From c4e43da63e03f66fd2feaa192c4d8192bbc3451c Mon Sep 17 00:00:00 2001
From: William Pitcock <nenolod@dereferenced.org>
Date: Thu, 1 Nov 2018 07:28:48 +0000
Subject: [PATCH 1/3] object: add safe object deletion function

---
 lib/pleroma/object.ex | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/pleroma/object.ex b/lib/pleroma/object.ex
index 1bcff5a7b..8f96fd8fb 100644
--- a/lib/pleroma/object.ex
+++ b/lib/pleroma/object.ex
@@ -1,6 +1,6 @@
 defmodule Pleroma.Object do
   use Ecto.Schema
-  alias Pleroma.{Repo, Object}
+  alias Pleroma.{Repo, Object, Activity}
   import Ecto.{Query, Changeset}
 
   schema "objects" do
@@ -52,4 +52,12 @@ def get_cached_by_ap_id(ap_id) do
   def context_mapping(context) do
     Object.change(%Object{}, %{data: %{"id" => context}})
   end
+
+  def delete(%Object{data: %{"id" => id}} = object) do
+    with Repo.delete(object),
+         Repo.delete_all(Activity.all_non_create_by_object_ap_id_q(id)),
+         {:ok, true} <- Cachex.del(:user_cache, "object:#{id}") do
+      :ok
+    end
+  end
 end

From 2bf358d7b47f3c2dda91b0ac638b6a068fb40a4c Mon Sep 17 00:00:00 2001
From: William Pitcock <nenolod@dereferenced.org>
Date: Thu, 1 Nov 2018 07:29:12 +0000
Subject: [PATCH 2/3] activitypub: use Object.delete() instead of mutating the
 database and cache directly

---
 lib/pleroma/web/activity_pub/activity_pub.ex | 3 +--
 lib/pleroma/web/common_api/common_api.ex     | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 5a81f6fa2..48ae36ebd 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -273,8 +273,7 @@ def delete(%Object{data: %{"id" => id, "actor" => actor}} = object, local \\ tru
       "to" => [user.follower_address, "https://www.w3.org/ns/activitystreams#Public"]
     }
 
-    with Repo.delete(object),
-         Repo.delete_all(Activity.all_non_create_by_object_ap_id_q(id)),
+    with Object.delete(object),
          {:ok, activity} <- insert(data, local),
          :ok <- maybe_federate(activity),
          {:ok, _actor} <- User.decrease_note_count(user) do
diff --git a/lib/pleroma/web/common_api/common_api.ex b/lib/pleroma/web/common_api/common_api.ex
index 8607cb6b3..8f47bb127 100644
--- a/lib/pleroma/web/common_api/common_api.ex
+++ b/lib/pleroma/web/common_api/common_api.ex
@@ -9,8 +9,7 @@ def delete(activity_id, user) do
     with %Activity{data: %{"object" => %{"id" => object_id}}} <- Repo.get(Activity, activity_id),
          %Object{} = object <- Object.normalize(object_id),
          true <- user.info["is_moderator"] || user.ap_id == object.data["actor"],
-         {:ok, delete} <- ActivityPub.delete(object),
-         {:ok, true} <- Cachex.del(:user_cache, "object:#{object_id}") do
+         {:ok, delete} <- ActivityPub.delete(object) do
       {:ok, delete}
     end
   end

From f55fc68f766c71e81ce754408007e3b763f32e0f Mon Sep 17 00:00:00 2001
From: William Pitcock <nenolod@dereferenced.org>
Date: Thu, 1 Nov 2018 07:37:07 +0000
Subject: [PATCH 3/3] tests: add tests for object deletion

---
 test/object_test.exs | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/test/object_test.exs b/test/object_test.exs
index 5eb9b7530..3e398776c 100644
--- a/test/object_test.exs
+++ b/test/object_test.exs
@@ -19,4 +19,34 @@ test "it ensures uniqueness of the id" do
       {:error, _result} = Repo.insert(cs)
     end
   end
+
+  describe "deletion function" do
+    test "deletes an object" do
+      object = insert(:note)
+      found_object = Object.get_by_ap_id(object.data["id"])
+
+      assert object == found_object
+
+      Object.delete(found_object)
+
+      found_object = Object.get_by_ap_id(object.data["id"])
+
+      refute object == found_object
+    end
+
+    test "ensures cache is cleared for the object" do
+      object = insert(:note)
+      cached_object = Object.get_cached_by_ap_id(object.data["id"])
+
+      assert object == cached_object
+
+      Object.delete(cached_object)
+
+      {:ok, nil} = Cachex.get(:user_cache, "object:#{object.data["id"]}")
+
+      cached_object = Object.get_cached_by_ap_id(object.data["id"])
+
+      refute object == cached_object
+    end
+  end
 end