Run results for: lodash vs Map - v2

Test name	Executions per second
✓ Map - v2	5,582,452 Ops/sec
Map	4,115,513 Ops/sec
lodash	559,474 Ops/sec

Map

function consolidateCartItems({ items }) {
    const uniqItemsMap = items.reduce((acc, item) => {
      const prevItem = acc.get(item.goodsCode);
      if (prevItem) {
        const options = (prevItem.options ?? []).concat(item?.options ?? []);
        const hasOptions = options.length > 0;
        const newItem = {
          ...prevItem,
          quantity: prevItem.quantity + item.quantity,
        };

        if (hasOptions) {
          newItem.options = consolidateCartItems({ items: options });
        }
        acc.set(item.goodsCode, newItem);
      } else {
        acc.set(item.goodsCode, item);
      }
      return acc;
    }, new Map());

    return [...uniqItemsMap.values()];
  }

consolidateCartItems(body)

Map - v2

function consolidateCartItems({ items }) {
  const map = new Map();

  for (const item of items) {
    const key = item.goodsCode;
    const existing = map.get(key);

    if (existing) {
      existing.quantity += item.quantity;

      const mergedOptions = mergeOptions(existing.options ?? [], item.options ?? []);
      if (mergedOptions.length > 0) {
        existing.options = consolidateCartItems({ items: mergedOptions });
      }
    } else {
      map.set(key, { ...item });
    }
  }

  return [...map.values()];
}

function mergeOptions(a, b) {
  return [...a, ...b];
}
             
consolidateCartItems(body)

lodash

function consolidateCartItems({ items }) {
    return (
      _.chain(items)
        // goodsCode를 기준으로 그룹화
        .groupBy('goodsCode')
        .map((group, goodsCode) => {
          // 그룹 내 전체 수량 합산
          const quantity = _.sumBy(group, 'quantity');

          // 옵션들을 한 곳에 모은 후 존재 여부 확인
          const mergedOptions = _.chain(group)
            .flatMap('options') // 모든 옵션을 평탄화
            .filter(Boolean) // null/undefined 필터링
            .thru((opts) =>
              opts.length > 0
                ? consolidateCartItems({ items: opts }) // 재귀 병합
                : undefined,
            )
            .value();

          // 병합된 항목 생성 (옵션은 있을 경우에만 포함)
          return {
            goodsCode,
            quantity,
            ...(mergedOptions ? { options: mergedOptions } : {}),
          };
        })
        .value()
    );
  }
             
consolidateCartItems(body)