Remove quantity field from checkout (#7296)

* Remove checkoutline when variant/product was deleted

* cleanup

saleor/checkout/migrations/0034_remove_checkout_quantity.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.1.7 on 2021-04-28 07:01
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("checkout", "0033_checkout_language_code"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="checkout",
+            name="quantity",
+        ),
+    ]

saleor/checkout/models.py

@@ -47,7 +47,6 @@ class Checkout(ModelWithMetadata):
     )
     email = models.EmailField()
     token = models.UUIDField(primary_key=True, default=uuid4, editable=False)
-    quantity = models.PositiveIntegerField(default=0)
     channel = models.ForeignKey(
         Channel,
         related_name="checkouts",
@@ -98,9 +97,6 @@ class Meta(ModelWithMetadata.Meta):
             (CheckoutPermissions.MANAGE_CHECKOUTS.codename, "Manage checkouts"),
         )
 
-    def __repr__(self):
-        return "Checkout(quantity=%s)" % (self.quantity,)
-
     def __iter__(self):
         return iter(self.lines.all())
 

saleor/checkout/tests/test_cart.py

@@ -7,7 +7,7 @@
 from ...product.models import Category
 from .. import calculations, utils
 from ..models import Checkout
-from ..utils import add_variant_to_checkout
+from ..utils import add_variant_to_checkout, calculate_checkout_quantity
 
 
 @pytest.fixture()
@@ -35,11 +35,12 @@ def test_adding_same_variant(checkout, product):
     checkout_info = fetch_checkout_info(checkout, [], [], get_plugins_manager())
     add_variant_to_checkout(checkout_info, variant, 1)
     add_variant_to_checkout(checkout_info, variant, 2)
+    lines = fetch_checkout_lines(checkout)
+    checkout_quantity = calculate_checkout_quantity(lines)
     assert checkout.lines.count() == 1
-    assert checkout.quantity == 3
+    assert checkout_quantity == 3
     subtotal = TaxedMoney(Money("30.00", "USD"), Money("30.00", "USD"))
     manager = get_plugins_manager()
-    lines = fetch_checkout_lines(checkout)
     checkout_info = fetch_checkout_info(checkout, lines, [], manager)
     manager = get_plugins_manager()
     assert (
@@ -58,8 +59,9 @@ def test_replacing_same_variant(checkout, product):
     checkout_info = fetch_checkout_info(checkout, [], [], get_plugins_manager())
     add_variant_to_checkout(checkout_info, variant, 1, replace=True)
     add_variant_to_checkout(checkout_info, variant, 2, replace=True)
+    lines = fetch_checkout_lines(checkout)
     assert checkout.lines.count() == 1
-    assert checkout.quantity == 2
+    assert calculate_checkout_quantity(lines) == 2
 
 
 def test_adding_invalid_quantity(checkout, product):
@@ -243,14 +245,6 @@ def test_get_prices_of_discounted_specific_product_all_products(
     assert prices == excepted_value
 
 
-def test_checkout_repr():
-    checkout = Checkout()
-    assert repr(checkout) == "Checkout(quantity=0)"
-
-    checkout.quantity = 1
-    assert repr(checkout) == "Checkout(quantity=1)"
-
-
 def test_checkout_line_repr(product, checkout_with_single_item):
     variant = product.variants.get()
     line = checkout_with_single_item.lines.first()

saleor/checkout/tests/test_checkout.py

@@ -17,10 +17,16 @@
 from ...plugins.manager import get_plugins_manager
 from ...shipping.models import ShippingZone
 from .. import AddressType, calculations
-from ..fetch import CheckoutInfo, fetch_checkout_info, fetch_checkout_lines
+from ..fetch import (
+    CheckoutInfo,
+    CheckoutLineInfo,
+    fetch_checkout_info,
+    fetch_checkout_lines,
+)
 from ..models import Checkout
 from ..utils import (
     add_voucher_to_checkout,
+    calculate_checkout_quantity,
     cancel_active_payments,
     change_billing_address_in_checkout,
     change_shipping_address_in_checkout,
@@ -91,25 +97,25 @@ def test_last_change_update_foregin_key(checkout, shipping_method):
 
