Example code for tracker number of consecutive days a User performs a Session

streak-tracker.rb

class User < ApplicationRecord
	has_many :sessions, -> {order "created_at DESC"}

    def streak

        streak_count = 0
        today = Time.now.to_date

        dates_array = self.sessions.map do | session |
            session.created_at.to_date
        end
      
        unique_dates = dates_array.uniq

		    unique_dates.reduce(today) do | memo, date |

			    yesterday = memo.yesterday.to_date

            if date == yesterday || date == today
		        streak_count += 1
                memo = date
		    end
	    end

        streak_count
	end
end