Merge pull request rails#49083 from 1st8/actionmailer-log-subscriber-…

…log-errors

Log delivery errors in ActionMailer::LogSubscriber

actionmailer/lib/action_mailer/log_subscriber.rb

@@ -11,8 +11,9 @@ class LogSubscriber < ActiveSupport::LogSubscriber
     # An email was delivered.
     def deliver(event)
       info do
-        perform_deliveries = event.payload[:perform_deliveries]
-        if perform_deliveries
+        if exception = event.payload[:exception_object]
+          "Failed delivery of mail #{event.payload[:message_id]} error_class=#{exception.class} error_message=#{exception.message.inspect}"
+        elsif event.payload[:perform_deliveries]
           "Delivered mail #{event.payload[:message_id]} (#{event.duration.round(1)}ms)"
         else
           "Skipped delivery of mail #{event.payload[:message_id]} as `perform_deliveries` is false"

actionmailer/test/log_subscriber_test.rb

@@ -13,9 +13,12 @@ def setup
     ActionMailer::LogSubscriber.attach_to :action_mailer
   end
 
-  class TestMailer < ActionMailer::Base
-    def receive(mail)
-      # Do nothing
+  class BogusDelivery
+    def initialize(*)
+    end
+
+    def deliver!(mail)
+      raise "failed"
     end
   end
 
@@ -50,4 +53,17 @@ def test_deliver_message_when_perform_deliveries_is_false
   ensure
     BaseMailer.deliveries.clear
   end
+
+  def test_deliver_message_when_exception_happened
+    previous_delivery_method = BaseMailer.delivery_method
+    BaseMailer.delivery_method = BogusDelivery
+
+    assert_raises(RuntimeError) { BaseMailer.welcome(message_id: "123@abc").deliver_now }
+    wait
+
+    assert_equal(1, @logger.logged(:info).size)
+    assert_equal('Failed delivery of mail 123@abc error_class=RuntimeError error_message="failed"', @logger.logged(:info).first)
+  ensure
+    BaseMailer.delivery_method = previous_delivery_method
+  end
 end