feature_scanner.rb

require 'strscan'

singleton = <<EOS
Feature: Singletonz
  Scenario: Oh hai
    Given what is this here

%_FEATURE_END_%
EOS

multi =<<EOS
Feature: Foo
  Scenario: bar
    Given blah

%_FEATURE_END_%

Feature: Bar
  Scenario: blargle
    Given fooble

%_FEATURE_END_%

Feature: Boogle
  Scenario: mople
    When floogle

%_FEATURE_END_%
EOS

class FeatureScanner
  FEATURE_END = /%_FEATURE_END_%/

  def scan(input)
    features = []
    scanner = StringScanner.new(input)

    if scanner.exist?(FEATURE_END)
      loop do
        feature = scanner.scan_until(FEATURE_END)
        break unless feature
        features << clean_feature(feature)
      end
    else
      features << scanner.string
    end

    features
  end

  def clean_feature(str)
    str.chomp("%_FEATURE_END_%").strip
  end
end

f = FeatureScanner.new
p f.scan(multi)
p f.scan(singleton)