rake task to compute user null counter caches

Rakefile

@@ -622,3 +622,37 @@ desc "Enqueue pending post file jobs"
 task enqueue_pending_post_file_jobs: :environment do
   EnqueueDuePostFileJobs.new.run
 end
+
+desc "Compute null counter caches for all users"
+task compute_null_user_counter_caches: :environment do
+  counter_caches = {
+    user_post_creations_count: :user_post_creations,
+    user_post_favs_count: :user_post_favs,
+    user_user_follows_from_count: :user_user_follows_from,
+    user_user_follows_to_count: :user_user_follows_to,
+  }
+
+  query =
+    Domain::User.where(
+      counter_caches.map { |col, _| "(\"#{col}\" IS NULL)" }.join(" OR "),
+    )
+  total = query.count
+  query = query.select(:id, *counter_caches.keys)
+
+  puts "computing #{counter_caches.keys.join(", ")} for #{total} users"
+  pb = ProgressBar.create(total:, format: "%t: %c/%C %B %p%% %a %e")
+
+  query.find_in_batches(batch_size: 32) do |batch|
+    ReduxApplicationRecord.transaction do
+      batch.each do |user|
+        nil_caches =
+          counter_caches.keys.filter { |cache| user.send(cache).nil? }
+        Domain::User.reset_counters(
+          user.id,
+          *nil_caches.map { |col| counter_caches[col] },
+        )
+        pb.progress = [pb.progress + 1, total].min
+      end
+    end
+  end
+end