feat(core-flows,types,utils,medusa): Update existing line items when adding the same variant to cart (#7470)

* feat(core-flows,types,utils,medusa): Update existing line items when adding the same variant to cart

* chore: split steps into 2 for add-to-cart

* chore: split steps into 2 for add-to-cart

* chore: iterate safely

* chore: parallelize upsert

packages/core/core-flows/src/definition/cart/steps/add-to-cart.ts

@@ -1,31 +0,0 @@
-import { ModuleRegistrationName } from "@medusajs/modules-sdk"
-import { CreateLineItemForCartDTO, ICartModuleService } from "@medusajs/types"
-import { StepResponse, createStep } from "@medusajs/workflows-sdk"
-
-interface StepInput {
-  items: CreateLineItemForCartDTO[]
-}
-
-export const addToCartStepId = "add-to-cart-step"
-export const addToCartStep = createStep(
-  addToCartStepId,
-  async (data: StepInput, { container }) => {
-    const cartService = container.resolve<ICartModuleService>(
-      ModuleRegistrationName.CART
-    )
-
-    const items = await cartService.addLineItems(data.items)
-
-    return new StepResponse(items, items)
-  },
-  async (createdLineItems, { container }) => {
-    const cartService: ICartModuleService = container.resolve(
-      ModuleRegistrationName.CART
-    )
-    if (!createdLineItems?.length) {
-      return
-    }
-
-    await cartService.deleteLineItems(createdLineItems.map((c) => c.id))
-  }
-)

packages/core/core-flows/src/definition/cart/steps/create-line-items.ts

@@ -0,0 +1,35 @@
+import { ModuleRegistrationName } from "@medusajs/modules-sdk"
+import { CreateLineItemForCartDTO, ICartModuleService } from "@medusajs/types"
+import { createStep, StepResponse } from "@medusajs/workflows-sdk"
+
+interface StepInput {
+  id: string
+  items: CreateLineItemForCartDTO[]
+}
+
+export const createLineItemsStepId = "create-line-items-step"
+export const createLineItemsStep = createStep(
+  createLineItemsStepId,
+  async (data: StepInput, { container }) => {
+    const cartModule = container.resolve<ICartModuleService>(
+      ModuleRegistrationName.CART
+    )
+
+    const createdItems = data.items.length
+      ? await cartModule.addLineItems(data.items)
+      : []
+
+    return new StepResponse(createdItems, createdItems)
+  },
+  async (createdItems, { container }) => {
+    if (!createdItems?.length) {
+      return
+    }
+
+    const cartModule: ICartModuleService = container.resolve(
+      ModuleRegistrationName.CART
+    )
+
+    await cartModule.deleteLineItems(createdItems.map((c) => c.id))
+  }
+)

packages/core/core-flows/src/definition/cart/steps/get-line-item-actions.ts

@@ -0,0 +1,59 @@
+import { ModuleRegistrationName } from "@medusajs/modules-sdk"
+import {
+  CartLineItemDTO,
+  CreateLineItemForCartDTO,
+  ICartModuleService,
+  UpdateLineItemWithSelectorDTO,
+} from "@medusajs/types"
+import { deepEqualObj, isPresent, MathBN } from "@medusajs/utils"
+import { createStep, StepResponse } from "@medusajs/workflows-sdk"
+
+interface StepInput {
+  id: string
+  items: CreateLineItemForCartDTO[]
+}
+
+export const getLineItemActionsStepId = "get-line-item-actions-step"
+export const getLineItemActionsStep = createStep(
+  getLineItemActionsStepId,
+  async (data: StepInput, { container }) => {
+    const cartModule = container.resolve<ICartModuleService>(
+      ModuleRegistrationName.CART
+    )
+
+    const existingVariantItems = await cartModule.listLineItems({
+      cart_id: data.id,
+      variant_id: data.items.map((d) => d.variant_id!),
+    })
+
+    const variantItemMap = new Map<string, CartLineItemDTO>(
+      existingVariantItems.map((item) => [item.variant_id!, item])
+    )
+
+    const itemsToCreate: CreateLineItemForCartDTO[] = []
+    const itemsToUpdate: UpdateLineItemWithSelectorDTO[] = []
+
+    for (const item of data.items) {
+      const existingItem = variantItemMap.get(item.variant_id!)
+      const metadataMatches =
+        (!isPresent(existingItem?.metadata) && !isPresent(item.metadata)) ||
+        deepEqualObj(existingItem?.metadata, item.metadata)
+
+      if (existingItem && metadataMatches) {
+        const quantity = MathBN.sum(
+          existingItem.quantity as number,
+          item.quantity || 1
+        ).toNumber()
+
+        itemsToUpdate.push({
+          selector: { id: existingItem.id },
+          data: { id: existingItem.id, quantity: quantity },
+        })
+      } else {
+        itemsToCreate.push(item)
+      }
+    }
+
+    return new StepResponse({ itemsToCreate, itemsToUpdate }, null)
+  }
+)

