class HTMLProofer::Check::OpenGraph

def empty_content?
graph.node["content"].empty?

def missing_content?
graph.node["content"].nil?

def run
  @html.css('meta[property="og:url"], meta[property="og:image"]').each do |node|
    @open_graph = create_element(node)
    next if @open_graph.ignore?
    # does the open_graph exist?
    if missing_content?
      add_failure("open graph has no content attribute", line: @open_graph.line, content: @open_graph.content)
    elsif empty_content?
      add_failure("open graph content attribute is empty", line: @open_graph.line, content: @open_graph.content)
    elsif !@open_graph.url.valid?
      add_failure("#{@open_graph.src} is an invalid URL", line: @open_graph.line)
    elsif @open_graph.url.protocol_relative?
      add_failure("open graph link #{@open_graph.url} is a protocol-relative URL, use explicit https:// instead",
        line: @open_graph.line, content: @open_graph.content)
    elsif @open_graph.url.remote?
      add_to_external_urls(@open_graph.url, @open_graph.line)
    else
      add_failure("internal open graph #{@open_graph.url.raw_attribute} does not exist", line: @open_graph.line,
        content: @open_graph.content) unless @open_graph.url.exists?
    end
  end
  external_urls
end