From 4f559b6df24ac5d92c1d6ea3498892d29463611e Mon Sep 17 00:00:00 2001
From: Prateek Karamchandani
 <40106895+prateekkaramchandani@users.noreply.github.com>
Date: Wed, 5 Mar 2025 16:37:42 +0530
Subject: [PATCH] fix: allow variant uom to differ from template uom (#45850)

---
 erpnext/stock/doctype/item/item.py            | 16 +++++---
 erpnext/stock/doctype/item/test_item.py       | 39 +++++++++++++++++++
 .../item_variant_settings.json                |  9 ++++-
 .../item_variant_settings.py                  |  1 +
 4 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/erpnext/stock/doctype/item/item.py b/erpnext/stock/doctype/item/item.py
index ee3aba14404..c800a93c66d 100644
--- a/erpnext/stock/doctype/item/item.py
+++ b/erpnext/stock/doctype/item/item.py
@@ -896,13 +896,17 @@ class Item(Document):
 			for d in frappe.db.get_all("Item", filters={"variant_of": self.name}):
 				check_stock_uom_with_bin(d.name, self.stock_uom)
 		if self.variant_of:
-			template_uom = frappe.db.get_value("Item", self.variant_of, "stock_uom")
-			if template_uom != self.stock_uom:
-				frappe.throw(
-					_("Default Unit of Measure for Variant '{0}' must be same as in Template '{1}'").format(
-						self.stock_uom, template_uom
+			allow_different_uom = frappe.get_cached_value(
+				"Item Variant Settings", "Item Variant Settings", "allow_different_uom"
+			)
+			if not allow_different_uom:
+				template_uom = frappe.db.get_value("Item", self.variant_of, "stock_uom")
+				if template_uom != self.stock_uom:
+					frappe.throw(
+						_(
+							"Default Unit of Measure for Variant '{0}' must be same as in Template '{1}'"
+						).format(self.stock_uom, template_uom)
 					)
-				)
 
 	def validate_uom_conversion_factor(self):
 		if self.uoms:
diff --git a/erpnext/stock/doctype/item/test_item.py b/erpnext/stock/doctype/item/test_item.py
index e17a8c8eada..d13456c249e 100644
--- a/erpnext/stock/doctype/item/test_item.py
+++ b/erpnext/stock/doctype/item/test_item.py
@@ -933,6 +933,45 @@ class TestItem(IntegrationTestCase):
 
 		self.assertRaises(frappe.ValidationError, item_doc.save)
 
+	def test_variant_uom_mismatch_throws_error(self):
+		frappe.db.set_single_value("Item Variant Settings", "allow_different_uom", 0)
+
+		template_item = frappe.get_doc(
+			{
+				"doctype": "Item",
+				"item_code": "_Test Template UOM",
+				"item_name": "_Test Template UOM",
+				"item_group": "_Test Item Group",
+				"stock_uom": "Kg",
+				"is_stock_item": 1,
+				"has_variants": 1,
+				"attributes": [
+					{"attribute": "Test Size"},
+				],
+			}
+		).insert()
+
+		with self.assertRaises(frappe.ValidationError) as ve:
+			frappe.get_doc(
+				{
+					"doctype": "Item",
+					"item_code": "_Test Variant UOM",
+					"item_name": "_Test Variant UOM",
+					"item_group": "_Test Item Group",
+					"stock_uom": "Litre",
+					"is_stock_item": 1,
+					"variant_of": template_item.name,
+					"attributes": [
+						{"attribute": "Test Size", "attribute_value": "Small"},
+					],
+				}
+			).insert()
+
+		self.assertTrue(
+			"must be same as in Template" in str(ve.exception),
+			msg="Different Variant UOM should not be allowed when `allow_different_uom` is disabled.",
+		)
+
 
 def set_item_variant_settings(fields):
 	doc = frappe.get_doc("Item Variant Settings")
diff --git a/erpnext/stock/doctype/item_variant_settings/item_variant_settings.json b/erpnext/stock/doctype/item_variant_settings/item_variant_settings.json
index 8aea8a46778..7d7a2b9fc3d 100644
--- a/erpnext/stock/doctype/item_variant_settings/item_variant_settings.json
+++ b/erpnext/stock/doctype/item_variant_settings/item_variant_settings.json
@@ -8,6 +8,7 @@
   "section_break_3",
   "do_not_update_variants",
   "allow_rename_attribute_value",
+  "allow_different_uom",
   "copy_fields_to_variant",
   "fields"
  ],
@@ -40,11 +41,17 @@
    "fieldtype": "Table",
    "label": "Fields",
    "options": "Variant Field"
+  },
+  {
+   "default": "0",
+   "fieldname": "allow_different_uom",
+   "fieldtype": "Check",
+   "label": "Allow Variant UOM to be different from Template UOM"
   }
  ],
  "issingle": 1,
  "links": [],
- "modified": "2024-03-27 13:09:56.095684",
+ "modified": "2025-02-10 16:13:47.435148",
  "modified_by": "Administrator",
  "module": "Stock",
  "name": "Item Variant Settings",
diff --git a/erpnext/stock/doctype/item_variant_settings/item_variant_settings.py b/erpnext/stock/doctype/item_variant_settings/item_variant_settings.py
index 277042c9d6f..dbaf35fbf4e 100644
--- a/erpnext/stock/doctype/item_variant_settings/item_variant_settings.py
+++ b/erpnext/stock/doctype/item_variant_settings/item_variant_settings.py
@@ -18,6 +18,7 @@ class ItemVariantSettings(Document):
 
 		from erpnext.stock.doctype.variant_field.variant_field import VariantField
 
+		allow_different_uom: DF.Check
 		allow_rename_attribute_value: DF.Check
 		do_not_update_variants: DF.Check
 		fields: DF.Table[VariantField]