Fix ValueError on Topic update by anonymous poster

https://itou.sentry.io/issues/4265102886/

lacommunaute/forum_conversation/forms.py

@@ -8,7 +8,18 @@
 from lacommunaute.notification.utils import should_not_be_approved
 
 
-class PostForm(AbstractPostForm):
+class UpdatePostMixin:
+    def update_post(self, post):
+        if self.user.is_anonymous:
+            post.username = self.cleaned_data["username"]
+            if should_not_be_approved(self.cleaned_data["username"]):
+                post.approved = False
+        else:
+            post.updated_by = self.user
+        post.updates_count = F("updates_count") + 1
+
+
+class PostForm(UpdatePostMixin, AbstractPostForm):
     subject = CharField(widget=HiddenInput(), required=False)
 
     def create_post(self):
@@ -21,17 +32,8 @@ def create_post(self):
 
         return post
 
-    def update_post(self, post):
-        if self.user.is_anonymous:
-            post.username = self.cleaned_data["username"]
-            if should_not_be_approved(self.cleaned_data["username"]):
-                post.approved = False
-        else:
-            post.updated_by = self.user
-        post.updates_count = F("updates_count") + 1
-
 
-class TopicForm(AbstractTopicForm):
+class TopicForm(UpdatePostMixin, AbstractTopicForm):
     tags = ModelMultipleChoiceField(
         label="", queryset=Tag.objects.all(), widget=CheckboxSelectMultiple, required=False
     )

lacommunaute/forum_conversation/tests/tests_views.py

@@ -18,7 +18,7 @@
 from lacommunaute.forum_conversation.enums import Filters
 from lacommunaute.forum_conversation.factories import CertifiedPostFactory, PostFactory, TopicFactory
 from lacommunaute.forum_conversation.forms import PostForm
-from lacommunaute.forum_conversation.models import Topic
+from lacommunaute.forum_conversation.models import Post, Topic
 from lacommunaute.forum_conversation.views import PostDeleteView, TopicCreateView
 from lacommunaute.forum_upvote.factories import UpVoteFactory
 from lacommunaute.notification.factories import BouncedEmailFactory
@@ -237,6 +237,44 @@ def test_selected_tags_are_checked(self):
         not_checked_box = f'class="form-check-input" type="checkbox" name="tags" value="{tag.id}" >'
         self.assertContains(response, not_checked_box)
 
+    def test_update_by_anonymous_user(self):
+        response = self.client.post(
+            reverse(
+                "forum_conversation:topic_create",
+                kwargs={
+                    "forum_slug": self.forum.slug,
+                    "forum_pk": self.forum.pk,
+                },
+            ),
+            {"subject": "subject", "content": "La communauté", "username": "[email protected]"},
+        )
+        post = Post.objects.select_related("topic").get(username="[email protected]")
+        topic = post.topic
+        response = self.client.post(
+            reverse(
+                "forum_conversation:topic_update",
+                kwargs={
+                    "forum_slug": self.forum.slug,
+                    "forum_pk": self.forum.pk,
+                    "slug": topic.slug,
+                    "pk": topic.pk,
+                },
+            ),
+            {"subject": "subject", "content": "La communauté", "username": "[email protected]"},
+        )
+        self.assertRedirects(
+            response,
+            reverse(
+                "forum_conversation:topic",
+                kwargs={
+                    "forum_slug": self.forum.slug,
+                    "forum_pk": self.forum.pk,
+                    "slug": topic.slug,
+                    "pk": topic.pk,
+                },
+            ),
+        )
+
 
 class PostCreateViewTest(TestCase):
     @classmethod