Merge pull request #54 from disconnect821/fix/mark-revision-relation-…

…as-protected

Fixed: mark revision relation as protected

wagtail_ab_testing/models.py

@@ -74,7 +74,7 @@ class AbTest(models.Model):
     page = models.ForeignKey('wagtailcore.Page', on_delete=models.CASCADE, related_name='ab_tests')
     name = models.CharField(max_length=255)
     hypothesis = models.TextField(blank=True)
-    variant_revision = models.ForeignKey('wagtailcore.Revision', on_delete=models.CASCADE, related_name='+')
+    variant_revision = models.ForeignKey('wagtailcore.Revision', on_delete=models.PROTECT, related_name='+')
     goal_event = models.CharField(max_length=255)
     goal_page = models.ForeignKey('wagtailcore.Page', null=True, blank=True, on_delete=models.SET_NULL, related_name='+')
     sample_size = models.PositiveIntegerField(validators=[MinValueValidator(1)])

wagtail_ab_testing/test/tests/test_abtest_model.py

@@ -2,7 +2,7 @@
 
 from django.test import TestCase
 from freezegun import freeze_time
-
+from django.db.models.deletion import ProtectedError
 from wagtail.models import Page
 
 from wagtail_ab_testing.models import AbTest, AbTestHourlyLog
@@ -165,6 +165,13 @@ def test_confidence_improves_with_more_participants(self):
 
         self.assertEqual(self.ab_test.check_for_winner(), AbTest.VERSION_CONTROL)
 
+    def test_check_raise_protect_error(self):
+        """
+        Test to check if ProtectedError is raised when associated revision is deleted
+        """
+        with self.assertRaises(ProtectedError):
+            self.ab_test.variant_revision.delete()
+
 
 class TestAutoCancelOnUnpublish(TestCase):
     def setUp(self):