packages/core/core-flows/src/definition/cart/steps/index.ts

@@ -1,8 +1,8 @@
 export * from "./add-shipping-method-to-cart"
-export * from "./add-to-cart"
 export * from "./confirm-inventory"
 export * from "./create-carts"
 export * from "./create-line-item-adjustments"
+export * from "./create-line-items"
 export * from "./create-order-from-cart"
 export * from "./create-shipping-method-adjustments"
 export * from "./find-one-or-any-region"
@@ -10,6 +10,7 @@ export * from "./find-or-create-customer"
 export * from "./find-sales-channel"
 export * from "./get-actions-to-compute-from-promotions"
 export * from "./get-item-tax-lines"
+export * from "./get-line-item-actions"
 export * from "./get-promotion-codes-to-apply"
 export * from "./get-variant-price-sets"
 export * from "./get-variants"
@@ -22,6 +23,7 @@ export * from "./retrieve-cart-with-links"
 export * from "./set-tax-lines-for-items"
 export * from "./update-cart-promotions"
 export * from "./update-carts"
+export * from "./update-line-items"
 export * from "./validate-cart-payments"
 export * from "./validate-cart-shipping-options"
 export * from "./validate-variant-prices"

packages/core/core-flows/src/definition/cart/steps/update-line-items.ts

@@ -0,0 +1,64 @@
+import { ModuleRegistrationName } from "@medusajs/modules-sdk"
+import {
+  ICartModuleService,
+  UpdateLineItemWithSelectorDTO,
+} from "@medusajs/types"
+import { getSelectsAndRelationsFromObjectArray } from "@medusajs/utils"
+import { createStep, StepResponse } from "@medusajs/workflows-sdk"
+
+interface StepInput {
+  id: string
+  items: UpdateLineItemWithSelectorDTO[]
+}
+
+export const updateLineItemsStepId = "update-line-items-step"
+export const updateLineItemsStep = createStep(
+  updateLineItemsStepId,
+  async (input: StepInput, { container }) => {
+    const { id, items = [] } = input
+
+    if (!items?.length) {
+      return new StepResponse([], [])
+    }
+
+    const cartModule = container.resolve<ICartModuleService>(
+      ModuleRegistrationName.CART
+    )
+
+    const { selects, relations } = getSelectsAndRelationsFromObjectArray(
+      items.map((item) => item.data)
+    )
+
+    const itemsBeforeUpdate = await cartModule.listLineItems(
+      { id: items.map((d) => d.selector.id!) },
+      { select: selects, relations }
+    )
+
+    const updatedItems = items.length
+      ? await cartModule.updateLineItems(items)
+      : []
+
+    return new StepResponse(updatedItems, itemsBeforeUpdate)
+  },
+  async (itemsBeforeUpdate, { container }) => {
+    if (!itemsBeforeUpdate?.length) {
+      return
+    }
+
+    const cartModule: ICartModuleService = container.resolve(
+      ModuleRegistrationName.CART
+    )
+
+    if (itemsBeforeUpdate.length) {
+      const itemsToUpdate: UpdateLineItemWithSelectorDTO[] = []
+
+      for (const item of itemsBeforeUpdate) {
+        const { id, ...data } = item
+
+        itemsToUpdate.push({ selector: { id }, data })
+      }
+
+      await cartModule.updateLineItems(itemsToUpdate)
+    }
+  }
+)

