javascript - 计算State数量——重构

Question

我实现了一个逻辑来通过data变量计算剩余数量和成本。它循环遍历每个产品，并通过计算已返回数量状态的数量来计算剩余数量，并减去产品数量。

有没有办法重构这段代码，使其看起来更干净、易于理解/可维护？我不喜欢我必须这样做: obj[productItem.ProductId] ，它看起来有点难看。

const data = {Products: [{ProductId: 123,Qty: 5,Price: 50,State: [{Name: "Returned",Qty: 1},{Name: "Returned",Qty: 3}]},{ProductId: 123,Qty: 2,Price: 20,State:[{Name: "Returned",Qty: 1}]}]};


function getRemainingQty(order) {
    return order.Products.reduce((obj, productItem) => {
      let productStates = [];
  
      if (productItem.State) {
        productStates = productItem.State;
      }
      
      let returnedQty = productStates.reduce((quantity, productState) => {
        return productState.Name === "Returned" ? quantity + productState.Qty : quantity;
      }, 0);
  
      let returnRemainingQty = productItem.Qty - returnedQty;
      let returnAmountCost =  productItem.Price / productItem.Qty * returnRemainingQty;
  
      if (obj[productItem.ProductId]) {
        obj[productItem.ProductId].QtyRemaining += returnRemainingQty;
        obj[productItem.ProductId].ReturnCostRemaining += returnAmountCost;
      } else {
        obj[productItem.ProductId] = {
          QtyRemaining: returnRemainingQty,
          ReturnCostRemaining: returnAmountCost
        };
      }
  
      return obj;
    }, {});
  }


  console.log(getRemainingQty(data));

Answer 1

这里有一些想法，使用解构、 bool ||、过滤器、...:

const data = {Products: [{ProductId: 123,Qty: 5,Price: 50,State: [{Name: "Returned",Qty: 1},{Name: "Returned",Qty: 3}]},{ProductId: 123,Qty: 2,Price: 20,State:[{Name: "Returned",Qty: 1}]}]};

function getRemainingQty(order) {
    return order.Products.reduce((obj, { ProductId, Qty, Price, State } ) => {
        const returnedQty = (State || [])
              .filter(({ Name }) => Name === "Returned")
              .reduce((quantity, { Qty }) => quantity + Qty, 0);      
        const productStock = obj[ProductId] || (obj[ProductId] = {
            QtyRemaining: 0,
            ReturnCostRemaining: 0
        });
        const returnRemainingQty = Qty - returnedQty;
        productStock.QtyRemaining += returnRemainingQty;
        productStock.ReturnCostRemaining += Price / Qty * returnRemainingQty;
        return obj;
    }, {});
}

console.log(getRemainingQty(data));