Merge pull request #900 from copitux/fix-validation-layer

Bugfix: Fix run validation layer with invalid data

rest_framework/serializers.py

@@ -315,7 +315,8 @@ class BaseSerializer(WritableField):
         self._errors = {}
         if data is not None or files is not None:
             attrs = self.restore_fields(data, files)
-            attrs = self.perform_validation(attrs)
+            if attrs is not None:
+                attrs = self.perform_validation(attrs)
         else:
             self._errors['non_field_errors'] = ['No input provided']
 

rest_framework/tests/test_validation.py

@@ -63,3 +63,25 @@ class TestPreSaveValidationExclusions(TestCase):
         # does not have `blank=True`, so this serializer should not validate.
         serializer = ShouldValidateModelSerializer(data={'renamed': ''})
         self.assertEqual(serializer.is_valid(), False)
+
+
+class ValidationSerializer(serializers.Serializer):
+    foo = serializers.CharField()
+
+    def validate_foo(self, attrs, source):
+        raise serializers.ValidationError("foo invalid")
+
+    def validate(self, attrs):
+        raise serializers.ValidationError("serializer invalid")
+
+
+class TestAvoidValidation(TestCase):
+    """
+    If serializer was initialized with invalid data (None or non dict-like), it
+    should avoid validation layer (validate_<field> and validate methods)
+    """
+    def test_serializer_errors_has_only_invalid_data_error(self):
+        serializer = ValidationSerializer(data='invalid data')
+        self.assertFalse(serializer.is_valid())
+        self.assertDictEqual(serializer.errors,
+                             {'non_field_errors': ['Invalid data']})