Order conversation fetches like GS does.

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -77,7 +77,8 @@ def unfollow(follower, followed, local \\ true) do
 
   def fetch_activities_for_context(context) do
     query = from activity in Activity,
-      where: fragment("? @> ?", activity.data, ^%{ context: context })
+      where: fragment("? @> ?", activity.data, ^%{ context: context }),
+      order_by: [desc: :inserted_at]
     Repo.all(query)
   end
 

test/web/activity_pub/activity_pub_test.exs

@@ -75,7 +75,7 @@ test "retrieves activities that have a given context" do
 
       activities = ActivityPub.fetch_activities_for_context("2hu")
 
-      assert activities == [activity, activity_two]
+      assert activities == [activity_two, activity]
     end
   end
 

test/web/twitter_api/twitter_api_test.exs

@@ -227,8 +227,8 @@ test "fetch statuses in a context using the conversation id" do
     statuses = TwitterAPI.fetch_conversation(user, object.id)
 
     assert length(statuses) == 2
-    assert Enum.at(statuses, 0)["id"] == activity.id
-    assert Enum.at(statuses, 1)["id"] == activity_two.id
+    assert Enum.at(statuses, 1)["id"] == activity.id
+    assert Enum.at(statuses, 0)["id"] == activity_two.id
   end
 
   test "upload a file" do