✨ [#2303] Always inject toestemming when subscribing to newsletter

src/open_inwoner/laposta/client.py

@@ -43,7 +43,7 @@ def get_lists(self) -> list[LapostaList]:
 
     def create_subscription(self, list_id: str, user_data: UserData) -> Member | None:
         response = self.post(
-            "member", data={"list_id": list_id, **user_data.model_dump()}
+            "member", json={"list_id": list_id, **user_data.model_dump()}
         )
 
         if response.status_code == 400:

src/open_inwoner/laposta/forms.py

@@ -68,7 +68,7 @@ def save(self, request, *args, **kwargs):
             ip=get_client_ip(request)[0],
             email=user.verified_email,
             source_url=None,
-            custom_fields=None,
+            custom_fields={"toestemming": "Ja, ik wil de nieuwsbrief ontvangen"},
             options=None,
         )
         limited_to = LapostaConfig.get_solo().limit_list_selection_to

src/open_inwoner/laposta/tests/test_forms.py

@@ -1,5 +1,4 @@
 from unittest.mock import patch
-from urllib.parse import parse_qs
 
 from django.test import RequestFactory, TestCase, tag
 from django.utils.translation import gettext as _
@@ -128,8 +127,15 @@ def test_save_form(self, m):
         [post_request] = post_matcher.request_history
 
         self.assertEqual(
-            parse_qs(post_request.body),
-            {"list_id": ["789"], "ip": ["127.0.0.1"], "email": [self.user.email]},
+            post_request.json(),
+            {
+                "list_id": "789",
+                "ip": "127.0.0.1",
+                "email": self.user.email,
+                "custom_fields": {"toestemming": "Ja, ik wil de nieuwsbrief ontvangen"},
+                "source_url": None,
+                "options": None,
+            },
         )
 
         # Because list_id 123 was present in the