fix: swaps with discounts (#142)

packages/medusa-plugin-brightpearl/src/services/brightpearl.js

@@ -546,7 +546,7 @@ class BrightpearlService extends BaseService {
       },
       rows: await this.getBrightpearlRows({
         region_id: fromOrder.region_id,
-        discounts: [],
+        discounts: fromOrder.discounts,
         tax_rate: fromOrder.tax_rate,
         items: fromSwap.additional_items,
         shipping_methods: fromSwap.shipping_methods,

packages/medusa/src/models/schemas/line-item.js

@@ -15,6 +15,7 @@ export default new mongoose.Schema(
     is_giftcard: { type: Boolean, default: false },
     should_merge: { type: Boolean, default: true },
     has_shipping: { type: Boolean, default: false },
+    no_discount: { type: Boolean, default: false },
 
     // mongoose doesn't allow multi-type validation but this field allows both
     // an object containing:

packages/medusa/src/services/swap.js

@@ -300,6 +300,7 @@ class SwapService extends BaseService {
         title: "Return shipping",
         quantity: 1,
         has_shipping: true,
+        no_discount: true,
         content: {
           unit_price: swap.return_shipping.price,
           quantity: 1,

packages/medusa/src/services/totals.js

@@ -35,7 +35,7 @@ class TotalsService extends BaseService {
    * @param {Cart || Order} object - cart or order to calculate subtotal for
    * @return {int} the calculated subtotal
    */
-  getSubtotal(object) {
+  getSubtotal(object, opts = {}) {
     let subtotal = 0
     if (!object.items) {
       return subtotal
@@ -46,9 +46,16 @@ class TotalsService extends BaseService {
         const temp = _.sumBy(item.content, c => c.unit_price * c.quantity)
         subtotal += temp * item.quantity
       } else {
+        if (opts.excludeNonDiscounts) {
+          if (!item.no_discount) {
             subtotal +=
               item.content.unit_price * item.content.quantity * item.quantity
           }
+        } else {
+          subtotal +=
+            item.content.unit_price * item.content.quantity * item.quantity
+        }
+      }
     })
     return this.rounded(subtotal)
   }
@@ -135,6 +142,13 @@ class TotalsService extends BaseService {
    *    applied discount
    */
   calculateDiscount_(lineItem, variant, variantPrice, value, discountType) {
+    if (lineItem.no_discount) {
+      return {
+        lineItem,
+        variant,
+        amount: 0,
+      }
+    }
     if (discountType === "percentage") {
       return {
         lineItem,
@@ -240,7 +254,7 @@ class TotalsService extends BaseService {
    * @return {int} the total discounts amount
    */
   async getDiscountTotal(cart) {
-    let subtotal = this.getSubtotal(cart)
+    let subtotal = this.getSubtotal(cart, { excludeNonDiscounts: true })
 
     if (!cart.discounts || !cart.discounts.length) {
       return 0