Merge pull request #1008 from edx/iivic/SOL-2111

[SOL-2111] Add Backend Validation for Coupon Creation - Benefit Type

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

@@ -273,6 +273,13 @@ class CouponViewSetFunctionalTest(CouponMixin, CourseCatalogTestMixin, CourseCat
         response_data = self.client.post(COUPONS_LINK, json.dumps(self.data), 'application/json')
         self.assertEqual(response_data.status_code, expected_status_code)
 
+    @ddt.data('', 'Incorrect benefit type')
+    def test_create_coupon_product_invalid_benefit_type(self, benefit_type):
+        """Test creating coupon when provided benefit type is invalid."""
+        self.data.update({'benefit_type': benefit_type})
+        response_data = self.client.post(COUPONS_LINK, json.dumps(self.data), 'application/json')
+        self.assertEqual(response_data.status_code, status.HTTP_400_BAD_REQUEST)
+
     def test_response(self):
         """Test the response data given after the order was created."""
         self.assertEqual(self.response.status_code, status.HTTP_200_OK)

ecommerce/extensions/offer/models.py

@@ -6,10 +6,28 @@ from django.conf import settings
 from django.core.cache import cache
 from django.core.exceptions import ValidationError
 from django.db import models
-from oscar.apps.offer.abstract_models import AbstractConditionalOffer, AbstractRange
+from django.utils.translation import ugettext_lazy as _
+from oscar.apps.offer.abstract_models import AbstractBenefit, AbstractConditionalOffer, AbstractRange
 from threadlocals.threadlocals import get_current_request
 
 
+VALID_BENEFIT_TYPES = [AbstractBenefit.PERCENTAGE, AbstractBenefit.FIXED]
+
+
+class Benefit(AbstractBenefit):
+    def save(self, *args, **kwargs):
+        self.clean()
+        super(Benefit, self).save(*args, **kwargs)  # pylint: disable=bad-super-call
+
+    def clean(self):
+        self.clean_type()
+        super(Benefit, self).clean()  # pylint: disable=bad-super-call
+
+    def clean_type(self):
+        if self.type not in VALID_BENEFIT_TYPES:
+            raise ValidationError(_('Unrecognised benefit type {type}'.format(type=self.type)))
+
+
 class ConditionalOffer(AbstractConditionalOffer):
     email_domains = models.CharField(max_length=255, blank=True, null=True)