feat: added tests for orders creation

shop/api/v1/viewsets.py

@@ -1,5 +1,9 @@
+from decimal import Decimal
+
 from django.db.models.deletion import ProtectedError
 from django.utils.text import gettext_lazy as _
+from django.shortcuts import get_object_or_404
+from django.db import transaction
 
 from rest_framework.viewsets import ModelViewSet
 from rest_framework.exceptions import ValidationError
@@ -101,5 +105,38 @@ class OrderLineViewSet(ModelViewSet):
     serializer_class = OrderLineSerializer
     queryset = OrderLine.objects.all()
 
+    def perform_create(self, serializer):
+        with transaction.atomic():
+            order = get_object_or_404(Order, uuid=self.kwargs.get('order_id'))
+            product = serializer.validated_data.get('product')
+            price = product.prices.last()
+            tax = price.tax.value
+            quantity = serializer.validated_data.get('quantity')
+            base_total = quantity * price.price
+            taxes = base_total * (tax / Decimal('100'))
+            total = base_total + taxes
+
+            instance = serializer.save(
+                order=order,
+                price=price.price,
+                base_total=base_total,
+                tax_value=tax,
+                taxes=taxes,
+                total=total,
+            )
+
+            order.base_total += instance.base_total
+            order.total += instance.total
+            order.save()
+
+    def perform_destroy(self, instance):
+        order = instance.order
+
+        with transaction.atomic():
+            order.base_total -= instance.base_total
+            order.total -= instance.total
+            instance.delete()
+            order.save()
+
     def get_queryset(self):
-        return super().get_queryset().filter(order_id=self.kwargs.get("order_id"))
+        return super().get_queryset().select_related('order').filter(order__uuid=self.kwargs.get("order_id"))