From 868034375c5122175f872967e49559dafed9403c Mon Sep 17 00:00:00 2001
From: sxsdv1 <sxsdv1@gmail.com>
Date: Wed, 9 Jan 2019 09:22:00 +0100
Subject: [PATCH] Add likes to activitypub object representation

Top level of the likes OrderedCollection is inlined to get immediate
access to totalItems. Because the count can be returned without scanning
the database for like activities the extra query is saved when the
client only wants to display the total.
---
 lib/pleroma/web/activity_pub/transmogrifier.ex | 18 +++++++++++++++++-
 test/web/activity_pub/transmogrifier_test.exs  | 10 ++++++++--
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index b0f8c59cc..86d11c874 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -629,6 +629,7 @@ def prepare_object(object) do
     |> add_mention_tags
     |> add_emoji_tags
     |> add_attributed_to
+    |> add_likes
     |> prepare_attachments
     |> set_conversation
     |> set_reply_to_uri
@@ -788,6 +789,22 @@ def add_attributed_to(object) do
     |> Map.put("attributedTo", attributedTo)
   end
 
+  def add_likes(%{"id" => id, "like_count" => likes} = object) do
+    likes = %{
+      "id" => "#{id}/likes",
+      "first" => "#{id}/likes?page=1",
+      "type" => "OrderedCollection",
+      "totalItems" => likes
+    }
+
+    object
+    |> Map.put("likes", likes)
+  end
+
+  def add_likes(object) do
+    object
+  end
+
   def prepare_attachments(object) do
     attachments =
       (object["attachment"] || [])
@@ -803,7 +820,6 @@ def prepare_attachments(object) do
   defp strip_internal_fields(object) do
     object
     |> Map.drop([
-      "likes",
       "like_count",
       "announcements",
       "announcement_count",
diff --git a/test/web/activity_pub/transmogrifier_test.exs b/test/web/activity_pub/transmogrifier_test.exs
index 65c8ec36d..87d0ab559 100644
--- a/test/web/activity_pub/transmogrifier_test.exs
+++ b/test/web/activity_pub/transmogrifier_test.exs
@@ -829,7 +829,6 @@ test "it strips internal fields" do
       assert length(modified["object"]["tag"]) == 2
 
       assert is_nil(modified["object"]["emoji"])
-      assert is_nil(modified["object"]["likes"])
       assert is_nil(modified["object"]["like_count"])
       assert is_nil(modified["object"]["announcements"])
       assert is_nil(modified["object"]["announcement_count"])
@@ -844,12 +843,19 @@ test "it strips internal fields of article" do
       assert length(modified["object"]["tag"]) == 2
 
       assert is_nil(modified["object"]["emoji"])
-      assert is_nil(modified["object"]["likes"])
       assert is_nil(modified["object"]["like_count"])
       assert is_nil(modified["object"]["announcements"])
       assert is_nil(modified["object"]["announcement_count"])
       assert is_nil(modified["object"]["context_id"])
     end
+
+    test "it adds like collection to object" do
+      activity = insert(:note_activity)
+      {:ok, modified} = Transmogrifier.prepare_outgoing(activity.data)
+
+      assert modified["object"]["likes"]["type"] == "OrderedCollection"
+      assert modified["object"]["likes"]["totalItems"] == 0
+    end
   end
 
   describe "user upgrade" do