check_css_assets.rb

#!/usr/bin/env ruby
# this script takes a URL and verifies that
# every css file included loads correctly

require 'open-uri'
require 'nokogiri'
require 'pry' if $DEBUG

url = ARGV.shift || 'https://ifttt.com'
doc = Nokogiri::HTML(open(url).read)

# iterate over every link tag in the doc
css_urls = doc.xpath('//link').map do |link_tags|
  link_tags.attributes['href'].value
end.select do |link|
  # select only the css files
  link =~ /css$/
end

binding.pry if $DEBUG

# attempt to open every css file
css_urls.each do |css_url|
  begin
    open css_url
  rescue Exception => e
    # print an error and exit if we have issues
    puts "Error loading #{css_url}: #{e.message}"
    puts e.backtrace if $DEBUG
    exit 2
  end
end