Merge pull request #52215 from p8/railties/document-action-mailer-perform-caching

Document `action_mailer.perform_caching` in environment files. [ci-skip]

railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt

@@ -42,6 +42,8 @@ Rails.application.configure do
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false
 
+  # Disable caching for Action Mailer templates even if Action Controller
+  # caching is enabled.
   config.action_mailer.perform_caching = false
 
   config.action_mailer.default_url_options = { host: "localhost", port: 3000 }

railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt

@@ -85,6 +85,8 @@ Rails.application.configure do
 
   <%- end -%>
   <%- unless options.skip_action_mailer? -%>
+  # Disable caching for Action Mailer templates even if Action Controller
+  # caching is enabled.
   config.action_mailer.perform_caching = false
 
   # Ignore bad email addresses and do not raise email delivery errors.

railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt

@@ -37,6 +37,8 @@ Rails.application.configure do
 
   <%- end -%>
   <%- unless options.skip_action_mailer? -%>
+  # Disable caching for Action Mailer templates even if Action Controller
+  # caching is enabled.
   config.action_mailer.perform_caching = false
 
   # Tell Action Mailer not to deliver emails to the real world.