Add custom validation to password change serializer (#359)

Co-authored-by: Thomas Gamauf <thomas.gamauf@gkcs.eu>

dj_rest_auth/serializers.py

@@ -345,11 +345,15 @@ def validate_old_password(self, value):
             raise serializers.ValidationError(err_msg)
         return value
 
+    def custom_validation(self, attrs):
+        pass
+
     def validate(self, attrs):
         self.set_password_form = self.set_password_form_class(
             user=self.user, data=attrs,
         )
 
+        self.custom_validation(attrs)
         if not self.set_password_form.is_valid():
             raise serializers.ValidationError(self.set_password_form.errors)
         return attrs

dj_rest_auth/tests/test_serializers.py

@@ -1,9 +1,12 @@
 from django.contrib.auth import get_user_model
+from django.urls import reverse
 from django.core.exceptions import ValidationError
 from django.test import TestCase, modify_settings, override_settings
 from rest_framework.exceptions import ErrorDetail
+from rest_framework.test import APIRequestFactory, force_authenticate
+from unittest.mock import MagicMock
 
-from dj_rest_auth.serializers import UserDetailsSerializer
+from dj_rest_auth.serializers import PasswordChangeSerializer, UserDetailsSerializer
 
 
 User = get_user_model()
@@ -57,3 +60,42 @@ def test_validate_username_without_all_auth(self):
         )
         self.assertEqual(True, serializer.is_valid())
         self.assertEqual(serializer.validated_data, {'username': 'TestUsername'})
+
+
+class TestPasswordChangeSerializer(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        user = User.objects.create_user(
+            username='alice', email='alice@test.com', first_name='Alice',
+        )
+        request_data = {
+            'new_password1': 'Password',
+            'new_password2': 'Password'
+        }
+        request = APIRequestFactory().post(request_data, format='json')
+        force_authenticate(request, user)
+
+        cls.request_data = request_data
+        cls.request = request
+
+    def test_custom_validation(self):
+        # Test custom validation success
+        PasswordChangeSerializer.custom_validation = MagicMock(return_value=True)
+        serializer = PasswordChangeSerializer(
+            reverse("rest_password_change"),
+            data=self.request_data
+        )
+        serializer.validate(self.request_data)
+        PasswordChangeSerializer.custom_validation.assert_called_once_with(self.request_data)
+
+        # Test custom validation error
+        PasswordChangeSerializer.custom_validation = MagicMock(
+            side_effect=ValidationError("failed")
+        )
+        serializer = PasswordChangeSerializer(
+            reverse("rest_password_change"),
+            data=self.request_data
+        )
+        with self.assertRaisesMessage(ValidationError, "failed"):
+            serializer.validate(self.request_data)
+