diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py index a3d68b03db..56fa918dc8 100644 --- a/rest_framework/serializers.py +++ b/rest_framework/serializers.py @@ -609,6 +609,12 @@ def __init__(self, *args, **kwargs): self.min_length = kwargs.pop('min_length', None) assert self.child is not None, '`child` is a required argument.' assert not inspect.isclass(self.child), '`child` has not been instantiated.' + + instance = kwargs.get('instance', []) + data = kwargs.get('data', []) + if instance and data: + assert len(data) == len(instance), 'Data and instance should have same length' + super().__init__(*args, **kwargs) self.child.bind(field_name='', parent=self) @@ -683,7 +689,13 @@ def to_internal_value(self, data): ret = [] errors = [] - for item in data: + for idx, item in enumerate(data): + if ( + hasattr(self, 'instance') + and self.instance + and len(self.instance) > idx + ): + self.child.instance = self.instance[idx] try: validated = self.child.run_validation(item) except ValidationError as exc: diff --git a/tests/test_serializer.py b/tests/test_serializer.py index 10fa8afb94..39d9238ef9 100644 --- a/tests/test_serializer.py +++ b/tests/test_serializer.py @@ -2,6 +2,7 @@ import pickle import re import sys +import unittest from collections import ChainMap from collections.abc import Mapping @@ -783,3 +784,63 @@ def test_nested_key(self): ret = {'a': 1} self.s.set_value(ret, ['x', 'y'], 2) assert ret == {'a': 1, 'x': {'y': 2}} + + +class MyClass(models.Model): + name = models.CharField(max_length=100) + value = models.CharField(max_length=100, blank=True) + + app_label = "test" + + @property + def is_valid(self): + return self.name == 'valid' + + +class MyClassSerializer(serializers.ModelSerializer): + class Meta: + model = MyClass + fields = ('id', 'name', 'value') + + def validate_value(self, value): + if value and not self.instance.is_valid: + raise serializers.ValidationError( + 'Status cannot be set for invalid instance') + return value + + +class TestMultipleObjectsValidation(unittest.TestCase): + def setUp(self): + self.objs = [ + MyClass(name='valid'), + MyClass(name='invalid'), + MyClass(name='other'), + ] + + def test_multiple_objects_are_validated_separately(self): + + serializer = MyClassSerializer( + data=[{'value': 'set', 'id': instance.id} for instance in + self.objs], + instance=self.objs, + many=True, + partial=True, + ) + + assert not serializer.is_valid() + assert serializer.errors == [ + {}, + {'value': ['Status cannot be set for invalid instance']}, + {'value': ['Status cannot be set for invalid instance']} + ] + + def test_exception_raised_when_data_and_instance_length_different(self): + + with self.assertRaises(AssertionError): + MyClassSerializer( + data=[{'value': 'set', 'id': instance.id} for instance in + self.objs], + instance=self.objs[:-1], + many=True, + partial=True, + )