diff options
| -rw-r--r-- | rest_framework/validators.py | 7 | ||||
| -rw-r--r-- | tests/test_validators.py | 54 |
2 files changed, 60 insertions, 1 deletions
diff --git a/rest_framework/validators.py b/rest_framework/validators.py index e3719b8d..ab361614 100644 --- a/rest_framework/validators.py +++ b/rest_framework/validators.py @@ -138,7 +138,12 @@ class UniqueTogetherValidator: queryset = self.queryset queryset = self.filter_queryset(attrs, queryset) queryset = self.exclude_current_instance(attrs, queryset) - if queryset.exists(): + + # Ignore validation if any field is None + checked_values = [ + value for field, value in attrs.items() if field in self.fields + ] + if None not in checked_values and queryset.exists(): field_names = ', '.join(self.fields) raise ValidationError(self.message.format(field_names=field_names)) diff --git a/tests/test_validators.py b/tests/test_validators.py index 072cec36..127ec6f8 100644 --- a/tests/test_validators.py +++ b/tests/test_validators.py @@ -83,11 +83,37 @@ class UniquenessTogetherModel(models.Model): unique_together = ('race_name', 'position') +class NullUniquenessTogetherModel(models.Model): + """ + Used to ensure that null values are not included when checking + unique_together constraints. + + Ignoring items which have a null in any of the validated fields is the same + behavior that database backends will use when they have the + unique_together constraint added. + + Example case: a null position could indicate a non-finisher in the race, + there could be many non-finishers in a race, but all non-NULL + values *should* be unique against the given `race_name`. + """ + date_of_birth = models.DateField(null=True) # Not part of the uniqueness constraint + race_name = models.CharField(max_length=100) + position = models.IntegerField(null=True) + + class Meta: + unique_together = ('race_name', 'position') + + class UniquenessTogetherSerializer(serializers.ModelSerializer): class Meta: model = UniquenessTogetherModel +class NullUniquenessTogetherSerializer(serializers.ModelSerializer): + class Meta: + model = NullUniquenessTogetherModel + + class TestUniquenessTogetherValidation(TestCase): def setUp(self): self.instance = UniquenessTogetherModel.objects.create( @@ -182,6 +208,34 @@ class TestUniquenessTogetherValidation(TestCase): """) assert repr(serializer) == expected + def test_ignore_validation_for_null_fields(self): + # None values that are on fields which are part of the uniqueness + # constraint cause the instance to ignore uniqueness validation. + NullUniquenessTogetherModel.objects.create( + date_of_birth=datetime.date(2000, 1, 1), + race_name='Paris Marathon', + position=None + ) + data = { + 'date': datetime.date(2000, 1, 1), + 'race_name': 'Paris Marathon', + 'position': None + } + serializer = NullUniquenessTogetherSerializer(data=data) + assert serializer.is_valid() + + def test_do_not_ignore_validation_for_null_fields(self): + # None values that are not on fields part of the uniqueness constraint + # do not cause the instance to skip validation. + NullUniquenessTogetherModel.objects.create( + date_of_birth=datetime.date(2000, 1, 1), + race_name='Paris Marathon', + position=1 + ) + data = {'date': None, 'race_name': 'Paris Marathon', 'position': 1} + serializer = NullUniquenessTogetherSerializer(data=data) + assert not serializer.is_valid() + # Tests for `UniqueForDateValidator` # ---------------------------------- |