Order skus for increased cache hits.

LEARNER-4943

ecommerce/extensions/api/v2/tests/views/test_baskets.py

@@ -563,6 +563,9 @@ class BasketCalculateViewTests(ProgramTestMixin, TestCase):
         """Verify a request made with the is_anonymous parameter is cached"""
         url_with_one_sku = self._generate_sku_url(self.products, number_of_products=1, username=None)
         url_with_two_skus = self._generate_sku_url(self.products, number_of_products=2, username=None)
+        url_with_two_skus_reversed = self._generate_sku_url(
+            self.products, number_of_products=2, username=None, reverse_skus=True
+        )
 
         expected = {'Test Succeeded': True}
         mock_calculate_basket.return_value = expected
@@ -599,6 +602,14 @@ class BasketCalculateViewTests(ProgramTestMixin, TestCase):
         self.assertTrue(mock_calculate_basket.called, msg='The cache should be missed.')
         self.assertEqual(response.data, expected)
 
+        mock_calculate_basket.reset_mock()
+
+        # Check that this new set of skus hits cache, even when reversed
+        response = self.client.get(url_with_two_skus_reversed)
+        self.assertEqual(response.status_code, 200)
+        self.assertFalse(mock_calculate_basket.called, msg='The cache should be hit.')
+        self.assertEqual(response.data, expected)
+
         # Check that cache works and that log message is sent for Marketing user
         # Note: This and the following checks related to it should be removed once we remove
         # reliance on the Marketing user for caching.
@@ -782,7 +793,7 @@ class BasketCalculateViewTests(ProgramTestMixin, TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data, expected)
 
-    def _generate_sku_url(self, products, number_of_products=None, username=None):
+    def _generate_sku_url(self, products, number_of_products=None, username=None, reverse_skus=False):
         """
         Generates the calculate basket view's url for the given products
 
@@ -796,8 +807,11 @@ class BasketCalculateViewTests(ProgramTestMixin, TestCase):
         """
         if not number_of_products:
             number_of_products = len(products)
+        sku_list = [product.stockrecords.first().partner_sku for product in products[:number_of_products]]
+        if reverse_skus:
+            sku_list = list(reversed(sku_list))
         qs = urllib.urlencode(
-            {'sku': [product.stockrecords.first().partner_sku for product in products[:number_of_products]]},
+            {'sku': sku_list},
             True
         )
         url = '{root}?{qs}'.format(root=self.path, qs=qs)

ecommerce/extensions/api/v2/views/baskets.py

@@ -406,6 +406,7 @@ class BasketCalculateView(generics.GenericAPIView):
         skus = request.GET.getlist('sku')
         if not skus:
             return HttpResponseBadRequest(_('No SKUs provided.'))
+        skus.sort()
 
         code = request.GET.get('code', None)
         try: