SimpleDelegator in Ruby

require 'delegate'

class User
  def born_on
    'July 21'
  end
end

class UserDecorator < SimpleDelegator
  def birth_year
    born_on
  end
end

decorated_user = UserDecorator.new(User.new)
p decorated_user.birth_year  #=> July 21

psych.rb in `parse': found a tab character that violate intendation while scanning a plain scalar at

You will not be able to go the rails console. Go to the root directory of the rails project and fire up an irb session:

1. require 'yaml'
2. YAML::ENGINE.yamler = 'psych'
3. YAML.load_file('config/your-config-file.yml')

Autocorrect yaml file syntax errors: s.gsub!(/\t/, ' ')

This will reproduce the problem. See the line number of row to find the syntax error. Fix it by changing the tab to space.