WIP

Author: nabramow

…it_delete_to_discussions_and_comments.py …it_delete_to_discussions_and_comments.pyapp/backend/src/couchers/migrations/versions/0151_add_edit_delete_to_discussions_and_comments.py renamed to app/backend/src/couchers/migrations/versions/0155_add_edit_delete_to_discussions_and_comments.py app/backend/src/couchers/migrations/versions/0151_add_edit_delete_to_discussions_and_comments.py renamed to app/backend/src/couchers/migrations/versions/0155_add_edit_delete_to_discussions_and_comments.py

@@ -1,7 +1,7 @@
 """Add edit/delete support to discussions, comments, and replies
 
-Revision ID: 0151
-Revises: 0150
+Revision ID: 0155
+Revises: 0154
 Create Date: 2026-05-13 00:00:00.000000
 
 """
@@ -10,8 +10,8 @@
 from alembic import op
 
 # revision identifiers, used by Alembic.
-revision = "0151"
-down_revision = "0150"
+revision = "0155"
+down_revision = "0154"
 branch_labels = None
 depends_on = None
 

app/backend/src/couchers/servicers/admin.py

@@ -916,6 +916,8 @@ def DeleteDiscussion(
         ).scalar_one_or_none()
         if not discussion:
             context.abort_with_error_code(grpc.StatusCode.NOT_FOUND, "discussion_not_found")
+        if discussion.deleted is not None:
+            return empty_pb2.Empty()
         discussion.deleted = now()
         return empty_pb2.Empty()
 

app/backend/src/couchers/servicers/communities.py

@@ -4,7 +4,7 @@
 
 import grpc
 from google.protobuf import empty_pb2
-from sqlalchemy import exists, select
+from sqlalchemy import select
 from sqlalchemy.orm import Session, selectinload
 from sqlalchemy.sql import delete, func, or_
 
@@ -33,7 +33,7 @@
 from couchers.servicers.events import event_to_pb
 from couchers.servicers.groups import group_to_pb
 from couchers.servicers.pages import page_to_pb
-from couchers.sql import to_bool, users_visible, where_moderated_content_visible
+from couchers.sql import to_bool, users_visible, where_moderated_content_visible, where_users_column_visible
 from couchers.utils import Timestamp_from_datetime, dt_from_millis, millis_from_dt, now
 
 logger = logging.getLogger(__name__)
@@ -466,22 +466,46 @@ def ListDiscussions(
         self, request: communities_pb2.ListDiscussionsReq, context: CouchersContext, session: Session
     ) -> communities_pb2.ListDiscussionsRes:
         page_size = min(MAX_PAGINATION_LENGTH, request.page_size or MAX_PAGINATION_LENGTH)
-        next_page_id = int(request.page_token) if request.page_token else 0
+        next_page_id = int(request.page_token) if request.page_token else 2**63 - 1
         node = session.execute(select(Node).where(Node.id == request.community_id)).scalar_one_or_none()
         if not node:
             context.abort_with_error_code(grpc.StatusCode.NOT_FOUND, "community_not_found")
         if not node.official_cluster.small_community_features_enabled:
             context.abort_with_error_code(grpc.StatusCode.FAILED_PRECONDITION, "discussions_not_enabled")
-        has_comments = exists().where((Comment.thread_id == Discussion.thread_id) & (Comment.deleted == None))
-        query = (
-            node.official_cluster.owned_discussions.where((Discussion.deleted == None) | has_comments)
-            .where(or_(Discussion.id <= next_page_id, to_bool(next_page_id == 0)))
-            .order_by(Discussion.id.desc())
-            .limit(page_size + 1)
+        has_visible_comments = (
+            where_moderated_content_visible(
+                where_users_column_visible(
+                    select(func.count())
+                    .select_from(Comment)
+                    .where(Comment.thread_id == Discussion.thread_id)
+                    .where(Comment.deleted == None),
+                    context,
+                    Comment.author_user_id,
+                ),
+                context,
+                Comment,
+                is_list_operation=True,
+            )
+            .correlate(Discussion)
+            .scalar_subquery()
+        )
+        discussions = (
+            session.execute(
+                where_moderated_content_visible(
+                    select(Discussion)
+                    .where(Discussion.owner_cluster_id == node.official_cluster.id)
+                    .where((Discussion.deleted == None) | (has_visible_comments > 0))
+                    .where(Discussion.id <= next_page_id)
+                    .order_by(Discussion.id.desc())
+                    .limit(page_size + 1),
+                    context,
+                    Discussion,
+                    is_list_operation=True,
+                )
+            )
+            .scalars()
             .all()
         )
-        query = where_moderated_content_visible(query, context, Discussion, is_list_operation=True)
-        discussions = session.execute(query.order_by(Discussion.id.desc()).limit(page_size + 1)).scalars().all()
         return communities_pb2.ListDiscussionsRes(
             discussions=[discussion_to_pb(session, discussion, context) for discussion in discussions[:page_size]],
             next_page_token=str(discussions[-1].id) if len(discussions) > page_size else None,

