Merge pull request #24161 from Sen-Zhang/restore_application_mailer

regenerate application_mailer.rb if it is missing

2 files changed, 10 insertions, 0 deletions

diff --git a/actionmailer/lib/rails/generators/mailer/mailer_generator.rb b/actionmailer/lib/rails/generators/mailer/mailer_generator.rb
index ae5757917e..f86d43be61 100644
--- a/actionmailer/lib/rails/generators/mailer/mailer_generator.rb
+++ b/actionmailer/lib/rails/generators/mailer/mailer_generator.rb
@@ -9,6 +9,12 @@ module Rails
 
       def create_mailer_file
         template "mailer.rb", File.join('app/mailers', class_path, "#{file_name}_mailer.rb")
+
+        in_root do
+          if self.behavior == :invoke && !File.exist?('app/mailers/application_mailer.rb')
+            template 'application_mailer.rb', 'app/mailers/application_mailer.rb'
+          end
+        end
       end
 
       hook_for :template_engine, :test_framework
diff --git a/actionmailer/lib/rails/generators/mailer/templates/application_mailer.rb b/actionmailer/lib/rails/generators/mailer/templates/application_mailer.rb
new file mode 100644
index 0000000000..02e8d3e454
--- /dev/null
+++ b/actionmailer/lib/rails/generators/mailer/templates/application_mailer.rb
@@ -0,0 +1,4 @@
+class ApplicationMailer < ActionMailer::Base
+  default from: 'from@example.com'
+  layout :mailer
+end