aggregate methods refactored using .send

rental_aggregate_refactored.rb

def self.count_vhs_rentals_by(attribute)
  Rental.all.each_with_object({}) do |rental, vhs_hash| 
    vhs_hash[rental.send(“#{attribute}”)].nil? ? vhs_hash[rental.“#{attribute}”] = 1 : vhs_hash[rental.“#{attribute}”] += 1 
  end
end

Vhs.count_vhs_rentals_by(“vhs”) #=>
#{<Vhs:0x00007f8d5e2bf0f0 id: 17, serial_number: "MAX-luqovgdk8e7tl", movie_id: 9 => 1,
 #<Vhs:0x00007f8d4f81a4a0 id: 29, serial_number: "BABA-t6k24krzqclts", movie_id: 13 =>2,
 #<Vhs:0x00007f8d4f854538 id: 11, serial_number: "BABA-begvxe7ai0rc6", movie_id: 13 =>3}

Vhs.count_vhs_rentals_by(“client”) #=>
#{#<Client:0x00007f8d5e2ae6d8 id: 4, name: "Hank Jennings" =>1}
 #<Client:0x00007f8d5e2be3a8 id: 7, name: "Lisa Wilkes" =>2}