be_like.rb

module Matchers
  class BeLike
    def initialize(expected)
      @expected = expected.gsub(/\s+/, ' ').strip
    end

    def matches?(actual)
      @actual = actual.gsub(/\s+/, ' ').strip
      @expected == @actual
    end

    def failure_message
      "expected\n#{@actual}\nto be like\n#{@expected}"
    end

    def negative_failure_message
      "expected\n#{@actual}\nto be unlike\n#{@expected}"
    end
  end

  def be_like(expected)
    BeLike.new(expected)
  end
end

example_spec.rb

it "should render to XML with attributes" do
  @schema.define('FoodMart') do
    description 'Demo "FoodMart" schema'
  end
  @schema.to_xml.should be_like <<-XML
  <?xml version="1.0"?>
  <Schema name="FoodMart" description="Demo &quot;FoodMart&quot; schema"/>
  XML
end