 
 @pytest.mark.parametrize(
-    "total, min_spent_amount, total_quantity, min_checkout_items_quantity, "
+    "total, min_spent_amount, min_checkout_items_quantity, "
     "discount_value, discount_value_type, expected_value",
     [
-        (20, 20, 2, 2, 50, DiscountValueType.PERCENTAGE, 10),
-        (20, None, 2, None, 50, DiscountValueType.PERCENTAGE, 10),
-        (20, 20, 2, 2, 5, DiscountValueType.FIXED, 5),
-        (20, None, 2, None, 5, DiscountValueType.FIXED, 5),
+        (20, 20, 2, 50, DiscountValueType.PERCENTAGE, 10),
+        (20, None, None, 50, DiscountValueType.PERCENTAGE, 10),
+        (20, 20, 2, 5, DiscountValueType.FIXED, 5),
+        (20, None, None, 5, DiscountValueType.FIXED, 5),
     ],
 )
 def test_get_discount_for_checkout_value_voucher(
     total,
     min_spent_amount,
-    total_quantity,
     min_checkout_items_quantity,
     discount_value,
     discount_value_type,
     expected_value,
     monkeypatch,
     channel_USD,
+    checkout_with_items,
 ):
     voucher = Voucher.objects.create(
         code="unique",
@@ -123,7 +129,7 @@ def test_get_discount_for_checkout_value_voucher(
         discount=Money(discount_value, channel_USD.currency_code),
         min_spent_amount=(min_spent_amount if min_spent_amount is not None else None),
     )
-    checkout = Mock(spec=Checkout, quantity=total_quantity, channel=channel_USD)
+    checkout = Mock(spec=checkout_with_items, channel=channel_USD)
     subtotal = TaxedMoney(Money(total, "USD"), Money(total, "USD"))
     monkeypatch.setattr(
         "saleor.checkout.utils.calculations.checkout_subtotal",
@@ -143,9 +149,20 @@ def test_get_discount_for_checkout_value_voucher(
         shipping_method_channel_listings=None,
         valid_shipping_methods=[],
     )
+    lines = [
+        CheckoutLineInfo(
+            line=line,
+            channel_listing=line.variant.product.channel_listings.first(),
+            collections=[],
+            product=line.variant.product,
+            variant=line.variant,
+            product_type=line.variant.product.product_type,
+        )
+        for line in checkout_with_items.lines.all()
+    ]
     manager = get_plugins_manager()
     discount = get_voucher_discount_for_checkout(
-        manager, voucher, checkout_info, [], None, []
+        manager, voucher, checkout_info, lines, None, []
     )
     assert discount == Money(expected_value, "USD")
 
@@ -156,12 +173,12 @@ def test_get_voucher_discount_for_checkout_voucher_validation(
 ):
     manager = get_plugins_manager()
     lines = fetch_checkout_lines(checkout_with_voucher)
+    quantity = calculate_checkout_quantity(lines)
     checkout_info = fetch_checkout_info(checkout_with_voucher, lines, [], manager)
     manager = get_plugins_manager()
     address = checkout_with_voucher.shipping_address
     get_voucher_discount_for_checkout(manager, voucher, checkout_info, lines, address)
     subtotal = manager.calculate_checkout_subtotal(checkout_info, lines, address, [])
-    quantity = checkout_with_voucher.quantity
     customer_email = checkout_with_voucher.get_customer_email()
     mock_validate_voucher.assert_called_once_with(
         voucher, subtotal.gross, quantity, customer_email, checkout_with_voucher.channel
@@ -201,7 +218,7 @@ def test_get_discount_for_checkout_entire_order_voucher_not_applicable(
         discount=Money(discount_value, channel_USD.currency_code),
         min_spent_amount=(min_spent_amount if min_spent_amount is not None else None),
     )
-    checkout = Mock(spec=Checkout, quantity=total_quantity, channel=channel_USD)
+    checkout = Mock(spec=Checkout, channel=channel_USD)
     subtotal = TaxedMoney(Money(total, "USD"), Money(total, "USD"))
     monkeypatch.setattr(
         "saleor.checkout.utils.calculations.checkout_subtotal",

saleor/checkout/utils.py

@@ -1,8 +1,10 @@
 """Checkout-related utility functions."""
 from typing import TYPE_CHECKING, Iterable, List, Optional, Tuple
 
+import graphene
 from django.core.exceptions import ValidationError
-from django.db.models import Sum
+from django.db.models import Count, F, OuterRef, Subquery, Sum
+from django.db.models.functions import Coalesce
 from django.utils import timezone
 from prices import Money
 
@@ -117,10 +119,13 @@ def add_variant_to_checkout(
         line.quantity = new_quantity
         line.save(update_fields=["quantity"])
 
-    checkout = update_checkout_quantity(checkout)
     return checkout
 
 
+def calculate_checkout_quantity(lines: Iterable["CheckoutLineInfo"]):
+    return sum([line_info.line.quantity for line_info in lines])
+
+
 def add_variants_to_checkout(checkout, variants, quantities, channel_slug):
     """Add variants to checkout.
 
