when writing cache, remove elements from the user agents list. also return a message and content type when blocking a crawler.

app/models/web_crawler_request.rb

@@ -30,9 +30,9 @@ class WebCrawlerRequest < ActiveRecord::Base
     self.last_flush = Time.now.utc
 
     date = date.to_date
+    ua_list_key = user_agent_list_key(date)
 
-    $redis.smembers(user_agent_list_key(date)).each do |user_agent, _|
-
+    while user_agent = $redis.spop(ua_list_key)
       val = get_and_reset(redis_key(user_agent, date))
 
       next if val == 0
@@ -57,7 +57,7 @@ class WebCrawlerRequest < ActiveRecord::Base
       $redis.del redis_key(user_agent, date)
     end
 
-    $redis.del list_key
+    $redis.del(list_key)
   end
 
   protected

lib/middleware/request_tracker.rb

@@ -167,7 +167,7 @@ class Middleware::RequestTracker
 
     if block_crawler(request)
       log_request = false
-      result = [403, {}, []]
+      result = [403, { 'Content-Type' => 'text/plain' }, ['Crawler is not allowed']]
       return result
     end
 

spec/components/middleware/request_tracker_spec.rb

@@ -291,7 +291,7 @@ describe Middleware::RequestTracker do
 
     def expect_blocked_response(status, _, response)
       expect(status).to eq(403)
-      expect(response).to be_blank
+      expect(response).to eq(['Crawler is not allowed'])
     end
 
     it "applies whitelisted_crawler_user_agents correctly" do