client_invoice.rb

module Invocing
  
  module Queries
    
    class FindClientInvoiceByOrder
      
      dependency :client_invoice_dao, ClientInvoice
      
      def call(order_id) 
        ClientInvoice.includes(:line_items).find_by(order_id: order_id)
      end
      
      def self.call(order)
        new.(order.id)
      end
      
    end
    
  end
  
end

usage.rb

client_invoice = Invoicing::Queries::FindClientInvoiceByOrder.(order)