feat: statement for supplier and customer

stock/tests.py

@@ -328,35 +328,128 @@ class MakeStockChangeCompletedTestCase(StockServicesTestCase):
             product_id=self.product_fabric_a.id,
             warehouse_id=self.warehouse_main.id
         )
-    
+
     def test_complete_inbound_record_existing_inventory(self):
         """测试完成入库记录（更新现有库存）"""
-        # 创建现有库存
         existing_inventory = models.Inventory.objects.create(
             merchant=self.merchant,
             product=self.product_fabric_a,
             warehouse=self.warehouse_main,
             quantity=50,
-            num_of_rolls=5
+            num_of_rolls=5,
         )
-        
+
         with patch('stock.services.create_stock_snapshot') as mock_snapshot:
             mock_snapshot.return_value = MagicMock()
-            
             result = services.make_stock_change_completed(self.stock_change_in)
-        
+
         self.assertTrue(result)
-        
-        # 检查库存更新
         existing_inventory.refresh_from_db()
-        self.assertEqual(existing_inventory.quantity, 150)  # 50 + 100
-        self.assertEqual(existing_inventory.num_of_rolls, 6)  # 5 + 1
-        
-        # 验证记录状态
+        self.assertEqual(existing_inventory.quantity, 150)
+        self.assertEqual(existing_inventory.num_of_rolls, 6)
+
         self.stock_change_in.refresh_from_db()
         self.assertTrue(self.stock_change_in.is_finished)
 
 
+class StockOffsetServiceTestCase(TestCase):
+    """测试库存红冲逻辑"""
+
+    def setUp(self):
+        self.merchant = Merchant.objects.create(
+            name='红冲商户',
+            type=MerchantTypeEnum.STORE,
+        )
+        self.warehouse = WareHouse.objects.create(
+            merchant=self.merchant,
+            name='红冲仓',
+            mode=WareHouseModeEnum.RESTRICT_IN,
+        )
+        category = ProductCategory.objects.create(
+            merchant=self.merchant,
+            name='红冲品类',
+            product_prefix='RC',
+        )
+        self.product = Product.objects.create(
+            merchant=self.merchant,
+            category=category,
+            name='红冲产品',
+            human_id='RC-001',
+            unit=ProductUnitEnum.METER,
+        )
+        self.stock_service = services.StockFlowService(merchant=self.merchant, created_by=None)
+
+        self.source_record, _, _ = services.create_stock_change_record_with_details(
+            merchant=self.merchant,
+            created_by=None,
+            type=models.StockChangeTypeEnum.ADD,
+            warehouse_id=self.warehouse.id,
+            source_type=models.StockChangeSourceEnum.PURCHASE,
+            source_id=101,
+            products=[{'product': self.product.id, 'quantity': [Decimal('10')]}],
+        )
+        services.make_stock_change_completed(self.source_record)
+
+    def test_offset_stock_change_creates_reverse_record(self):
+        offset_record, details, detail_count = self.stock_service.offset_stock_change(
+            source_record_id=self.source_record.id,
+            reason='测试红冲',
+        )
+        self.assertEqual(offset_record.type, models.StockChangeTypeEnum.REMOVE)
+        self.assertEqual(offset_record.source_type, models.StockChangeSourceEnum.OFFSET)
+        self.assertEqual(detail_count, 1)
+        self.assertEqual(len(details), 1)
+
+        inventory = models.Inventory.objects.get(product=self.product, warehouse=self.warehouse)
+        self.assertEqual(inventory.quantity, 0)
+
+        self.assertTrue(
+            models.StockSnapshot.objects.filter(
+                stock_change_record=self.source_record,
+                cancelled=True,
+                offset_id__isnull=False,
+            ).exists()
+        )
+
+    def test_offset_cannot_repeat(self):
+        self.stock_service.offset_stock_change(
+            source_record_id=self.source_record.id,
+            reason='第一次红冲',
+        )
+        with self.assertRaises(ValueError):
+            self.stock_service.offset_stock_change(
+                source_record_id=self.source_record.id,
+                reason='再次红冲',
+            )
+
+    def test_offset_requires_finished_record(self):
+        record, _, _ = services.create_stock_change_record_with_details(
+            merchant=self.merchant,
+            created_by=None,
+            type=models.StockChangeTypeEnum.ADD,
+            warehouse_id=self.warehouse.id,
+            source_type=models.StockChangeSourceEnum.PURCHASE,
+            source_id=202,
+            products=[{'product': self.product.id, 'quantity': [Decimal('8')]}],
+        )
+        with self.assertRaises(ValueError):
+            self.stock_service.offset_stock_change(
+                source_record_id=record.id,
+                reason='未完成记录红冲',
+            )
+
+    def test_offset_checks_merchant(self):
+        other_merchant = Merchant.objects.create(
+            name='外部商户',
+            type=MerchantTypeEnum.STORE,
+        )
+        other_service = services.StockFlowService(merchant=other_merchant, created_by=None)
+        with self.assertRaises(ValueError):
+            other_service.offset_stock_change(
+                source_record_id=self.source_record.id,
+                reason='跨商户红冲',
+            )
+    
 class CreateStockChangeRecordWithDetailsTestCase(StockServicesTestCase):
     """测试 create_stock_change_record_with_details 服务"""
 
@@ -893,8 +986,8 @@ class StockFlowServiceTestCase(TestCase):
             source_id=11,
             items=[{'product_id': self.product.id, 'value': '9', 'num_of_rolls': 4}],
         )
-        self.assertEqual(count, 3)  # 4 + 4 + 1
-        self.assertEqual(len(details), 3)
+        self.assertEqual(count, 4)
+        self.assertEqual(len(details), 4)
 
     def test_stock_out_restrict_mode_consumes_details(self):
         _, inbound_details, _ = self.service.stock_in(