more-complex-matcher.rb

Spec::Matchers.create(:have_xpath) do
  matches do |rack, xpath|
    document = rack.body
    
    if rack.status < 200 || rack.status >= 300
      @error_text = rack.body
      false
    else
      @document = case document
      when LibXML::XML::Document, LibXML::XML::Node
        document
      when StringIO
        LibXML::XML::HTMLParser.string(document.string).parse
      else
        LibXML::XML::HTMLParser.string(document).parse
      end
      begin
        [email protected](xpath).empty?
      rescue LibXML::XML::XPath::InvalidPath
        @bad_xpath = true
        false
      end
    end
  end
  
  message do |not_string, rack, xpath|
    if @bad_xpath
      "the XPath '#{xpath}' was invalid"
    elsif @error_text
      "there was an error on your page:\n#{@error_text}"
    else
      "expected the following text #{not_string}to match the xpath '#{xpath}':\n\n#{@document}"
    end
  end
end

Spec::Matchers.create(:redirect_to) do
  expected_value do |location|
    url(location) if location.is_a?(Symbol)
  end
  
  matches do |rack, location|
    rack.status == 302 && rack.headers["Location"] == location
  end
  
  negative_failure_message do |rack, location|
    "Expected #{describe_request(rack)} not to redirect to " \
    "'#{location}' but it did."
  end
  
  failure_message do |rack, location|
    if rack.status != 302
      "Expected #{describe_request(rack)} to be a redirect, but " \
      "it returned status code #{rack.status}."
    elsif rack.headers["Location"] != location
      "Expected #{describe_request(rack)} to redirect to " \
      "'#{location}', but it redirected to #{rack.headers["Location"]}"
    end
  end
end