app/backend/src/couchers/servicers/discussions.py

@@ -1,6 +1,7 @@
 import logging
 
 import grpc
+from google.protobuf import empty_pb2
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
@@ -18,7 +19,7 @@
 from couchers.servicers.blocking import is_not_visible
 from couchers.servicers.threads import thread_to_pb
 from couchers.sql import where_moderated_content_visible
-from couchers.utils import Timestamp_from_datetime
+from couchers.utils import Timestamp_from_datetime, now
 
 logger = logging.getLogger(__name__)
 
@@ -33,6 +34,17 @@ def discussion_to_pb(session: Session, discussion: Discussion, context: Couchers
     else:
         owner_group_id = discussion.owner_cluster.id
 
+    if discussion.deleted is not None:
+        return discussions_pb2.Discussion(
+            discussion_id=discussion.id,
+            slug=discussion.slug,
+            deleted=True,
+            owner_community_id=owner_community_id,
+            owner_group_id=owner_group_id,
+            owner_title=discussion.owner_cluster.name,
+            thread=thread_to_pb(session, context, discussion.thread_id),
+        )
+
     can_moderate = can_moderate_node(session, context.user_id, discussion.owner_cluster.parent_node_id)
 
     return discussions_pb2.Discussion(
@@ -47,6 +59,8 @@ def discussion_to_pb(session: Session, discussion: Discussion, context: Couchers
         content=discussion.content,
         thread=thread_to_pb(session, context, discussion.thread_id),
         can_moderate=can_moderate,
+        can_edit=(context.user_id == discussion.creator_user_id),
+        last_edited=Timestamp_from_datetime(discussion.last_edited) if discussion.last_edited else None,
     )
 
 
@@ -169,6 +183,78 @@ def GetDiscussion(
 
         return discussion_to_pb(session, discussion, context)
 
+    def UpdateDiscussion(
+        self, request: discussions_pb2.UpdateDiscussionReq, context: CouchersContext, session: Session
+    ) -> discussions_pb2.Discussion:
+        discussion = session.execute(
+            select(Discussion).where(Discussion.id == request.discussion_id)
+        ).scalar_one_or_none()
+        if not discussion:
+            context.abort_with_error_code(grpc.StatusCode.NOT_FOUND, "discussion_not_found")
+        if discussion.deleted is not None:
+            context.abort_with_error_code(grpc.StatusCode.FAILED_PRECONDITION, "discussion_deleted")
+        if context.user_id != discussion.creator_user_id:
+            context.abort_with_error_code(grpc.StatusCode.PERMISSION_DENIED, "discussion_edit_permission_denied")
+
+        updated = False
+
+        if request.HasField("title"):
+            new_title = request.title.value.strip()
+            if not new_title:
+                context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_discussion_title")
+            discussion.title = new_title
+            updated = True
+
+        if request.HasField("content"):
+            new_content = request.content.value.strip()
+            if not new_content:
+                context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_discussion_content")
+            discussion.content = new_content
+            updated = True
+
+        if not updated:
+            return discussion_to_pb(session, discussion, context)
+
+        discussion.last_edited = now()
+
+        log_event(
+            context,
+            session,
+            "discussion.updated",
+            {
+                "discussion_id": discussion.id,
+            },
+        )
+
+        return discussion_to_pb(session, discussion, context)
+
+    def DeleteDiscussion(
+        self, request: discussions_pb2.DeleteDiscussionReq, context: CouchersContext, session: Session
+    ) -> empty_pb2.Empty:
+        discussion = session.execute(
+            select(Discussion).where(Discussion.id == request.discussion_id)
+        ).scalar_one_or_none()
+        if not discussion:
+            context.abort_with_error_code(grpc.StatusCode.NOT_FOUND, "discussion_not_found")
+        if discussion.deleted is not None:
+            context.abort_with_error_code(grpc.StatusCode.FAILED_PRECONDITION, "discussion_deleted")
+
+        if context.user_id != discussion.creator_user_id:
+            context.abort_with_error_code(grpc.StatusCode.PERMISSION_DENIED, "discussion_delete_permission_denied")
+
+        discussion.deleted = now()
+
+        log_event(
+            context,
+            session,
+            "discussion.deleted",
+            {
+                "discussion_id": discussion.id,
+            },
+        )
+
+        return empty_pb2.Empty()
+
     def ListMyCommunitiesDiscussions(
         self, request: discussions_pb2.ListMyCommunitiesDiscussionsReq, context: CouchersContext, session: Session
     ) -> discussions_pb2.ListMyCommunitiesDiscussionsRes:

