feat: prevent refunding cancelled pos orders on both server and client side

models/pos_order.py

@@ -1,4 +1,5 @@
-from odoo import models, fields, api
+from odoo import models, fields, api, _
+from odoo.exceptions import UserError
 
 class PosOrder(models.Model):
     _inherit = 'pos.order'
@@ -8,3 +9,9 @@ class PosOrder(models.Model):
     # Existing Odoo/POS fields renamed for clarity
     user_id = fields.Many2one('res.users', string='Session User', help='Odoo user who opened the session')
     employee_id = fields.Many2one('hr.employee', string='Order Taker', help='Employee who uses the cash register')
+
+    def _refund(self):
+        for order in self:
+            if order.state == 'cancel':
+                raise UserError(_("You cannot refund a cancelled order."))
+        return super()._refund()

static/src/app/screens/ticket_screen/ticket_screen.js

@@ -2,6 +2,8 @@
 
 import { patch } from "@web/core/utils/patch";
 import { TicketScreen } from "@point_of_sale/app/screens/ticket_screen/ticket_screen";
+import { AlertDialog } from "@web/core/confirmation_dialog/confirmation_dialog";
+import { _t } from "@web/core/l10n/translation";
 
 patch(TicketScreen.prototype, {
     async setOrder(order) {
@@ -25,5 +27,17 @@ patch(TicketScreen.prototype, {
         }
 
         return super.setOrder(order);
+    },
+
+    async onDoRefund() {
+        const order = this.getSelectedOrder();
+        if (order && order.state === 'cancel') {
+            this.dialog.add(AlertDialog, {
+                title: _t("Refund Blocked"),
+                body: _t("You cannot refund a cancelled order."),
+            });
+            return;
+        }
+        return super.onDoRefund();
     }
 });