函数

不要改变形参的值

onServiceCardAdd({
  currentTarget: {
    dataset: {
      item,
    }
  }
}) {
  const initPrepurchases = this.data.pagePrepurchases ? this.data.pagePrepurchases : this.data.initPrepurchases;
  if (item.limitNumber > 0 && item.count <= item.maxCount) {
    item.limitNumber -= 1;
    item.count += 1;
    this.data.num++;
    initPrepurchases.map(initItem => {
      if (item.id === initItem.id) {
        // initItem的值发生了变化，数据源如果被用在了其他地方就有可能导致逻辑错误
        initItem.count = item.count;
      }
    });
    this.setData({
      num: this.data.num
    });
    const storeId = this.data.storeInfo.id;
    this.requestBookingPrepurchaseMaxCount({storeId, prePurechases: initPrepurchases});
  }
}

// 不建议
this.data.skuList.forEach(item => {item['isSelected'] =  true; });
// 建议
this.data.skuList = this.data.skuList.map(item => ({
  ...item,
  isSelected: true,
}));