Refactor the async user refreshing to use Oban

Previous implementation could cause duplicate simultaneous profile fetches which is not polite.

config/test.exs

@@ -183,8 +183,6 @@ config :pleroma, Pleroma.Emoji.Loader, test_emoji: true
 
 config :pleroma, Pleroma.Web.RichMedia.Backfill, provider: Pleroma.Web.RichMedia.Backfill
 
-config :pleroma, Pleroma.User, sync_refreshing: true
-
 if File.exists?("./config/test.secret.exs") do
   import_config "test.secret.exs"
 else

lib/pleroma/user.ex

@@ -38,6 +38,7 @@ defmodule Pleroma.User do
   alias Pleroma.Web.OAuth
   alias Pleroma.Web.RelMe
   alias Pleroma.Workers.BackgroundWorker
+  alias Pleroma.Workers.UserRefreshWorker
 
   require Logger
   require Pleroma.Constants
@@ -2165,12 +2166,9 @@ defmodule Pleroma.User do
   end
 
   defp maybe_refresh(user) do
-    fun = fn -> needs_update?(user) && fetch_by_ap_id(user.ap_id) end
-
-    if Config.get([__MODULE__, :sync_refreshing], false) do
-      fun.()
-    else
-      Task.start(fun)
+    if needs_update?(user) do
+      UserRefreshWorker.new(%{"ap_id" => user.ap_id})
+      |> Oban.insert()
     end
   end
 

lib/pleroma/workers/user_refresh_worker.ex

@@ -0,0 +1,14 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Workers.UserRefreshWorker do
+  use Pleroma.Workers.WorkerHelper, queue: "background", max_attempts: 1, unique: [period: 300]
+
+  alias Pleroma.User
+
+  @impl Oban.Worker
+  def perform(%Job{args: %{"ap_id" => ap_id}}) do
+    User.fetch_by_ap_id(ap_id)
+  end
+end

test/pleroma/user_test.exs

@@ -953,8 +953,12 @@ defmodule Pleroma.UserTest do
 
       {:ok, user} = User.get_or_fetch_by_ap_id("http://mastodon.example.org/users/admin")
 
-      # User was updated async, fetch from cache now
-      updated_user = User.get_cached_by_ap_id(user.ap_id)
+      # Oban job was generated to refresh the stale user
+      assert_enqueued(worker: "Pleroma.Workers.UserRefreshWorker", args: %{"ap_id" => user.ap_id})
+
+      # Run job to refresh the user; just capture its output instead of fetching it again
+      assert {:ok, updated_user} =
+               perform_job(Pleroma.Workers.UserRefreshWorker, %{"ap_id" => user.ap_id})
 
       assert updated_user.inbox