Decorate a class

lib/base_decorator.rb

@@ -0,0 +1,14 @@
+require_relative './nameable'
+
+class BaseDecorator < Nameable
+  attr_accessor :nameable
+
+  def initialize(nameable)
+    super()
+    @nameable = nameable
+  end
+
+  def correct_name
+    @nameable.correct_name
+  end
+end

lib/capitalize_decorator.rb

@@ -0,0 +1,7 @@
+require_relative './base_decorator'
+
+class CapitalizeDecorator < BaseDecorator
+  def correct_name
+    @nameable.correct_name.capitalize
+  end
+end

lib/nameable.rb

@@ -0,0 +1,5 @@
+class Nameable
+  def correct_name
+    raise NotImplementedError, "#{self.class} has not implemented method '#{__method__}'"
+  end
+end

lib/person.rb

@@ -1,8 +1,11 @@
-class Person
+require_relative './nameable'
+
+class Person < Nameable
   attr_reader :id
   attr_accessor :name, :age
 
   def initialize(age, name = 'Unknown', parent_permission: true)
+    super()
     @id = Random.rand(1..1000)
     @name = name
     @age = age
@@ -24,4 +27,8 @@ def can_use_service?
 
     false
   end
+
+  def correct_name
+    @name
+  end
 end

lib/trimmer_decorator.rb

@@ -0,0 +1,11 @@
+require_relative './base_decorator'
+
+class TrimmerDecorator < BaseDecorator
+  def correct_name
+    name = @nameable.correct_name
+    size = name.size
+    return name.slice!(0..9) if size > 10
+
+    name
+  end
+end