log exceptions correctly

Author: mileszim

lib/rails_semantic_logger/action_mailer/log_subscriber.rb

@@ -5,18 +5,28 @@ module RailsSemanticLogger
   module ActionMailer
     class LogSubscriber < ::ActiveSupport::LogSubscriber
       def deliver(event)
+        ex = event.payload[:exception_object]
         message_id = event.payload[:message_id]
         duration = event.duration.round(1)
-        message = begin
-         if event.payload[:perform_deliveries]
-            "Delivered mail #{message_id} (#{duration}ms)"
-          else
-            "Skipped delivery of mail #{message_id} as `perform_deliveries` is false"
+        if ex
+         log_with_formatter event: event, log_duration: true, level: :error do |fmt|
+            {
+              message: "Error delivering mail #{message_id} (#{duration}ms)",
+              exception: ex
+            }
+          end
+        else
+          message = begin
+          if event.payload[:perform_deliveries]
+              "Delivered mail #{message_id} (#{duration}ms)"
+            else
+              "Skipped delivery of mail #{message_id} as `perform_deliveries` is false"
+            end
+          end
+          log_with_formatter event: event, log_duration: true do |fmt|
+            { message: message }
           end
         end
-        log_with_formatter event: event do |fmt|
-          { message: message }
-        end          
       end
 
       # An email was generated.