fix for #6558 default value will not be passed through validated_data

docs/api-guide/validators.md

@@ -152,8 +152,6 @@ If you want the date field to be visible, but not editable by the user, then set
 
     published = serializers.DateTimeField(read_only=True, default=timezone.now)
 
-The field will not be writable to the user, but the default value will still be passed through to the `validated_data`.
-
 #### Using with a hidden date field.
 
 If you want the date field to be entirely hidden from the user, then use `HiddenField`. This field type does not accept user input, but instead always returns its default value to the `validated_data` in the serializer.

tests/test_validators.py

@@ -36,7 +36,8 @@ class RelatedModel(models.Model):
 
 class RelatedModelSerializer(serializers.ModelSerializer):
     username = serializers.CharField(source='user.username',
-        validators=[UniqueValidator(queryset=UniquenessModel.objects.all(), lookup='iexact')])  # NOQA
+                                     validators=[UniqueValidator(queryset=UniquenessModel.objects.all(),
+                                                                 lookup='iexact')])  # NOQA
 
     class Meta:
         model = RelatedModel
@@ -65,6 +66,14 @@ class UniquenessIntegerSerializer(serializers.Serializer):
     integer = serializers.CharField(validators=[UniqueValidator(queryset=IntegerFieldModel.objects.all())])
 
 
+class ReadonlyDefaultDateSerializer(serializers.Serializer):
+    """
+    This serializer is to test if read_only field
+    default value passed to validated data
+    """
+    published = serializers.DateField(read_only=True, default=datetime.date.today)
+
+
 class TestUniquenessValidation(TestCase):
     def setUp(self):
         self.instance = UniquenessModel.objects.create(username='existing')
@@ -245,10 +254,12 @@ def test_ignore_excluded_fields(self):
         When model fields are not included in a serializer, then uniqueness
         validators should not be added for that field.
         """
+
         class ExcludedFieldSerializer(serializers.ModelSerializer):
             class Meta:
                 model = UniquenessTogetherModel
                 fields = ('id', 'race_name',)
+
         serializer = ExcludedFieldSerializer()
         expected = dedent("""
             ExcludedFieldSerializer():
@@ -262,6 +273,7 @@ def test_ignore_read_only_fields(self):
         When serializer fields are read only, then uniqueness
         validators should not be added for that field.
         """
+
         class ReadOnlyFieldSerializer(serializers.ModelSerializer):
             class Meta:
                 model = UniquenessTogetherModel
@@ -281,6 +293,7 @@ def test_read_only_fields_with_default(self):
         """
         Special case of read_only + default DOES validate unique_together.
         """
+
         class ReadOnlyFieldWithDefaultSerializer(serializers.ModelSerializer):
             race_name = serializers.CharField(max_length=100, read_only=True, default='example')
 
@@ -305,6 +318,7 @@ def test_allow_explict_override(self):
         """
         Ensure validators can be explicitly removed..
         """
+
         class NoValidatorsSerializer(serializers.ModelSerializer):
             class Meta:
                 model = UniquenessTogetherModel
@@ -353,6 +367,7 @@ def test_filter_queryset_do_not_skip_existing_attribute(self):
         filter_queryset should add value from existing instance attribute
         if it is not provided in attributes dict
         """
+
         class MockQueryset:
             def filter(self, **kwargs):
                 self.called_with = kwargs
@@ -435,6 +450,7 @@ def test_updated_instance_excluded_from_unique_for_date(self):
             'published': datetime.date(2000, 1, 1)
         }
 
+
 # Tests for `UniqueForMonthValidator`
 # ----------------------------------
 
@@ -474,6 +490,7 @@ def test_unique_for_month(self):
             'published': datetime.date(2017, 2, 1)
         }
 
+
 # Tests for `UniqueForYearValidator`
 # ----------------------------------
 
@@ -555,24 +572,35 @@ class Meta:
         assert repr(serializer) == expected
 
 
+class TestReadOnlyDefaultValidation(TestCase):
+    # converting validated data to dict from ordered dict
+    def test_read_only_default_donot_exists_on_validated_data(self):
+        serializer = ReadonlyDefaultDateSerializer(data={})
+        self.assertTrue(serializer.is_valid())
+        self.assertDictEqual(dict(serializer.validated_data), {})
+
+
 class ValidatorsTests(TestCase):
 
     def test_qs_exists_handles_type_error(self):
         class TypeErrorQueryset:
             def exists(self):
                 raise TypeError
+
         assert qs_exists(TypeErrorQueryset()) is False
 
     def test_qs_exists_handles_value_error(self):
         class ValueErrorQueryset:
             def exists(self):
                 raise ValueError
+
         assert qs_exists(ValueErrorQueryset()) is False
 
     def test_qs_exists_handles_data_error(self):
         class DataErrorQueryset:
             def exists(self):
                 raise DataError
+
         assert qs_exists(DataErrorQueryset()) is False
 
     def test_validator_raises_error_if_not_all_fields_are_provided(self):