rexml xpath matcher for rspec

have_xml.rb

# cheap mans xpath matcher
# inspired by: https://gist.github.com/faun/4279964
RSpec::Matchers.define :have_xml do |xpath, text|
  match do |body|
    doc = REXML::Document.new(body)
    nodes = REXML::XPath.match(doc, xpath)
    if text
      nodes.each do |node|
        node.content.should == text
      end
    end
    nodes.empty? ? false : true
  end

  failure_message_for_should do |body|
    "expected to find xml tag #{xpath} in:\n#{body}"
  end

  failure_message_for_should_not do |response|
    "expected not to find xml tag #{xpath} in:\n#{body}"
  end

  description do
    "have xml tag #{xpath}"
  end
end