Gets discount information in the Web Pixel

web_pixel.js

  getTotalShippingDiscount: function (event) {
    const discountApplications = event?.data?.checkout?.discountApplications || [];
    const shippingDiscountApplications = discountApplications.filter(
      (discountApplication) => discountApplication?.targetType === "SHIPPING_LINE"
    );

    const shippingDiscountApplicationsPercentBased =
      shippingDiscountApplications.filter(
        (discountApplication) =>
          typeof discountApplication?.value?.percentage !== "undefined"
      );

    const shippingDiscountApplicationsFixedAmountBased =
      shippingDiscountApplications.filter(
        (discountApplication) =>
          typeof discountApplication?.value?.amount !== "undefined"
      );

    const percentBasedDiscounts =
      shippingDiscountApplicationsPercentBased.reduce(
        (acc, shippingDiscountAllocation) => {
          const percentDiscount = shippingDiscountAllocation?.value?.percentage;
          const totalShippingCost =
            event?.data?.checkout?.shippingLine?.price?.amount;
          const discount = (percentDiscount / 100) * totalShippingCost;
          return acc + Number(discount);
        },
        0
      );

    const fixedBasedDiscounts =
      shippingDiscountApplicationsFixedAmountBased.reduce(
        (acc, shippingDiscountAllocation) => {
          return acc + Number(shippingDiscountAllocation?.value?.amount);
        },
        0
      );

    return percentBasedDiscounts + fixedBasedDiscounts;
  },