REFACTOR: Prefer accessing instance variables directly.

* No need to wrap instance variables with another method to read it.
* Remove memoization that wasn't really memozing anything.

app/jobs/regular/emit_web_hook_event.rb

@@ -7,10 +7,12 @@ module Jobs
     RETRY_BACKOFF = 5
 
     def execute(args)
-      memoize_arguments(args)
+      @arguments = args
+      @retry_count = args[:retry_count] || 0
+      @web_hook = WebHook.find_by(id: @arguments[:web_hook_id])
       validate_arguments!
 
-      unless ping_event?(arguments[:event_type])
+      unless ping_event?(@arguments[:event_type])
         validate_argument!(:payload)
 
         return if webhook_inactive?
@@ -27,21 +29,16 @@ module Jobs
     def validate_arguments!
       validate_argument!(:web_hook_id)
       validate_argument!(:event_type)
-      raise Discourse::InvalidParameters.new(:web_hook_id) if web_hook.blank?
+      raise Discourse::InvalidParameters.new(:web_hook_id) if @web_hook.blank?
     end
 
     def validate_argument!(key)
-      raise Discourse::InvalidParameters.new(key) unless arguments[key].present?
+      raise Discourse::InvalidParameters.new(key) unless @arguments[key].present?
-    end
-
-    def memoize_arguments(args)
-      @arguments = args
-      @retry_count = @arguments[:retry_count] || 0
     end
 
     def send_webhook!
-      uri = URI(web_hook.payload_url.strip)
+      uri = URI(@web_hook.payload_url.strip)
-      conn = Excon.new(uri.to_s, ssl_verify_peer: web_hook.verify_certificate, retry_limit: 0)
+      conn = Excon.new(uri.to_s, ssl_verify_peer: @web_hook.verify_certificate, retry_limit: 0)
 
       web_hook_body = build_webhook_body
       web_hook_event = create_webhook_event(web_hook_body)
@@ -76,11 +73,13 @@ module Jobs
 
       case web_hook_response.status
       when 200..299
-        return
       when 404, 410
         if @retry_count >= MAX_RETRY_COUNT
-          web_hook.update_attribute(:active, false)
+          @web_hook.update!(active: false)
-          StaffActionLogger.new(Discourse.system_user).log_web_hook_deactivate(web_hook, web_hook_response.status)
+
+          StaffActionLogger
+            .new(Discourse.system_user)
+            .log_web_hook_deactivate(@web_hook, web_hook_response.status)
         end
       else
         retry_web_hook
@@ -92,14 +91,14 @@ module Jobs
         @retry_count += 1
         return if @retry_count > MAX_RETRY_COUNT
         delay = RETRY_BACKOFF**(@retry_count - 1)
-        Jobs.enqueue_in(delay.minutes, :emit_web_hook_event, arguments)
+        Jobs.enqueue_in(delay.minutes, :emit_web_hook_event, @arguments)
       end
     end
 
     def publish_webhook_event(web_hook_event)
-      MessageBus.publish("/web_hook_events/#{web_hook.id}", {
+      MessageBus.publish("/web_hook_events/#{@web_hook.id}", {
         web_hook_event_id: web_hook_event.id,
-        event_type: arguments[:event_type]
+        event_type: @arguments[:event_type]
       }, user_ids: User.human_users.staff.pluck(:id))
     end
 
@@ -108,39 +107,27 @@ module Jobs
     end
 
     def webhook_inactive?
-      !web_hook.active?
+      !@web_hook.active?
     end
 
     def group_webhook_invalid?
-      web_hook.group_ids.present? && (arguments[:group_id].present? ||
+      @web_hook.group_ids.present? && (@arguments[:group_id].present? ||
-        !web_hook.group_ids.include?(arguments[:group_id]))
+        !@web_hook.group_ids.include?(@arguments[:group_id]))
     end
 
     def category_webhook_invalid?
-      web_hook.category_ids.present? && (!arguments[:category_id].present? ||
+      @web_hook.category_ids.present? && (!@arguments[:category_id].present? ||
-        !web_hook.category_ids.include?(arguments[:category_id]))
+        !@web_hook.category_ids.include?(@arguments[:category_id]))
     end
 
     def tag_webhook_invalid?
-      web_hook.tag_ids.present? && (arguments[:tag_ids].blank? ||
+      @web_hook.tag_ids.present? && (@arguments[:tag_ids].blank? ||
-        (web_hook.tag_ids & arguments[:tag_ids]).blank?)
+        (@web_hook.tag_ids & @arguments[:tag_ids]).blank?)
-    end
-
-    def arguments
-      @arguments
-    end
-
-    def parsed_payload
-      @parsed_payload ||= JSON.parse(arguments[:payload])
-    end
-
-    def web_hook
-      @web_hook ||= WebHook.find_by(id: arguments[:web_hook_id])
     end
 
     def build_webhook_headers(uri, web_hook_body, web_hook_event)
       content_type =
-        case web_hook.content_type
+        case @web_hook.content_type
         when WebHook.content_types['application/x-www-form-urlencoded']
           'application/x-www-form-urlencoded'
         else
@@ -156,13 +143,13 @@ module Jobs
         'User-Agent' => "Discourse/#{Discourse::VERSION::STRING}",
         'X-Discourse-Instance' => Discourse.base_url,
         'X-Discourse-Event-Id' => web_hook_event.id,
-        'X-Discourse-Event-Type' => arguments[:event_type]
+        'X-Discourse-Event-Type' => @arguments[:event_type]
       }
 
-      headers['X-Discourse-Event'] = arguments[:event_name] if arguments[:event_name].present?
+      headers['X-Discourse-Event'] = @arguments[:event_name] if @arguments[:event_name].present?
 
-      if web_hook.secret.present?
+      if @web_hook.secret.present?
-        headers['X-Discourse-Event-Signature'] = "sha256=#{OpenSSL::HMAC.hexdigest("sha256", web_hook.secret, web_hook_body)}"
+        headers['X-Discourse-Event-Signature'] = "sha256=#{OpenSSL::HMAC.hexdigest("sha256", @web_hook.secret, web_hook_body)}"
       end
 
       headers
@@ -171,10 +158,10 @@ module Jobs
     def build_webhook_body
       body = {}
 
-      if ping_event?(arguments[:event_type])
+      if ping_event?(@arguments[:event_type])
         body['ping'] = "OK"
       else
-        body[arguments[:event_type]] = parsed_payload
+        body[@arguments[:event_type]] = JSON.parse(@arguments[:payload])
       end
 
       new_body = Plugin::Filter.apply(:after_build_web_hook_body, self, body)
@@ -182,7 +169,7 @@ module Jobs
     end
 
     def create_webhook_event(web_hook_body)
-      WebHookEvent.create!(web_hook_id: web_hook.id, payload: web_hook_body)
+      WebHookEvent.create!(web_hook: @web_hook, payload: web_hook_body)
     end
 
   end