Paperclip to ActiveStorage migration rake task

paperclip.rake

namespace :paperclip do
   task migrate: :environment do	
      arr = Array.new	
      ApplicationRecord.descendants.reject(&:abstract_class?).each { |klass| arr.push(klass) }	
      
      while model = arr.pop
         begin
            attachments = model.column_names.filter { |column| column.match?(/(.+)_file_name$/) }.map { |column| column[/(?<name>\w*)_file_name/, :name] }	
            next if attachments.blank?
            attachments.each do |attachment|
               query = <<~SQL
                  NOT EXISTS(
                     SELECT * FROM active_storage_blobs AS blobs
                     INNER JOIN active_storage_attachments AS attachments ON attachments.blob_id = blobs.id
                     WHERE record_type = ? AND record_id = #{model.table_name}.id
                  )
               SQL
               
               model.where.not("#{attachment}_file_name" => nil).where(query, model.name).find_each do |instance|
                  instance.instance_variable_set(:@is_migration, true)
                  instance.duplicate_active_storage if instance.respond_to?(:duplicate_active_storage)
               end
            end
         rescue OpenURI::HTTPError, ActiveRecord::StatementInvalid => e
            Rails.logger.error("Error during ActiveStorage migration: #{e} \n for #{model}")
            Raven.capture_exception("Error during ActiveStorage migration: #{e} \n for #{model}")
            next
         end
      end
   end
end