Ruby pipeline

count_by_genre.rb

# Original

movies.group_by do |movie|
  movie.genre
end.map do |month, list|
  [month, list.size]
end.sort_by(&:last).reverse


# Alternative

movies
  .group_by { |movie| movie.genre }
  .map { |month, list| [month, list.size] }
  .sort_by(&:last)
  .reverse