class User
  def initialize(admin: true)
    @admin = admin
  end

  attr_reader :admin

  def admin?
    admin == true
  end
end

class Foo
  def initialize(user)
    @user = user
  end

  def foo
    @foo ||= @user.admin? ? :do_admin : :do_normal
  end

  def do_admin
    'i am an admin'
  end

  def do_normal
    'i am not an admin'
  end
end

u = User.new(admin: false)
f = Foo.new(u)
puts f.send(f.foo)