Fix outbox delete side effects

app/boxes.py

@@ -122,6 +122,19 @@ async def send_delete(db_session: AsyncSession, ap_object_id: str) -> None:
     for rcp in recipients:
         await new_outgoing_activity(db_session, rcp, outbox_object.id)
 
+    # Revert side effects
+    if outbox_object_to_delete.in_reply_to:
+        replied_object = await get_anybox_object_by_ap_id(
+            db_session, outbox_object_to_delete.in_reply_to
+        )
+        if replied_object:
+            replied_object.replies_count = replied_object.replies_count - 1
+            if replied_object.replies_count < 0:
+                logger.warning("negative replies count for {replied_object.ap_id}")
+                replied_object.replies_count = 0
+        else:
+            logger.info(f"{outbox_object_to_delete.in_reply_to} not found")
+
     await db_session.commit()
 
 

app/models.py

@@ -45,7 +45,7 @@ class Actor(Base, BaseActor):
     created_at = Column(DateTime(timezone=True), nullable=False, default=now)
     updated_at = Column(DateTime(timezone=True), nullable=False, default=now)
 
-    ap_id = Column(String, unique=True, nullable=False, index=True)
+    ap_id: Mapped[str] = Column(String, unique=True, nullable=False, index=True)
     ap_actor: Mapped[ap.RawObject] = Column(JSON, nullable=False)
     ap_type = Column(String, nullable=False)
 
@@ -126,7 +126,7 @@ class InboxObject(Base, BaseObject):
     is_deleted = Column(Boolean, nullable=False, default=False)
     is_transient = Column(Boolean, nullable=False, default=False, server_default="0")
 
-    replies_count = Column(Integer, nullable=False, default=0)
+    replies_count: Mapped[int] = Column(Integer, nullable=False, default=0)
 
     og_meta: Mapped[list[dict[str, Any]] | None] = Column(JSON, nullable=True)
 
@@ -176,7 +176,7 @@ class OutboxObject(Base, BaseObject):
 
     likes_count = Column(Integer, nullable=False, default=0)
     announces_count = Column(Integer, nullable=False, default=0)
-    replies_count = Column(Integer, nullable=False, default=0)
+    replies_count: Mapped[int] = Column(Integer, nullable=False, default=0)
     webmentions_count: Mapped[int] = Column(
         Integer, nullable=False, default=0, server_default="0"
     )

tests/factories.py

@@ -84,12 +84,13 @@ def build_move_activity(
 
 
 def build_note_object(
-    from_remote_actor: actor.RemoteActor,
+    from_remote_actor: actor.RemoteActor | models.Actor,
     outbox_public_id: str | None = None,
     content: str = "Hello",
     to: list[str] = None,
     cc: list[str] = None,
     tags: list[ap.RawObject] = None,
+    in_reply_to: str | None = None,
 ) -> ap.RawObject:
     published = now().replace(microsecond=0).isoformat().replace("+00:00", "Z")
     context = from_remote_actor.ap_id + "/ctx/" + uuid4().hex
@@ -108,8 +109,8 @@ def build_note_object(
         "url": from_remote_actor.ap_id + "/note/" + note_id,
         "tag": tags or [],
         "summary": None,
-        "inReplyTo": None,
         "sensitive": False,
+        "inReplyTo": in_reply_to,
     }
 
 

tests/test_outbox.py

@@ -2,13 +2,17 @@ from unittest import mock
 
 import respx
 from fastapi.testclient import TestClient
+from sqlalchemy import select
 from sqlalchemy.orm import Session
 
 from app import activitypub as ap
 from app import models
 from app import webfinger
+from app.actor import LOCAL_ACTOR
 from app.config import generate_csrf_token
 from tests.utils import generate_admin_session_cookies
+from tests.utils import setup_inbox_note
+from tests.utils import setup_outbox_note
 from tests.utils import setup_remote_actor
 from tests.utils import setup_remote_actor_as_follower
 
