Add `:args` to `process.action_mailer` event

actionmailer/CHANGELOG.md

+*   Add `:args` to `process.action_mailer` event.
+
+    *Yuji Yaginuma*
+
 *   Add parameterized invocation of mailers as a way to share before filters and defaults between actions.
     See ActionMailer::Parameterized for a full example of the benefit.
 

actionmailer/lib/action_mailer/base.rb

@@ -598,7 +598,8 @@ def initialize
     def process(method_name, *args) #:nodoc:
       payload = {
         mailer: self.class.name,
-        action: method_name
+        action: method_name,
+        args: args
       }
 
       ActiveSupport::Notifications.instrument("process.action_mailer", payload) do

actionmailer/test/base_test.rb

@@ -834,6 +834,25 @@ def a_callback
     assert_equal "special indeed!", mail["X-Special-Header"].to_s
   end
 
+  test "notification for process" do
+    begin
+      events = []
+      ActiveSupport::Notifications.subscribe("process.action_mailer") do |*args|
+        events << ActiveSupport::Notifications::Event.new(*args)
+      end
+
+      BaseMailer.welcome(body: "Hello there").deliver_now
+
+      assert_equal 1, events.length
+      assert_equal "process.action_mailer", events[0].name
+      assert_equal "BaseMailer", events[0].payload[:mailer]
+      assert_equal :welcome, events[0].payload[:action]
+      assert_equal [{ body: "Hello there" }], events[0].payload[:args]
+    ensure
+      ActiveSupport::Notifications.unsubscribe "process.action_mailer"
+    end
+  end
+
   private
 
     # Execute the block setting the given values and restoring old values after