[WIP] Issue #4209 - Add deliver_later option in send_devise_notification

lib/devise.rb

@@ -286,6 +286,10 @@ module Test
   mattr_accessor :token_generator
   @@token_generator = nil
 
+  # Store devise notification delivery method, default is deliver now
+  mattr_accessor :deliver_later_option
+  @@deliver_later_option = false
+
   # Default way to set up Devise. Run rails generate devise_install to create
   # a fresh initializer with all configuration values.
   def self.setup

lib/devise/models/authenticatable.rb

@@ -129,6 +129,10 @@ def devise_mailer
         Devise.mailer
       end
 
+      def delivery_method
+        Devise.deliver_later_option ? :deliver_later : :deliver_now
+      end
+
       # This is an internal method called every time Devise needs
       # to send a notification/mail. This can be overridden if you
       # need to customize the e-mail delivery logic. For instance,
@@ -187,8 +191,9 @@ def devise_mailer
       def send_devise_notification(notification, *args)
         message = devise_mailer.send(notification, self, *args)
         # Remove once we move to Rails 4.2+ only.
+
         if message.respond_to?(:deliver_now)
-          message.deliver_now
+          message.send(delivery_method)
         else
           message.deliver
         end

lib/generators/templates/devise.rb

@@ -271,4 +271,9 @@
   # When using OmniAuth, Devise cannot automatically set OmniAuth path,
   # so you need to do it manually. For the users scope, it would be:
   # config.omniauth_path_prefix = '/my_engine/users/auth'
+
+  # ===> ActiveJob configuration
+  # If you want to use ActiveJob to diliver ActionMailer messages in the backgound,
+  # you can config deliver_later_option to true. Default is false
+  # config.deliver_later_option = true
 end

test/mailers/mailer_test.rb

@@ -15,4 +15,12 @@ def confirmation_instructions(record, token, opts = {})
 
     assert mail.content_transfer_encoding, "7bit"
   end
+
+  test "devise mailer should use deliver_later if deliver_later_option is true" do
+    swap Devise, deliver_later_option: true do
+      user = create_user
+      deliver_method = user.send(:delivery_method).to_s
+      assert_equal deliver_method, "deliver_later"
+    end
+  end
 end