gitlabhq/app/roles/votes.rb

# == Votes role
#
# Provides functionality to upvote/downvote entity
# based on +1 and -1 notes
#
# Used for Issue and Merge Request
#
module Votes
  # Return the number of +1 comments (upvotes)
  def upvotes
    notes.select(&:upvote?).size
  end

  def upvotes_in_percent
    if votes_count.zero?
      0
    else
      100.0 / votes_count * upvotes
    end
  end

  # Return the number of -1 comments (downvotes)
  def downvotes
    notes.select(&:downvote?).size
  end

  def downvotes_in_percent
    if votes_count.zero?
      0
    else
      100.0 - upvotes_in_percent
    end
  end

  # Return the total number of votes
  def votes_count
    upvotes + downvotes
  end
end