app/backend/src/couchers/servicers/threads.py

@@ -289,21 +289,30 @@ def GetThread(
                     is_list_operation=True,
                 )
             ).all()
-            replies = [
-                threads_pb2.Reply(
-                    thread_id=pack_thread_id(r.id, 1),
-                    deleted=r.deleted is not None,
-                    content=r.content if r.deleted is None else "",
-                    author_user_id=r.author_user_id if r.deleted is None else 0,
-                    created_time=Timestamp_from_datetime(r.created) if r.deleted is None else None,
-                    num_replies=n,
-                    can_edit=(context.user_id == r.author_user_id) if r.deleted is None else False,
-                    last_edited=Timestamp_from_datetime(r.last_edited)
-                    if (r.last_edited and r.deleted is None)
-                    else None,
-                )
-                for r, n in res[:page_size]
-            ]
+            # Deleted comments are shown as stubs (thread_id, deleted, num_replies only)
+            # to preserve thread structure, but content and author are stripped.
+            replies = []
+            for r, n in res[:page_size]:
+                if r.deleted is not None:
+                    replies.append(
+                        threads_pb2.Reply(
+                            thread_id=pack_thread_id(r.id, 1),
+                            deleted=True,
+                            num_replies=n,
+                        )
+                    )
+                else:
+                    replies.append(
+                        threads_pb2.Reply(
+                            thread_id=pack_thread_id(r.id, 1),
+                            content=r.content,
+                            author_user_id=r.author_user_id,
+                            created_time=Timestamp_from_datetime(r.created),
+                            num_replies=n,
+                            can_edit=(context.user_id == r.author_user_id),
+                            last_edited=Timestamp_from_datetime(r.last_edited) if r.last_edited else None,
+                        )
+                    )
 
         elif depth == 1:
             if not session.execute(

app/backend/src/tests/test_discussions.py

@@ -183,6 +183,13 @@ def test_update_discussion(db):
         assert res.title == "Updated title"
         assert res.content == "Updated content"
         assert res.can_edit
+        assert res.last_edited is not None
+
+    with discussions_session(token) as api:
+        res = api.GetDiscussion(discussions_pb2.GetDiscussionReq(discussion_id=discussion_id))
+        assert res.title == "Updated title"
+        assert res.content == "Updated content"
+        assert res.last_edited is not None
 
 
 def test_update_discussion_permission_denied(db):
@@ -263,18 +270,20 @@ def test_delete_discussion_by_creator(db):
         assert res.thread.thread_id != 0
 
