FIX: Should not generate payload until active webhooks are exist

app/models/concerns/has_destroyed_web_hook.rb

@@ -7,7 +7,7 @@ module HasDestroyedWebHook
 
   def enqueue_destroyed_web_hook
     type = self.class.name.underscore.to_sym
-    payload = WebHook.generate_payload(type, self)
+    payload = WebHook.generate_payload(type, self) if WebHook.active_web_hooks(type).exists?
     yield
     WebHook.enqueue_hooks(type, "#{type}_destroyed".to_sym,
       id: id,

lib/post_destroyer.rb

@@ -45,12 +45,12 @@ class PostDestroyer
   end
 
   def destroy
-    payload = WebHook.generate_payload(:post, @post)
+    payload = WebHook.generate_payload(:post, @post) if WebHook.active_web_hooks(:post).exists?
     topic = @post.topic
 
     if @post.is_first_post? && topic
       topic_view = TopicView.new(topic.id, Discourse.system_user)
-      topic_payload = WebHook.generate_payload(:topic, topic_view, WebHookTopicViewSerializer)
+      topic_payload = WebHook.generate_payload(:topic, topic_view, WebHookTopicViewSerializer) if WebHook.active_web_hooks(:topic).exists?
     end
 
     delete_removed_posts_after = @opts[:delete_removed_posts_after] || SiteSetting.delete_removed_posts_after

spec/models/web_hook_spec.rb

@@ -125,10 +125,13 @@ describe WebHook do
     end
 
     describe 'when there are no active hooks' do
-      it 'should not enqueue anything' do
+      it 'should not generate payload and enqueue anything' do
         topic_web_hook.destroy!
         post = PostCreator.create(user, raw: 'post', title: 'topic', skip_validations: true)
         expect(Jobs::EmitWebHookEvent.jobs.length).to eq(0)
+
+        WebHook.expects(:generate_payload).times(0)
+        PostDestroyer.new(admin, post).destroy
       end
     end
 
@@ -384,6 +387,12 @@ describe WebHook do
       expect(payload["id"]).to eq(tag.id)
     end
 
+    it 'should not generate payload if webhooks not exist' do
+      WebHook.expects(:generate_payload).times(0)
+      tag = Fabricate(:tag)
+      tag.destroy!
+    end
+
     it 'should enqueue the right hooks for flag events' do
       post = Fabricate(:post)
       admin = Fabricate(:admin)