@@ -151,19 +156,6 @@ def add_variants_to_checkout(checkout, variants, quantities, channel_slug):
             CheckoutLine(checkout=checkout, variant=variant, quantity=quantity)
         )
     checkout.lines.bulk_create(lines)
-    checkout = update_checkout_quantity(checkout)
-    return checkout
-
-
-def update_checkout_quantity(checkout):
-    """Update the total quantity in checkout."""
-    total_lines = checkout.lines.aggregate(total_quantity=Sum("quantity"))[
-        "total_quantity"
-    ]
-    if not total_lines:
-        total_lines = 0
-    checkout.quantity = total_lines
-    checkout.save(update_fields=["quantity"])
     return checkout
 
 
@@ -651,3 +643,28 @@ def is_shipping_required(lines: Iterable["CheckoutLineInfo"]):
     return any(
         line_info.product.product_type.is_shipping_required for line_info in lines
     )
+
+
+def validate_variants_in_checkout_lines(lines: Iterable["CheckoutLineInfo"]):
+    variants_listings_map = {line.variant.id: line.channel_listing for line in lines}
+
+    not_available_variants = [
+        variant_id
+        for variant_id, channel_listing in variants_listings_map.items()
+        if channel_listing is None or channel_listing.price is None
+    ]
+    if not_available_variants:
+        not_available_variants_ids = {
+            graphene.Node.to_global_id("ProductVariant", pk)
+            for pk in not_available_variants
+        }
+        error_code = CheckoutErrorCode.UNAVAILABLE_VARIANT_IN_CHANNEL
+        raise ValidationError(
+            {
+                "lines": ValidationError(
+                    "Cannot add lines with unavailable variants.",
+                    code=error_code,  # type: ignore
+                    params={"variants": not_available_variants_ids},
+                )
+            }
+        )

saleor/discount/utils.py

@@ -116,7 +116,9 @@ def validate_voucher_for_checkout(
     lines: Iterable["CheckoutLineInfo"],
     discounts: Optional[Iterable[DiscountInfo]],
 ):
-    checkout = checkout_info.checkout
+    from ..checkout.utils import calculate_checkout_quantity
+
+    quantity = calculate_checkout_quantity(lines)
     address = checkout_info.shipping_address or checkout_info.billing_address
     subtotal = calculations.checkout_subtotal(
         manager=manager,
@@ -130,7 +132,7 @@ def validate_voucher_for_checkout(
     validate_voucher(
         voucher,
         subtotal.gross,
-        checkout.quantity,
+        quantity,
         customer_email,
         checkout_info.channel,
     )

saleor/graphql/checkout/mutations.py

@@ -24,13 +24,14 @@
     add_promo_code_to_checkout,
     add_variant_to_checkout,
     add_variants_to_checkout,
+    calculate_checkout_quantity,
     change_billing_address_in_checkout,
     change_shipping_address_in_checkout,
     get_user_checkout,
     is_shipping_required,
     recalculate_checkout_discount,
     remove_promo_code_from_checkout,
-    update_checkout_quantity,
+    validate_variants_in_checkout_lines,
 )
 from ...core import analytics
 from ...core.exceptions import InsufficientStock, PermissionDenied, ProductNotPublished
@@ -92,8 +93,9 @@ def update_checkout_shipping_method_if_invalid(
     checkout_info: "CheckoutInfo", lines: Iterable[CheckoutLineInfo]
 ):
     checkout = checkout_info.checkout
+    quantity = calculate_checkout_quantity(lines)
     # remove shipping method when empty checkout
-    if checkout.quantity == 0 or not is_shipping_required(lines):
+    if quantity == 0 or not is_shipping_required(lines):
         checkout.shipping_method = None
         checkout_info.shipping_method = None
         checkout_info.shipping_method_channel_listings = None
@@ -538,7 +540,6 @@ def perform_mutation(cls, _root, info, checkout_id, line_id):
             checkout, lines, info.context.discounts, manager
         )
         update_checkout_shipping_method_if_invalid(checkout_info, lines)
-        update_checkout_quantity(checkout)
         recalculate_checkout_discount(
             manager, checkout_info, lines, info.context.discounts
         )
@@ -674,7 +675,6 @@ def perform_mutation(cls, _root, info, checkout_id, shipping_address):
 
         discounts = info.context.discounts
         manager = info.context.plugins
-        lines = fetch_checkout_lines(checkout)
         checkout_info = fetch_checkout_info(checkout, lines, discounts, manager)
 
         country = get_user_country_context(
@@ -936,12 +936,7 @@ def perform_mutation(cls, _root, info, checkout_id, store_source, **data):
 
             manager = info.context.plugins
             lines = fetch_checkout_lines(checkout)
-            variants_id = {line.variant.id for line in lines}
-            validate_variants_available_in_channel(
-                variants_id,
-                checkout.channel,
-                CheckoutErrorCode.UNAVAILABLE_VARIANT_IN_CHANNEL,
-            )
+            validate_variants_in_checkout_lines(lines)
             checkout_info = fetch_checkout_info(
                 checkout, lines, info.context.discounts, manager
             )