class RSpecHtmlMatchers::HaveTag

def matches? document, &block
  @block = block if block
  document = document.html if defined?(Capybara::Session) && document.is_a?(Capybara::Session)
  case document
  when String
    @parent_scope = Nokogiri::HTML(document)
    @document     = document
  else
    @parent_scope  = document.current_scope
    @document      = @parent_scope.to_html
  end
  @current_scope = begin
                     @parent_scope.css(@tag)
                   # on jruby this produce exception if css was not found:
                   # undefined method `decorate' for nil:NilClass
                   rescue NoMethodError
                     Nokogiri::XML::NodeSet.new(Nokogiri::XML::Document.new)
                   end
  if tag_presents? and text_right? and count_right?
    @block.call(self) if @block
    true
  else
    false
  end
end