feat(medusa, types, utils, core-flows, order) request & accept order transfer (#10106)

**What**
- add request order transfer workflow
- add admin endpoint for transferring an order to a customer
- accept order transfer storefront endpoint
- accept transfer workflow
- changes in the order module to introduce new change and action types

---

**Note**
- we return 400 instead 409 currently if there is already an active order edit, I will revisit this in a followup
- endpoint for requesting order transfer from the storefront will be added in a separate PR

---

RESOLVES CMRC-701
RESOLVES CMRC-703
RESOLVES CMRC-704
RESOLVES CMRC-705

packages/modules/order/src/types/utils/index.ts

@@ -56,6 +56,8 @@ export type VirtualOrder = {
 
   total: BigNumberInput
 
+  customer_id?: string
+
   transactions?: OrderTransaction[]
   metadata?: Record<string, unknown>
 }

packages/modules/order/src/utils/actions/index.ts

@@ -13,3 +13,4 @@ export * from "./ship-item"
 export * from "./shipping-add"
 export * from "./shipping-remove"
 export * from "./write-off-item"
+export * from "./transfer-customer"

packages/modules/order/src/utils/actions/transfer-customer.ts

@@ -0,0 +1,19 @@
+import { ChangeActionType, MedusaError } from "@medusajs/framework/utils"
+import { OrderChangeProcessing } from "../calculate-order-change"
+import { setActionReference } from "../set-action-reference"
+
+OrderChangeProcessing.registerActionType(ChangeActionType.TRANSFER_CUSTOMER, {
+  operation({ action, currentOrder, options }) {
+    currentOrder.customer_id = action.reference_id
+
+    setActionReference(currentOrder, action, options)
+  },
+  validate({ action }) {
+    if (!action.reference_id) {
+      throw new MedusaError(
+        MedusaError.Types.INVALID_DATA,
+        "Reference to customer ID is required"
+      )
+    }
+  },
+})

packages/modules/order/src/utils/apply-order-changes.ts

@@ -27,6 +27,13 @@ export function applyChangesToOrder(
   const summariesToUpsert: any[] = []
   const orderToUpdate: any[] = []
 
+  const orderEditableAttributes = [
+    "customer_id",
+    "sales_channel_id",
+    "email",
+    "no_notification",
+  ]
+
   const calculatedOrders = {}
   for (const order of orders) {
     const calculated = calculateOrderChange({
@@ -41,6 +48,17 @@ export function applyChangesToOrder(
     calculatedOrders[order.id] = calculated
 
     const version = actionsMap[order.id]?.[0]?.version ?? order.version
+    const orderAttributes: {
+      version?: number
+      customer_id?: string
+    } = {}
+
+    // Editable attributes that have changed
+    for (const attr of orderEditableAttributes) {
+      if (order[attr] !== calculated.order[attr]) {
+        orderAttributes[attr] = calculated.order[attr]
+      }
+    }
 
     for (const item of calculated.order.items) {
       if (MathBN.lte(item.quantity, 0)) {
@@ -113,12 +131,16 @@ export function applyChangesToOrder(
         }
       }
 
+      orderAttributes.version = version
+    }
+
+    if (Object.keys(orderAttributes).length > 0) {
       orderToUpdate.push({
         selector: {
           id: order.id,
         },
         data: {
-          version,
+          ...orderAttributes,
         },
       })
     }