fix(core-flow): invalid update quantity in update line item in cart workflow (#10405)

* fix: invalid update quantity in update line item in cart workflow

* test: update cart workflow test

* fix: rm shallow copy in transform

integration-tests/modules/__tests__/cart/store/cart.workflows.spec.ts

@@ -2036,6 +2036,121 @@ medusaIntegrationTestRunner({
           )
         })
 
+        it("should throw insufficient inventory", async () => {
+          const salesChannel = await scModuleService.createSalesChannels({
+            name: "Webshop",
+          })
+
+          const location = await stockLocationModule.createStockLocations({
+            name: "Warehouse",
+          })
+
+          const [product] = await productModule.createProducts([
+            {
+              title: "Test product",
+              variants: [
+                {
+                  title: "Test variant",
+                },
+              ],
+            },
+          ])
+
+          const inventoryItem = await inventoryModule.createInventoryItems({
+            sku: "inv-1234",
+          })
+
+          await inventoryModule.createInventoryLevels([
+            {
+              inventory_item_id: inventoryItem.id,
+              location_id: location.id,
+              stocked_quantity: 2,
+            },
+          ])
+
+          const priceSet = await pricingModule.createPriceSets({
+            prices: [
+              {
+                amount: 3000,
+                currency_code: "usd",
+              },
+            ],
+          })
+
+          await remoteLink.create([
+            {
+              [Modules.PRODUCT]: {
+                variant_id: product.variants[0].id,
+              },
+              [Modules.PRICING]: {
+                price_set_id: priceSet.id,
+              },
+            },
+            {
+              [Modules.SALES_CHANNEL]: {
+                sales_channel_id: salesChannel.id,
+              },
+              [Modules.STOCK_LOCATION]: {
+                stock_location_id: location.id,
+              },
+            },
+            {
+              [Modules.PRODUCT]: {
+                variant_id: product.variants[0].id,
+              },
+              [Modules.INVENTORY]: {
+                inventory_item_id: inventoryItem.id,
+              },
+            },
+          ])
+
+          let cart = await cartModuleService.createCarts({
+            currency_code: "usd",
+            sales_channel_id: salesChannel.id,
+            items: [
+              {
+                variant_id: product.variants[0].id,
+                quantity: 1,
+                unit_price: 5000,
+                title: "Test item",
+              },
+            ],
+          })
+
+          cart = await cartModuleService.retrieveCart(cart.id, {
+            select: ["id", "region_id", "currency_code"],
+            relations: ["items", "items.variant_id", "items.metadata"],
+          })
+
+          const item = cart.items?.[0]!
+
+          const { errors } = await updateLineItemInCartWorkflow(
+            appContainer
+          ).run({
+            input: {
+              cart_id: cart.id,
+              item_id: item.id,
+              update: {
+                metadata: {
+                  foo: "bar",
+                },
+                quantity: 3,
+              },
+            },
+            throwOnError: false,
+          })
+
+          expect(errors).toEqual([
+            {
+              action: "confirm-item-inventory-as-step",
+              handlerType: "invoke",
+              error: expect.objectContaining({
+                message: `Some variant does not have the required inventory`,
+              }),
+            },
+          ])
+        })
+
         describe("compensation", () => {
           it("should revert line item update to original state", async () => {
             expect.assertions(2)
@@ -2075,7 +2190,6 @@ medusaIntegrationTestRunner({
                 inventory_item_id: inventoryItem.id,
                 location_id: location.id,
                 stocked_quantity: 2,
-                reserved_quantity: 0,
               },
             ])
 

packages/core/core-flows/src/cart/workflows/update-line-item-in-cart.ts

@@ -62,8 +62,8 @@ export const updateLineItemInCartWorkflow = createWorkflow(
 
     validateVariantPricesStep({ variants })
 
-    const items = transform({ item }, ({ item }) => {
+    const items = transform({ input, item }, (data) => {
-      return [item]
+      return [Object.assign(data.item, { quantity: data.input.update.quantity })]
     })
 
     confirmVariantInventoryWorkflow.runAsStep({