initial_count_for

# File activerecord/lib/active_record/associations/alias_tracker.rb, line 21
      def self.initial_count_for(connection, name, table_joins)
        quoted_name = nil

        counts = table_joins.map do |join|
          if join.is_a?(Arel::Nodes::StringJoin)
            # quoted_name should be case ignored as some database adapters (Oracle) return quoted name in uppercase
            quoted_name ||= connection.quote_table_name(name)

            # Table names + table aliases
            join.left.scan(
              /JOIN(?:\s+\w+)?\s+(?:\S+\s+)?(?:#{quoted_name}|#{name})\sON/
            ).size
          elsif join.is_a?(Arel::Nodes::Join)
            join.left.name == name ? 1 : 0
          elsif join.is_a?(Hash)
            join[name]
          else
            raise ArgumentError, "joins list should be initialized by list of Arel::Nodes::Join"
          end
        end

        counts.sum
      end