, 14, true),
    ]);

    const items = gildedRose.updateQuality();

    expect(items[0].quality).to.equal(31);
    expect(items[1].quality).to.equal(22);
    expect(items[2].quality).to.equal(12);
    expect(items[3].quality).to.equal(50);
    expect(items[4].quality).to.equal(33);
    expect(items[5].quality).to.equal(10);

  });

});