Create tombstone instead of object deletion

test/activity_test.exs

@@ -1,5 +1,6 @@
 defmodule Pleroma.ActivityTest do
   use Pleroma.DataCase
+  alias Pleroma.Activity
   import Pleroma.Factory
 
   test "returns an activity by it's AP id" do
@@ -24,4 +25,28 @@ defmodule Pleroma.ActivityTest do
 
     assert activity == found_activity
   end
+
+  test "returns tombstone" do
+    activity = insert(:note_activity)
+    deleted = DateTime.utc_now()
+
+    assert Pleroma.Activity.get_tombstone(activity, deleted) == %{
+             id: activity.data["object"]["id"],
+             context: activity.data["context"],
+             type: "tombstone",
+             published: activity.data["published"],
+             deleted: deleted
+           }
+  end
+
+  test "swaps data with tombstone" do
+    activity = insert(:note_activity)
+
+    {:ok, deleted} = Pleroma.Activity.swap_data_with_tombstone(activity)
+    assert deleted.data.type == "tombstone"
+
+    found_activity = Repo.get(Activity, activity.id)
+
+    assert deleted.data.type == found_activity.data["type"]
+  end
 end