value objects to avoid primitive obsession

after.rb

class Title
  def initialize(title)
    @title = title
  end

  def to_seniority
    @title.include?('junior') ? 'junior' : nil
  end
end

title = 'some job title'

seniority = Title.new(title).to_seniority

before.rb

title = 'some job title'

seniority = title.include?('junior') ? 'junior' : nil

why_better_abstracted_business_logic.rb

class Title
  def initialize(title)
    @title = title
  end

  def to_seniority
    return 'junior' if @title.include?('junior')
    return 'senior' if @title.include?('senior')
    return 'manager' if @title.include?('manager')
    nil
  end
end

# code remains unchanged!
seniority = Title.new(title).to_seniority  

why_better_easily_extended_class.rb

class Title
  def initialize(title)
    @title = title
  end

  def to_seniority
    @title.include?('junior') ? 'junior' : nil
  end

  # easy to add a new method to the class!
  def to_specialisation
    return 'software engineer' if @title.include?('software')
    return 'data scientist' if @title.include?('data sci')
    nil
  end
end

specialisation = Title.new(title).to_specialisation

why_better_readability.rb

def title_to_seniority(title)
  title.include?('junior') ? 'junior' : nil
end

seniority = title_to_seniority(title)

https://adriangohjw.github.io/posts/2021/05/26/value-objects-to-avoid-primitive-obsession.html