fix : cart total_discount

src/modules/Coupon/coupon.service.ts

@@ -209,7 +209,7 @@ class CouponService {
       cartShipmentItem.totalCouponDiscount = discount;
       cartShipmentItem.totalPaymentPrice = cartShipmentItem.totalPaymentPrice - discount;
       userCart.coupon_discount = discount;
-      userCart.total_discount += discount;
+
       coupon.usageCount += 1;
 
       await validCartShipmentItem.save({ session });

src/modules/cart/cart.repository.ts

@@ -310,9 +310,14 @@ class CartRepository extends BaseRepository<ICart> {
           },
           total_discount: {
             $sum: {
-              $subtract: [
-                { $multiply: ["$items.quantity", "$variantDetails.price.retailPrice"] },
-                { $multiply: ["$items.quantity", "$variantDetails.price.selling_price"] },
+              $add: [
+                {
+                  $subtract: [
+                    { $multiply: ["$items.quantity", "$variantDetails.price.retailPrice"] },
+                    { $multiply: ["$items.quantity", "$variantDetails.price.selling_price"] },
+                  ],
+                },
+                { $divide: ["$coupon_discount", { $literal: 1 }] }, // safely adds coupon_discount
               ],
             },
           },

src/modules/cart/cart.service.ts

@@ -25,8 +25,8 @@ class CartService {
   async getCartS(userId: string) {
     const doc = (await this.cartRepo.getCartWithAggregate(userId))[0] as ICart;
     const cart = CartDTO.transformCart(doc);
-
     let cartShipmentItems;
+
     if (doc?._id) {
       cartShipmentItems = await this.cartShipItemRepo.getCartShipmentItems(doc._id.toString());
     }