Ruby core extension for adding items conditionally to Arrays

array.rb

class Array
  
  # Inserts an object to the Array if condition is true
  #
  # object    - The object to insert.
  # condition - The condition to evaluate.
  #
  # Example:
  #   
  #  = content_tag(:div, class: ["user-username"].insert_if("active", @user.active)) do
  #    = @user.username
  #
  # Returns the same Array
  def insert_if(object, condition)
    tap { |array| array << object if condition } 
  end
  
end