discourse/spec/components/crawler_detection_spec.rb

# frozen_string_literal: true

require 'rails_helper'

describe CrawlerDetection do

  def crawler!(user_agent, via = nil)
    if (!CrawlerDetection.crawler?(user_agent, via))
      raise "#{user_agent} should be a crawler!"
    end
  end

  def not_crawler!(s)
    if CrawlerDetection.crawler?(s)
      raise "#{s} should not be a crawler!"
    end
  end

  describe "crawler?" do

    it "can be amended via site settings" do
      SiteSetting.crawler_user_agents = 'Mooble|Kaboodle+*'

      crawler! "Mozilla/5.0 Safari (compatible; Kaboodle+*/2.1; +http://www.google.com/bot.html)"
      crawler! "Mozilla/5.0 Safari (compatible; Mooble+*/2.1; +http://www.google.com/bot.html)"
      not_crawler! "Mozilla/5.0 Safari (compatible; Gooble+*/2.1; +http://www.google.com/bot.html)"
    end

    it "returns true for crawler user agents" do
      # https://support.google.com/webmasters/answer/1061943?hl=en
      crawler! "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
      crawler! "Googlebot/2.1 (+http://www.google.com/bot.html)"
      crawler! "Googlebot-News"
      crawler! "Googlebot-Image/1.0"
      crawler! "Googlebot-Video/1.0"
      crawler! "(compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)"
      crawler! "Mozilla/5.0 (iPhone; CPU iPhone OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5376e Safari/8536.25 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
      crawler! "(compatible; Mediapartners-Google/2.1; +http://www.google.com/bot.html)"
      crawler! "Mediapartners-Google"
      crawler! "AdsBot-Google (+http://www.google.com/adsbot.html)"
      crawler! "Twitterbot"
      crawler! "facebookexternalhit/1.1 (+http(s)://www.facebook.com/externalhit_uatext.php)"
      crawler! "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)"
      crawler! "Baiduspider+(+http://www.baidu.com/search/spider.htm)"
      crawler! "Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)"
      crawler! "Pingdom.com_bot_version_1.4_(http://www.pingdom.com/)"
      crawler! "LogicMonitor SiteMonitor/1.0"
      crawler! "Java/1.8.0_151"
      crawler! "Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)"
      crawler! "Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3694.0 Mobile Safari/537.36 Chrome-Lighthouse"
    end

    it "returns true when VIA header contains 'web.archive.org'" do
      crawler! "Mozilla/5.0 (compatible; archive.org_bot +http://archive.org/details/archive.org_bot)"
      crawler! "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36", "HTTP/1.0 web.archive.org (Wayback Save Page)"
      crawler! "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36", "Mozilla/5.0 (compatible; archive.org_bot; Wayback Machine Live Record; http://archive.org/details/archive.org_bot), 1.1 warcprox"
    end

    it "returns false for non-crawler user agents" do
      not_crawler! "Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1667.0 Safari/537.36"
      not_crawler! "Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko"
      not_crawler! "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)"
      not_crawler! "Mozilla/5.0 (iPad; CPU OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5355d Safari/8536.25"
      not_crawler! "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:25.0) Gecko/20100101 Firefox/25.0"
      not_crawler! "Mozilla/5.0 (Linux; U; Android 4.0.3; ko-kr; LG-L160L Build/IML74K) AppleWebkit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30"
      not_crawler! "Mozilla/5.0 (Linux; Android 6.0; CUBOT DINOSAUR Build/MRA58K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Mobile Safari/537.36+"
      not_crawler! "DiscourseAPI Ruby Gem 0.19.0"
    end

  end

  describe 'allow_crawler?' do
    it 'returns true if allowlist and blocklist are blank' do
      expect(CrawlerDetection.allow_crawler?('Googlebot/2.1 (+http://www.google.com/bot.html)')).to eq(true)
    end

    context 'allowlist is set' do
      before do
        SiteSetting.allowed_crawler_user_agents = 'Googlebot|Twitterbot'
      end

