From 94e9c8f48a20e5cdd77854d40106acc7af10e16f Mon Sep 17 00:00:00 2001
From: Oneric <oneric@oneric.stub>
Date: Tue, 23 Apr 2024 23:59:42 +0200
Subject: [PATCH] Purge unused media description update on post
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In MastoAPI media descriptions are updated via the
media update API not upon post creation or post update.

This functionality was originally added about 6 years ago in
ba93396649f65a1f32eeedfd9ccd32cf308e7210 which was part of
https://git.pleroma.social/pleroma/pleroma/-/merge_requests/626 and
https://git.pleroma.social/pleroma/pleroma-fe/-/merge_requests/450.
They introduced image descriptions to the front- and backend,
but predate adoption of Mastodon API.

For a while adding an `descriptions` array on post creation might have
continued to work as an undocumented Pleroma extension to Masto API, but
at latest when OpenAPI specs were added for those endpoints four years
ago in 7803a85d2ced092fbd8e0f1bde0944bd27f8d649, these codepaths ceased
to be used. The API specs don’t list a `descriptions` parameter and
any unknown parameters are stripped out.

The attachments_from_ids function is only called from
ScheduledActivity and ActivityDraft.create with the latter
only being called by CommonAPI.{post,update} whihc in turn
are only called from ScheduledActivity again, MastoAPI controller
and without any attachment or description parameter WelcomeMessage.
Therefore no codepath can contain a descriptions parameter.
---
 lib/pleroma/web/common_api/utils.ex        | 25 ++++----------------
 test/pleroma/web/common_api/utils_test.exs | 27 ----------------------
 2 files changed, 4 insertions(+), 48 deletions(-)

diff --git a/lib/pleroma/web/common_api/utils.ex b/lib/pleroma/web/common_api/utils.ex
index e79b12fc9..d80109a98 100644
--- a/lib/pleroma/web/common_api/utils.ex
+++ b/lib/pleroma/web/common_api/utils.ex
@@ -22,19 +22,13 @@ defmodule Pleroma.Web.CommonAPI.Utils do
   require Logger
   require Pleroma.Constants
 
-  def attachments_from_ids(%{media_ids: ids, descriptions: desc}) do
-    attachments_from_ids_descs(ids, desc)
-  end
-
   def attachments_from_ids(%{media_ids: ids}) do
-    attachments_from_ids_no_descs(ids)
+    attachments_from_ids(ids)
   end
 
-  def attachments_from_ids(_), do: []
+  def attachments_from_ids([]), do: []
 
-  def attachments_from_ids_no_descs([]), do: []
-
-  def attachments_from_ids_no_descs(ids) do
+  def attachments_from_ids(ids) when is_list(ids) do
     Enum.map(ids, fn media_id ->
       case get_attachment(media_id) do
         %Object{data: data} -> data
@@ -44,18 +38,7 @@ def attachments_from_ids_no_descs(ids) do
     |> Enum.reject(&is_nil/1)
   end
 
-  def attachments_from_ids_descs([], _), do: []
-
-  def attachments_from_ids_descs(ids, descs_str) do
-    {_, descs} = Jason.decode(descs_str)
-
-    Enum.map(ids, fn media_id ->
-      with %Object{data: data} <- get_attachment(media_id) do
-        Map.put(data, "name", descs[media_id])
-      end
-    end)
-    |> Enum.reject(&is_nil/1)
-  end
+  def attachments_from_ids(_), do: []
 
   defp get_attachment(media_id) do
     Repo.get(Object, media_id)
diff --git a/test/pleroma/web/common_api/utils_test.exs b/test/pleroma/web/common_api/utils_test.exs
index f56d21c70..d98eb76ad 100644
--- a/test/pleroma/web/common_api/utils_test.exs
+++ b/test/pleroma/web/common_api/utils_test.exs
@@ -590,34 +590,7 @@ test "returns recipients when object not found" do
     end
   end
 
-  describe "attachments_from_ids_descs/2" do
-    test "returns [] when attachment ids is empty" do
-      assert Utils.attachments_from_ids_descs([], "{}") == []
-    end
-
-    test "returns list attachments with desc" do
-      object = insert(:note)
-      desc = Jason.encode!(%{object.id => "test-desc"})
-
-      assert Utils.attachments_from_ids_descs(["#{object.id}", "34"], desc) == [
-               Map.merge(object.data, %{"name" => "test-desc"})
-             ]
-    end
-  end
-
   describe "attachments_from_ids/1" do
-    test "returns attachments with descs" do
-      object = insert(:note)
-      desc = Jason.encode!(%{object.id => "test-desc"})
-
-      assert Utils.attachments_from_ids(%{
-               media_ids: ["#{object.id}"],
-               descriptions: desc
-             }) == [
-               Map.merge(object.data, %{"name" => "test-desc"})
-             ]
-    end
-
     test "returns attachments without descs" do
       object = insert(:note)
       assert Utils.attachments_from_ids(%{media_ids: ["#{object.id}"]}) == [object.data]