[deploy] Skip updating a root comment if it doesnt exist (#7080)

app/models/comment.rb

@@ -185,7 +185,11 @@ class Comment < ApplicationRecord
   end
 
   def expire_root_fragment
-    root.touch
+    if root_exists?
+      root.touch
+    else
+      touch
+    end
   end
 
   def create_first_reaction
@@ -214,6 +218,10 @@ class Comment < ApplicationRecord
     expire_root_fragment
   end
 
+  def root_exists?
+    ancestry && Comment.exists?(id: ancestry)
+  end
+
   def send_email_notification
     Comments::SendEmailNotificationWorker.perform_async(id)
   end

app/workers/comments/calculate_score_worker.rb

@@ -12,7 +12,7 @@ module Comments
       spaminess_rating = BlackBox.calculate_spaminess(comment)
 
       comment.update_columns(score: score, spaminess_rating: spaminess_rating)
-      comment.root.save! unless comment.is_root?
+      comment.root.save! if !comment.is_root? && comment.root_exists?
     end
   end
 end

spec/workers/comments/calculate_score_worker_spec.rb

@@ -30,6 +30,7 @@ RSpec.describe Comments::CalculateScoreWorker, type: :worker do
         allow(root_comment).to receive(:save!)
         allow(child_comment).to receive(:update_columns)
         allow(child_comment).to receive(:is_root?).and_return(false)
+        allow(child_comment).to receive(:root_exists?).and_return(true)
         allow(child_comment).to receive(:root).and_return(root_comment)
         allow(Comment).to receive(:find_by).with(id: 1).and_return(child_comment)