Add `internal` attribute to routes

This is meant to provide a way for Action Cable, Sprockets, and possibly
other Rack applications to mark themselves as internal, and to exclude
themselves from the routing inspector, and thus `rails routes` / `rake
routes`.

I think this is the only way to have mounted Rack apps be marked as
internal, within AD/Journey. Another option would be to create an array
of regexes for internal apps, and then to iterate over that everytime a
request comes through. Also, I only had the first `add_route` method set
`internal`'s default to false, to avoid littering it all over the
codebase.

1 files changed, 2 insertions, 2 deletions

diff --git a/actionmailer/lib/action_mailer/railtie.rb b/actionmailer/lib/action_mailer/railtie.rb
index 22390c4953..6a633e4ce8 100644
--- a/actionmailer/lib/action_mailer/railtie.rb
+++ b/actionmailer/lib/action_mailer/railtie.rb
@@ -47,8 +47,8 @@ module ActionMailer
 
         if options.show_previews
           app.routes.prepend do
-            get '/rails/mailers'         => "rails/mailers#index"
-            get '/rails/mailers/*path'   => "rails/mailers#preview"
+            get '/rails/mailers'         => "rails/mailers#index", internal: true
+            get '/rails/mailers/*path'   => "rails/mailers#preview", internal: true
           end
         end