@@ -59,6 +63,63 @@ def test_send_follow_request(
     assert outgoing_activity.recipient == ra.inbox_url
 
 
+def test_send_delete__reverts_side_effects(
+    db: Session,
+    client: TestClient,
+    respx_mock: respx.MockRouter,
+) -> None:
+    # given a remote actor
+    ra = setup_remote_actor(respx_mock)
+
+    # who is a follower
+    follower = setup_remote_actor_as_follower(ra)
+    actor = follower.actor
+
+    # with a note that has existing replies
+    inbox_note = setup_inbox_note(actor)
+    inbox_note.replies_count = 1
+    db.commit()
+
+    # and a local reply
+    outbox_note = setup_outbox_note(
+        to=[ap.AS_PUBLIC],
+        cc=[LOCAL_ACTOR.followers_collection_id],  # type: ignore
+        in_reply_to=inbox_note.ap_id,
+    )
+    inbox_note.replies_count = inbox_note.replies_count + 1
+    db.commit()
+
+    response = client.post(
+        "/admin/actions/delete",
+        data={
+            "redirect_url": "http://testserver/",
+            "ap_object_id": outbox_note.ap_id,
+            "csrf_token": generate_csrf_token(),
+        },
+        cookies=generate_admin_session_cookies(),
+    )
+
+    # Then the server returns a 302
+    assert response.status_code == 302
+    assert response.headers.get("Location") == "http://testserver/"
+
+    # And the Delete activity was created in the outbox
+    outbox_object = db.execute(
+        select(models.OutboxObject).where(models.OutboxObject.ap_type == "Delete")
+    ).scalar_one()
+    assert outbox_object.ap_type == "Delete"
+    assert outbox_object.activity_object_ap_id == outbox_note.ap_id
+
+    # And an outgoing activity was queued
+    outgoing_activity = db.query(models.OutgoingActivity).one()
+    assert outgoing_activity.outbox_object_id == outbox_object.id
+    assert outgoing_activity.recipient == ra.inbox_url
+
+    # And the replies count of the replied object was decremented
+    db.refresh(inbox_note)
+    assert inbox_note.replies_count == 1
+
+
 def test_send_create_activity__no_followers_and_with_mention(
     db: Session,
     client: TestClient,

tests/utils.py

@@ -169,6 +169,53 @@ def setup_remote_actor_as_following_and_follower(
     return following, follower
 
 
+def setup_outbox_note(
+    content: str = "Hello",
+    to: list[str] = None,
+    cc: list[str] = None,
+    tags: list[ap.RawObject] = None,
+    in_reply_to: str | None = None,
+) -> models.OutboxObject:
+    note_id = uuid4().hex
+    note_from_outbox = RemoteObject(
+        factories.build_note_object(
+            from_remote_actor=LOCAL_ACTOR,
+            outbox_public_id=note_id,
+            content=content,
+            to=to,
+            cc=cc,
+            tags=tags,
+            in_reply_to=in_reply_to,
+        ),
+        LOCAL_ACTOR,
+    )
+    return factories.OutboxObjectFactory.from_remote_object(note_id, note_from_outbox)
+
+
+def setup_inbox_note(
+    actor: models.Actor,
+    content: str = "Hello",
+    to: list[str] = None,
+    cc: list[str] = None,
+    tags: list[ap.RawObject] = None,
+    in_reply_to: str | None = None,
+) -> models.OutboxObject:
+    note_id = uuid4().hex
+    note_from_outbox = RemoteObject(
+        factories.build_note_object(
+            from_remote_actor=actor,
+            outbox_public_id=note_id,
+            content=content,
+            to=to,
+            cc=cc,
+            tags=tags,
+            in_reply_to=in_reply_to,
+        ),
+        actor,
+    )
+    return factories.InboxObjectFactory.from_remote_object(note_from_outbox, actor)
+
+
 def setup_inbox_delete(
     actor: models.Actor, deleted_object_ap_id: str
 ) -> models.InboxObject: