Fix the api serializer so history data, if missing, are returned correctly

ecommerce/extensions/api/serializers.py

@@ -7,6 +7,7 @@ from decimal import Decimal
 import waffle
 from dateutil.parser import parse
 from django.contrib.auth import get_user_model
+from django.core.exceptions import ObjectDoesNotExist
 from django.db import transaction
 from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
@@ -298,7 +299,10 @@ class CourseSerializer(serializers.HyperlinkedModelSerializer):
             self.fields.pop('products', None)
 
     def get_last_edited(self, obj):
-        return obj.history.latest().history_date.strftime(ISO_8601_FORMAT)
+        try:
+            return obj.history.latest().history_date.strftime(ISO_8601_FORMAT)
+        except ObjectDoesNotExist:
+            return None
 
     def get_products_url(self, obj):
         return reverse('api:v2:course-product-list', kwargs={'parent_lookup_course_id': obj.id},
@@ -634,8 +638,11 @@ class CouponSerializer(ProductPaymentInfoMixin, serializers.ModelSerializer):
         return offer_range.enterprise_customer if offer_range else None
 
     def get_last_edited(self, obj):
-        history = obj.history.latest()
-        return history.history_user.username, history.history_date
+        try:
+            history = obj.history.latest()
+            return history.history_user.username, history.history_date
+        except ObjectDoesNotExist:
+            return None
 
     def get_max_uses(self, obj):
         offer = retrieve_offer(obj)

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

@@ -490,6 +490,13 @@ class CouponViewSetFunctionalTest(CouponMixin, DiscoveryTestMixin, DiscoveryMock
         self.assertEqual(coupon_data['category']['name'], self.data['category']['name'])
         self.assertEqual(coupon_data['client'], self.data['client'])
 
+    def test_list_coupons_no_history(self):
+        self.coupon.history.all().delete()
+        response = self.client.get(COUPONS_LINK)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        coupon_data = json.loads(response.content)['results'][0]
+        self.assertEqual(coupon_data.get('last_edited'), None)
+
     def test_list_and_details_endpoint_return_custom_code(self):
         """Test that the list and details endpoints return the correct code."""
         self.data.update({
@@ -516,6 +523,11 @@ class CouponViewSetFunctionalTest(CouponMixin, DiscoveryTestMixin, DiscoveryMock
         self.client.post(COUPONS_LINK, json.dumps(self.data), 'application/json')
         self.assert_post_response_status(self.data)
 
+    def test_coupon_details_no_history(self):
+        self.coupon.history.all().delete()
+        detail_response = self.get_response_json('GET', reverse('api:v2:coupons-detail', args=[self.coupon.id]))
+        self.assertEqual(detail_response['last_edited'], None)
+
     def test_update(self):
         """Test updating a coupon."""
         response_data = self.get_response_json(

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

@@ -6,6 +6,7 @@ import jwt
 import mock
 from django.conf import settings
 from django.contrib.auth import get_user_model
+from django.core.exceptions import ObjectDoesNotExist
 from django.core.urlresolvers import reverse
 from oscar.core.loading import get_class, get_model
 
@@ -41,7 +42,11 @@ class CourseViewSetTests(ProductSerializerMixin, DiscoveryTestMixin, TestCase):
         products_url = self.get_full_url(reverse('api:v2:course-product-list',
                                                  kwargs={'parent_lookup_course_id': course.id}))
 
-        last_edited = course.history.latest().history_date.strftime(ISO_8601_FORMAT)
+        last_edited = None
+        try:
+            last_edited = course.history.latest().history_date.strftime(ISO_8601_FORMAT)
+        except ObjectDoesNotExist:
+            pass
         enrollment_code = course.enrollment_code_product
 
         data = {
@@ -109,6 +114,14 @@ class CourseViewSetTests(ProductSerializerMixin, DiscoveryTestMixin, TestCase):
         response = self.client.get(self.list_path)
         self.assertDictEqual(json.loads(response.content), {'count': 0, 'next': None, 'previous': None, 'results': []})
 
+    def test_list_without_history(self):
+        course = Course.objects.all()[0]
+        course.history.all().delete()
+
+        response = self.client.get(self.list_path)
+        self.assertEqual(response.status_code, 200)
+        self.assertListEqual(json.loads(response.content)['results'], [self.serialize_course(self.course)])
+
     def test_create(self):
         """ Verify the view can create a new Course."""
         Course.objects.all().delete()

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

@@ -39,7 +39,7 @@ class StockRecordViewSetTests(ProductSerializerMixin, DiscoveryTestMixin, Thrott
         self.assertEqual(StockRecord.objects.count(), 4)
 
         results = [self.serialize_stockrecord(stockrecord) for stockrecord in
-                   self.product.stockrecords.all()]
+                   self.product.stockrecords.all().order_by('id')]
         expected = {'count': 2, 'next': None, 'previous': None, 'results': results}
         self.assertDictEqual(json.loads(response.content), expected)
 

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

@@ -13,7 +13,7 @@ class StockRecordViewSet(viewsets.ModelViewSet):
     serializer_class = serializers.StockRecordSerializer
 
     def get_queryset(self):
-        return StockRecord.objects.filter(partner=self.request.site.siteconfiguration.partner)
+        return StockRecord.objects.filter(partner=self.request.site.siteconfiguration.partner).order_by('id')
 
     def get_serializer_class(self):
         serializer_class = self.serializer_class

ecommerce/extensions/voucher/tests/test_utils.py

@@ -419,6 +419,22 @@ class UtilTests(CouponMixin, DiscoveryMockMixin, DiscoveryTestMixin, LmsApiMockM
         self.assertNotIn('Course Seat Types', field_names)
         self.assertNotIn('Redeemed For Course ID', field_names)
 
+    def test_report_with_no_coupon_history(self):
+        self.setup_coupons_for_report()
+        self.coupon.history.all().delete()
+        client = UserFactory()
+        basket = Basket.get_basket(client, self.site)
+        basket.add_product(self.coupon)
+
+        vouchers = self.coupon_vouchers.first().vouchers.all()
+        self.use_voucher('TESTORDER1', vouchers[1], self.user)
+
+        self.mock_course_api_response(course=self.course)
+        _, rows = generate_coupon_report(self.coupon_vouchers)
+        first_row = rows.pop(0)
+        self.assertEqual(first_row.get('Created By'), 'N/A')
+        self.assertEqual(first_row.get('Create Date'), 'N/A')
+
     def test_report_for_dynamic_coupon_with_fixed_benefit_type(self):
         """ Verify the coupon report contains correct data for coupon with fixed benefit type. """
         dynamic_coupon = self.create_coupon(

ecommerce/extensions/voucher/utils.py

@@ -94,8 +94,12 @@ def _get_discount_info(discount_data):
 
 
 def _get_info_for_coupon_report(coupon, voucher):
+    author = 'N/A'
+    created_date = 'N/A'
     history = coupon.history.first()
-    author = history.history_user.full_name
+    if history:
+        author = history.history_user.full_name
+        created_date = history.history_date.strftime("%b %d, %y")
     category_name = ProductCategory.objects.get(product=coupon).category.name
 
     try:
@@ -146,7 +150,7 @@ def _get_info_for_coupon_report(coupon, voucher):
         'Coupon Start Date': voucher.start_datetime.strftime("%b %d, %y"),
         'Coupon Type': coupon_type,
         'Created By': author,
-        'Create Date': history.history_date.strftime("%b %d, %y"),
+        'Create Date': created_date,
         'Discount Percentage': discount_percentage,
         'Discount Amount': discount_amount,
         'Email Domains': offer.email_domains,