Add support for custom email validators on the registration page

new setting: EMAIL_VALIDATORS - tuple or list

tcms/kiwi_auth/forms.py

@@ -28,9 +28,14 @@ def validate_email_already_in_use(email):
         raise forms.ValidationError(_("A user with that email already exists."))
 
 
+def custom_email_validators(email):
+    for validator in getattr(settings, "EMAIL_VALIDATORS", ()):
+        validator(email)
+
+
 class RegistrationForm(UserCreationForm):  # pylint: disable=too-many-ancestors
     email = forms.EmailField(
-        validators=[validate_email_already_in_use],
+        validators=[validate_email_already_in_use, custom_email_validators],
     )
     captcha = (
         fields.CaptchaField(

tcms/kiwi_auth/tests/test_views.py

@@ -6,6 +6,7 @@
 from django.conf import settings
 from django.contrib.auth import get_user_model
 from django.contrib.sites.models import Site
+from django.forms import ValidationError
 from django.test import TestCase, override_settings
 from django.urls import reverse
 from django.utils import timezone
@@ -94,6 +95,11 @@ def test_logout_then_goto_next(self):
         self.assertRedirects(response, next_url)
 
 
+def deny_certain_email_addresses(email):
+    if email.lower().find("yahoo") > -1:
+        raise ValidationError("@yahoo email address has been denied")
+
+
 class TestRegistration(TestCase):
     def setUp(self):
         self.register_url = reverse("tcms-register")
@@ -285,6 +291,25 @@ def test_register_user_already_registered(self):
         user = User.objects.filter(username="test_user")
         self.assertEqual(user.count(), 0)
 
+    @override_settings(
+        EMAIL_VALIDATORS=(deny_certain_email_addresses,),
+    )
+    def test_custom_email_validators(self):
+        response = self.client.post(
+            self.register_url,
+            {
+                "username": "to_be_denied_user",
+                "password1": __FOR_TESTING__,
+                "password2": __FOR_TESTING__,
+                "email": "will-be-denied@yahoo.co.in",
+            },
+            follow=False,
+        )
+        self.assertContains(response, _("@yahoo email address has been denied"))
+
+        user = User.objects.filter(email__icontains="yahoo")
+        self.assertEqual(user.count(), 0)
+
     def test_first_user_is_superuser(self):
         _response, user = self.assert_user_registration("tester_1")
 

tcms/settings/common.py

@@ -67,6 +67,10 @@
 SERVER_EMAIL = DEFAULT_FROM_EMAIL = "kiwi@example.com"
 EMAIL_SUBJECT_PREFIX = "[Kiwi-TCMS] "
 
+# functions which can perform custom email address validation on the registration page
+# see tcms/kiwi_auth/tests/test_views.py::TestRegistration.test_custom_email_validators
+EMAIL_VALIDATORS = ()
+
 #  SMTP specific settings
 #  EMAIL_HOST = 'smtp.example.com'
 #  EMAIL_PORT = 25