      it 'returns true for matching user agents' do
        expect(CrawlerDetection.allow_crawler?('Googlebot/2.1 (+http://www.google.com/bot.html)')).to eq(true)
        expect(CrawlerDetection.allow_crawler?('Googlebot-Image/1.0')).to eq(true)
        expect(CrawlerDetection.allow_crawler?('Twitterbot')).to eq(true)
      end

      it 'returns false for user agents that do not match' do
        expect(CrawlerDetection.allow_crawler?('facebookexternalhit/1.1 (+http(s)://www.facebook.com/externalhit_uatext.php)')).to eq(false)
        expect(CrawlerDetection.allow_crawler?('Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)')).to eq(false)
        expect(CrawlerDetection.allow_crawler?('')).to eq(false)
      end

      context 'and blocklist is set' do
        before do
          SiteSetting.blocked_crawler_user_agents = 'Googlebot-Image'
        end

        it 'ignores the blocklist' do
          expect(CrawlerDetection.allow_crawler?('Googlebot-Image/1.0')).to eq(true)
        end
      end
    end

    context 'blocklist is set' do
      before do
        SiteSetting.blocked_crawler_user_agents = 'Googlebot|Twitterbot'
      end

      it 'returns true for crawlers that do not match' do
        expect(CrawlerDetection.allow_crawler?('Mediapartners-Google')).to eq(true)
        expect(CrawlerDetection.allow_crawler?('facebookexternalhit/1.1 (+http(s)://www.facebook.com/externalhit_uatext.php)')).to eq(true)
        expect(CrawlerDetection.allow_crawler?('')).to eq(true)
      end

      it 'returns false for user agents that match' do
        expect(CrawlerDetection.allow_crawler?('Googlebot/2.1 (+http://www.google.com/bot.html)')).to eq(false)
        expect(CrawlerDetection.allow_crawler?('Googlebot-Image/1.0')).to eq(false)
        expect(CrawlerDetection.allow_crawler?('Twitterbot')).to eq(false)
      end
    end
  end

  describe 'is_blocked_crawler?' do
    it 'is false if user agent is a crawler and no allowlist or blocklist is defined' do
      expect(CrawlerDetection.is_blocked_crawler?('Twitterbot')).to eq(false)
    end

    it 'is false if user agent is not a crawler and no allowlist or blocklist is defined' do
      expect(CrawlerDetection.is_blocked_crawler?('Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36')).to eq(false)
    end

    it 'is true if user agent is a crawler and is not allowlisted' do
      SiteSetting.allowed_crawler_user_agents = 'Googlebot'
      expect(CrawlerDetection.is_blocked_crawler?('Twitterbot')).to eq(true)
    end

    it 'is false if user agent is not a crawler and there is a allowlist' do
      SiteSetting.allowed_crawler_user_agents = 'Googlebot'
      expect(CrawlerDetection.is_blocked_crawler?('Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36')).to eq(false)
    end

    it 'is true if user agent is a crawler and is blocklisted' do
      SiteSetting.blocked_crawler_user_agents = 'Twitterbot'
      expect(CrawlerDetection.is_blocked_crawler?('Twitterbot')).to eq(true)
    end

    it 'is true if user agent is a crawler and is not blocklisted' do
      SiteSetting.blocked_crawler_user_agents = 'Twitterbot'
      expect(CrawlerDetection.is_blocked_crawler?('Googlebot')).to eq(false)
    end

    it 'is false if user agent is not a crawler and blocklist is defined' do
      SiteSetting.blocked_crawler_user_agents = 'Mozilla'
      expect(CrawlerDetection.is_blocked_crawler?('Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36')).to eq(false)
    end

    it 'is true if user agent is missing and allowlist is defined' do
      SiteSetting.allowed_crawler_user_agents = 'Googlebot'
      expect(CrawlerDetection.is_blocked_crawler?('')).to eq(true)
      expect(CrawlerDetection.is_blocked_crawler?(nil)).to eq(true)
    end

    it 'is false if user agent is missing and blocklist is defined' do
      SiteSetting.blocked_crawler_user_agents = 'Googlebot'
      expect(CrawlerDetection.is_blocked_crawler?('')).to eq(false)
      expect(CrawlerDetection.is_blocked_crawler?(nil)).to eq(false)
    end
  end
end