Make handler metric params more explicit

lib/gitlab/email/handler/base_handler.rb

@@ -16,6 +16,10 @@ module Gitlab
         def execute
           raise NotImplementedError
         end
+
+        def metrics_params
+          { handler: self.class.name }
+        end
       end
     end
   end

lib/gitlab/email/handler/create_issue_handler.rb

@@ -1,4 +1,3 @@
-
 require 'gitlab/email/handler/base_handler'
 
 module Gitlab
@@ -37,6 +36,10 @@ module Gitlab
           @project ||= Project.find_by_full_path(project_path)
         end
 
+        def metrics_params
+          super.merge(project: project)
+        end
+
         private
 
         def create_issue

lib/gitlab/email/handler/create_note_handler.rb

@@ -28,6 +28,10 @@ module Gitlab
             record_name: 'comment')
         end
 
+        def metrics_params
+          super.merge(project: project)
+        end
+
         private
 
         def author

lib/gitlab/email/handler/unsubscribe_handler.rb

@@ -19,6 +19,10 @@ module Gitlab
           noteable.unsubscribe(sent_notification.recipient)
         end
 
+        def metrics_params
+          super.merge(project: project)
+        end
+
         private
 
         def sent_notification

lib/gitlab/email/receiver.rb

@@ -1,4 +1,3 @@
-
 require_dependency 'gitlab/email/handler'
 
 # Inspired in great part by Discourse's Email::Receiver
@@ -32,9 +31,7 @@ module Gitlab
 
         raise UnknownIncomingEmail unless handler
 
-        Gitlab::Metrics.add_event(:receive_email,
-                                  project: handler.try(:project),
-                                  handler: handler.class.name)
+        Gitlab::Metrics.add_event(:receive_email, handler.metrics_params)
 
         handler.execute
       end