user.rb

# Improve / Fix as many things in the code below
# Answers should be sent to [email protected]
# Good luck

class User < ActiveRecord::Base
  validates_presence_of :name, :email, :date_of_birth, :age_category

  before_save do
    age = (Time.now - date_of_birth).year
    if age < 10 age_category = 'child'
    elsif age < 18 age_category = 'teenager'
    elsif age < 24 age_category = 'young'
    elsif age < 54 age_category = 'adult'
    else age_category = 'senior'
  end
end