add new commenting secion for deliver_later_option and add a small te…

…st case for deliver_later_option

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