fix(feeds): make sure posts for feeds are ordered by publication date desc

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon/posts/posts.ex

@@ -22,11 +22,13 @@ defmodule Mobilizon.Posts do
     :private
   ])
 
-  @spec list_public_local_posts(integer | nil, integer | nil) :: Page.t(Post.t())
-  def list_public_local_posts(page \\ nil, limit \\ nil) do
+  @spec list_public_local_posts(integer | nil, integer | nil, atom | nil, atom | nil) ::
+          Page.t(Post.t())
+  def list_public_local_posts(page \\ nil, limit \\ nil, sort \\ nil, direction \\ nil) do
     Post
     |> filter_public()
     |> filter_local()
+    |> order_posts(sort, direction)
     |> preload_post_associations()
     |> Page.build_page(page, limit)
   end
@@ -171,4 +173,13 @@ defmodule Mobilizon.Posts do
   defp preload_post_associations(query, associations \\ @post_preloads) do
     preload(query, ^associations)
   end
+
+  @spec order_posts(Ecto.Queryable.t(), atom | nil, atom | nil) :: Ecto.Queryable.t()
+  def order_posts(query, nil, _direction), do: query
+  def order_posts(query, _sort, nil), do: query
+
+  def order_posts(query, sort, direction) do
+    order_by_param = Keyword.new([{direction, sort}])
+    order_by(query, ^order_by_param)
+  end
 end

lib/service/export/common.ex

@@ -97,7 +97,7 @@ defmodule Mobilizon.Service.Export.Common do
   @spec fetch_instance_public_content(integer()) :: {:ok, list(Event.t()), list(Post.t())}
   def fetch_instance_public_content(limit) do
     %Page{elements: events} = Events.list_public_local_events(1, limit, :begins_on, :desc)
-    %Page{elements: posts} = Posts.list_public_local_posts(1, limit)
+    %Page{elements: posts} = Posts.list_public_local_posts(1, limit, :publish_at, :desc)
     {:ok, events, posts}
   end