Use Django's standard uniqueness error formatter and add field key

This improves things in the following ways:
- The exception object contains a key to indicate which field is causing the problem.
- The exception object contains a "code"/slug which can be used to programmatically deal with the error.  Very useful in JSON APIs.
- We now use a standard text message that is more in line with the rest of Django (which also means it is translatable)

partial_index/mixins.py

@@ -1,4 +1,4 @@
-from django.core.exceptions import ImproperlyConfigured, ValidationError
+from django.core.exceptions import ImproperlyConfigured, ValidationError, NON_FIELD_ERRORS
 from django.db.models import Q
 
 from .index import PartialIndex
@@ -92,7 +92,8 @@ def validate_partial_unique(self):
  conflict = conflict.exclude(pk=self.pk) # Step 4
 
  if conflict.exists():
- raise PartialUniqueValidationError('%s with the same values for %s already exists.' % (
- self.__class__.__name__,
- ', '.join(sorted(idx.fields)),
- ))
+ if len(idx.fields) == 1:
+ key = idx.fields[0]
+ else:
+ key = NON_FIELD_ERRORS
+ raise PartialUniqueValidationError({key: self.unique_error_message(self.__class__, sorted(idx.fields))})

tests/test_forms.py

@@ -21,7 +21,7 @@ class FormTestCase(object):
  """Base class for form tests.
  """
  formclass = None
- conflict_error = 'RoomBookingQ with the same values for room, user already exists.'
+ conflict_error = 'Room booking q with this Room and User already exists.'
 
  def setUp(self):
  self.user1 = User.objects.create(name='User1')
@@ -98,7 +98,7 @@ class SingleFieldFormTest(FormTestCase, TransactionTestCase):
 class NullableFieldFormTest(TransactionTestCase):
  """Test that partial unique validation on a ModelForm treats null values as non-unique."""
  formclass = NullableRoomNumberAllFieldsForm
- conflict_error = 'NullableRoomNumberQ with the same values for room, room_number already exists.'
+ conflict_error = 'Nullable room number q with this Room and Room number already exists.'
 
  def setUp(self):
  self.room1 = Room.objects.create(name='Room1')

tests/test_models.py

@@ -4,6 +4,7 @@
 from django.db import IntegrityError
 from django.test import TransactionTestCase
 from django.utils import timezone
+from django.core.exceptions import NON_FIELD_ERRORS, ValidationError
 
 from testapp.models import User, Room, RoomBookingText, JobText, ComparisonText, NullableRoomNumberText, RoomBookingQ, JobQ, ComparisonQ, NullableRoomNumberQ
 
@@ -57,8 +58,16 @@ def test_roombooking_text_same_conflict(self):
 
  def test_roombooking_q_same_conflict(self):
  RoomBookingQ.objects.create(user=self.user1, room=self.room1)
+
+ room_booking = RoomBookingQ(user=self.user1, room=self.room1)
+ with self.assertRaises(ValidationError) as cm:
+ room_booking.full_clean()
+
+ self.assertSetEqual({NON_FIELD_ERRORS}, set(cm.exception.message_dict.keys()))
+ self.assertEqual('unique_together', cm.exception.error_dict[NON_FIELD_ERRORS][0].code)
+
  with self.assertRaises(IntegrityError):
- RoomBookingQ.objects.create(user=self.user1, room=self.room1)
+ room_booking.save()
 
 
 class PartialIndexJobTest(TransactionTestCase):
@@ -83,8 +92,16 @@ def test_job_text_same_group(self):
 
  def test_job_q_same_group(self):
  JobQ.objects.create(order=1, group=1)
+
+ job = JobQ(order=2, group=1)
+ with self.assertRaises(ValidationError) as cm:
+ job.full_clean()
+
+ self.assertSetEqual({'group'}, set(cm.exception.message_dict.keys()))
+ self.assertEqual('unique', cm.exception.error_dict['group'][0].code)
+
  with self.assertRaises(IntegrityError):
- JobQ.objects.create(order=2, group=1)
+ job.save()
 
  def test_job_text_complete_same_group(self):
  job1 = JobText.objects.create(order=1, group=1, is_complete=True)

tests/testapp/models.py

@@ -65,7 +65,7 @@ class Meta:
  ]
 
 
-class JobQ(models.Model):
+class JobQ(ValidatePartialUniqueMixin, models.Model):
  order = models.IntegerField()
  group = models.IntegerField()
  is_complete = models.BooleanField(default=False)