 
-def test_delete_discussion_by_moderator(db):
+def test_delete_discussion_permission_denied_for_non_creator(db):
     creator, creator_token = generate_user()
-    moderator, moderator_token = generate_user()
+    community_admin, community_admin_token = generate_user()
     random_user, random_token = generate_user()
     with session_scope() as session:
-        community = create_community(session, 0, 1, "Testing Community", [moderator], [creator, random_user], None)
+        community = create_community(
+            session, 0, 1, "Testing Community", [community_admin], [creator, random_user], None
+        )
         community_id = community.id
 
     with discussions_session(creator_token) as api:
         res = api.CreateDiscussion(
             discussions_pb2.CreateDiscussionReq(
-                title="To be moderated",
+                title="Only creator can delete",
                 content="Some content",
                 owner_community_id=community_id,
             )
@@ -287,10 +296,10 @@ def test_delete_discussion_by_moderator(db):
             api.DeleteDiscussion(discussions_pb2.DeleteDiscussionReq(discussion_id=discussion_id))
         assert e.value.code() == grpc.StatusCode.PERMISSION_DENIED
 
-    with discussions_session(moderator_token) as api:
-        api.DeleteDiscussion(discussions_pb2.DeleteDiscussionReq(discussion_id=discussion_id))
-        res = api.GetDiscussion(discussions_pb2.GetDiscussionReq(discussion_id=discussion_id))
-        assert res.deleted
+    with discussions_session(community_admin_token) as api:
+        with pytest.raises(grpc.RpcError) as e:
+            api.DeleteDiscussion(discussions_pb2.DeleteDiscussionReq(discussion_id=discussion_id))
+        assert e.value.code() == grpc.StatusCode.PERMISSION_DENIED
 
 
 def test_deleted_discussion_not_in_list(db):
@@ -326,7 +335,7 @@ def test_deleted_discussion_not_in_list(db):
         assert deleted_id not in ids
 
 
-def test_deleted_discussion_thread_still_accessible(db):
+def test_deleted_discussion_thread_still_accessible(db, moderator: Moderator):
     user, token = generate_user()
     commenter, commenter_token = generate_user()
     with session_scope() as session:
@@ -347,7 +356,8 @@ def test_deleted_discussion_thread_still_accessible(db):
     process_jobs()
 
     with threads_session(commenter_token) as api:
-        api.PostReply(threads_pb2.PostReplyReq(thread_id=thread_id, content="a comment"))
+        comment_thread_id = api.PostReply(threads_pb2.PostReplyReq(thread_id=thread_id, content="a comment")).thread_id
+    moderator.approve_thread_post(comment_thread_id)
 
     with discussions_session(token) as api:
         api.DeleteDiscussion(discussions_pb2.DeleteDiscussionReq(discussion_id=discussion_id))
@@ -360,7 +370,7 @@ def test_deleted_discussion_thread_still_accessible(db):
         assert len(res.replies) == 1
 
 
-def test_delete_comment_shows_placeholder_with_replies(db):
+def test_delete_comment_shows_placeholder_with_replies(db, moderator: Moderator):
     """Deleting a top-level comment that has nested replies should show a deleted
     placeholder so the replies remain visible."""
     user, token = generate_user()
@@ -383,13 +393,22 @@ def test_delete_comment_shows_placeholder_with_replies(db):
 
     # commenter adds a top-level comment
     with threads_session(commenter_token) as api:
-        comment_res = api.PostReply(threads_pb2.PostReplyReq(thread_id=thread_id, content="top-level comment"))
-        comment_thread_id = comment_res.thread_id
+        comment_thread_id = api.PostReply(
+            threads_pb2.PostReplyReq(thread_id=thread_id, content="top-level comment")
+        ).thread_id
 
     # replier adds two nested replies
     with threads_session(replier_token) as api:
-        api.PostReply(threads_pb2.PostReplyReq(thread_id=comment_thread_id, content="nested reply 1"))
-        api.PostReply(threads_pb2.PostReplyReq(thread_id=comment_thread_id, content="nested reply 2"))
+        reply_thread_id_1 = api.PostReply(
+            threads_pb2.PostReplyReq(thread_id=comment_thread_id, content="nested reply 1")
+        ).thread_id
+        reply_thread_id_2 = api.PostReply(
+            threads_pb2.PostReplyReq(thread_id=comment_thread_id, content="nested reply 2")
+        ).thread_id
+
+    moderator.approve_thread_post(comment_thread_id)
+    moderator.approve_thread_post(reply_thread_id_1)
+    moderator.approve_thread_post(reply_thread_id_2)
 
     # commenter deletes their top-level comment
     with threads_session(commenter_token) as api: