Prevent delete serialized stock (#11872)

* Add setting to prevent deletion of serialized stock

Co-authored-by: Copilot <copilot@github.com>

* Add unit test

Co-authored-by: Copilot <copilot@github.com>

* Update CHANGELOG

Co-authored-by: Copilot <copilot@github.com>

---------

Co-authored-by: Copilot <copilot@github.com>

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- [#11872](https://github.com/inventree/InvenTree/pull/11872) adds a global setting to allow or disallow the deletion of serialized stock items.
 - [#11861](https://github.com/inventree/InvenTree/pull/11861) adds support for bulk-replacing a component in multiple BOMs simultaneously
 - [#11853](https://github.com/inventree/InvenTree/pull/11853) adds BOM comparison functionality, allowing users to compare the BOM of one assembly with another assembly.
 - [#11809](https://github.com/inventree/InvenTree/pull/11809) adds multi-level subassembly display mode to the BOM table, allowing users to view multiple levels of subassemblies in a single table view. This is an optional display mode which can be toggled on or off by the user.

docs/docs/settings/global.md

@@ -206,6 +206,7 @@ Configuration of stock item options
 | Name | Description | Default | Units |
 | ---- | ----------- | ------- | ----- |
 {{ globalsetting("SERIAL_NUMBER_GLOBALLY_UNIQUE") }}
+{{ globalsetting("STOCK_ALLOW_DELETE_SERIALIZED") }}
 {{ globalsetting("STOCK_DELETE_DEPLETED_DEFAULT") }}
 {{ globalsetting("STOCK_BATCH_CODE_TEMPLATE") }}
 {{ globalsetting("STOCK_ENABLE_EXPIRY") }}

src/backend/InvenTree/common/setting/system.py

@@ -716,6 +716,12 @@ SYSTEM_SETTINGS: dict[str, InvenTreeSettingsKeyType] = {
         'default': True,
         'validator': bool,
     },
+    'STOCK_ALLOW_DELETE_SERIALIZED': {
+        'name': _('Delete Serialized Stock'),
+        'description': _('Allow deletion of stock items which have a serial number'),
+        'default': True,
+        'validator': bool,
+    },
     'STOCK_BATCH_CODE_TEMPLATE': {
         'name': _('Batch Code Template'),
         'description': _('Template for generating default batch codes for stock items'),

src/backend/InvenTree/stock/models.py

@@ -449,6 +449,14 @@ class StockItem(
 
         order_insertion_by = ['part']
 
+    def delete(self, **kwargs):
+        """Custom delete method for StockItem model."""
+        if not get_global_setting('STOCK_ALLOW_DELETE_SERIALIZED', cache=False):
+            if self.serialized:
+                raise ValidationError(_('Serialized stock items cannot be deleted'))
+
+        super().delete(**kwargs)
+
     @staticmethod
     def get_api_url():
         """Return API url."""

src/backend/InvenTree/stock/test_api.py

@@ -2181,6 +2181,37 @@ class StockItemDeletionTest(StockAPITestCase):
 
         self.assertEqual(StockItem.objects.count(), n)
 
+    def test_delete_serialized(self):
+        """Test deletion of serialized stock items."""
+        trackable_part = part.models.Part.objects.create(
+            name='My part',
+            description='A trackable part',
+            trackable=True,
+            default_location=StockLocation.objects.get(pk=1),
+        )
+
+        stock_item = StockItem.objects.create(
+            part=trackable_part, quantity=1, serial='12345'
+        )
+
+        set_global_setting('STOCK_ALLOW_DELETE_SERIALIZED', False)
+
+        response = self.delete(
+            reverse('api-stock-detail', kwargs={'pk': stock_item.pk}), expected_code=400
+        )
+
+        self.assertIn('Serialized stock items cannot be deleted', str(response.data))
+
+        set_global_setting('STOCK_ALLOW_DELETE_SERIALIZED', True)
+
+        response = self.delete(
+            reverse('api-stock-detail', kwargs={'pk': stock_item.pk}), expected_code=204
+        )
+
+        self.get(
+            reverse('api-stock-detail', kwargs={'pk': stock_item.pk}), expected_code=404
+        )
+
 
 class StockTestResultTest(StockAPITestCase):
     """Tests for StockTestResult APIs."""

src/frontend/src/pages/Index/Settings/SystemSettings.tsx

@@ -245,6 +245,7 @@ export default function SystemSettings() {
             <GlobalSettingList
               keys={[
                 'SERIAL_NUMBER_GLOBALLY_UNIQUE',
+                'STOCK_ALLOW_DELETE_SERIALIZED',
                 'STOCK_DELETE_DEPLETED_DEFAULT',
                 'STOCK_BATCH_CODE_TEMPLATE',
                 'STOCK_OWNERSHIP_CONTROL',