packages/core/core-flows/src/definition/cart/workflows/add-to-cart.ts

@@ -5,10 +5,16 @@ import {
 import {
   WorkflowData,
   createWorkflow,
+  parallelize,
   transform,
 } from "@medusajs/workflows-sdk"
 import { useRemoteQueryStep } from "../../../common/steps/use-remote-query"
-import { addToCartStep, refreshCartShippingMethodsStep } from "../steps"
+import {
+  createLineItemsStep,
+  getLineItemActionsStep,
+  refreshCartShippingMethodsStep,
+  updateLineItemsStep,
+} from "../steps"
 import { refreshCartPromotionsStep } from "../steps/refresh-cart-promotions"
 import { updateTaxLinesStep } from "../steps/update-tax-lines"
 import { validateVariantPricesStep } from "../steps/validate-variant-prices"
@@ -78,7 +84,25 @@ export const addToCartWorkflow = createWorkflow(
       return items
     })
 
-    const items = addToCartStep({ items: lineItems })
+    const { itemsToCreate = [], itemsToUpdate = [] } = getLineItemActionsStep({
+      id: input.cart.id,
+      items: lineItems,
+    })
+
+    const [createdItems, updatedItems] = parallelize(
+      createLineItemsStep({
+        id: input.cart.id,
+        items: itemsToCreate,
+      }),
+      updateLineItemsStep({
+        id: input.cart.id,
+        items: itemsToUpdate,
+      })
+    )
+
+    const items = transform({ createdItems, updatedItems }, (data) => {
+      return [...(data.createdItems || []), ...(data.updatedItems || [])]
+    })
 
     const cart = useRemoteQueryStep({
       entry_point: "cart",
@@ -88,9 +112,7 @@ export const addToCartWorkflow = createWorkflow(
     }).config({ name: "refetch–cart" })
 
     refreshCartShippingMethodsStep({ cart })
-    // TODO: since refreshCartShippingMethodsStep potentially removes cart shipping methods, we need the updated cart here
-    // for the following 2 steps as they act upon final cart shape
-    updateTaxLinesStep({ cart_or_cart_id: cart, items })
+    updateTaxLinesStep({ cart_or_cart_id: input.cart.id, items })
     refreshCartPromotionsStep({ id: input.cart.id })
     refreshPaymentCollectionForCartStep({ cart_id: input.cart.id })
 

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

@@ -5,7 +5,7 @@ import {
   transform,
 } from "@medusajs/workflows-sdk"
 import { useRemoteQueryStep } from "../../../common/steps/use-remote-query"
-import { updateLineItemsStep } from "../../line-item/steps"
+import { updateLineItemsStepWithSelector } from "../../line-item/steps"
 import { refreshCartShippingMethodsStep } from "../steps"
 import { refreshCartPromotionsStep } from "../steps/refresh-cart-promotions"
 import { validateVariantPricesStep } from "../steps/validate-variant-prices"
@@ -77,7 +77,7 @@ export const updateLineItemInCartWorkflow = createWorkflow(
       }
     })
 
-    const result = updateLineItemsStep(lineItemUpdate)
+    const result = updateLineItemsStepWithSelector(lineItemUpdate)
 
     const cart = useRemoteQueryStep({
       entry_point: "cart",

packages/core/core-flows/src/definition/line-item/steps/update-line-items.ts

@@ -10,9 +10,10 @@ import {
 } from "@medusajs/utils"
 import { StepResponse, createStep } from "@medusajs/workflows-sdk"
 
-export const updateLineItemsStepId = "update-line-items"
-export const updateLineItemsStep = createStep(
-  updateLineItemsStepId,
+export const updateLineItemsStepWithSelectorId =
+  "update-line-items-with-selector"
+export const updateLineItemsStepWithSelector = createStep(
+  updateLineItemsStepWithSelectorId,
   async (input: UpdateLineItemWithSelectorDTO, { container }) => {
     const service = container.resolve<ICartModuleService>(
       ModuleRegistrationName.CART