string_interpolation_monkeypatch.rb

# This relates to the issue described at:
#   https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/4709

class String
  def %(args)
    if args.kind_of?(Hash)
      dup.gsub(INTERPOLATION_PATTERN_WITH_ESCAPE) do |match|
        if match == '%%'
          '%'
        else
          key = ($1 || $2).to_sym
          raise KeyError unless args.has_key?(key)
          $3 ? sprintf("%#{$3}", args[key]) : args[key]
        end
      end
    elsif self =~ INTERPOLATION_PATTERN
      raise ArgumentError.new('one hash required')
    else
      result = gsub(/%%?([{<])/, '%%\1')
      result.send :'interpolate_without_ruby_19_syntax', args
    end
  end
end