Don't remove all line endings from routes.rb

When there is a single scaffold in the routes.rb with no other lines
then revoking/destroying it will create a routes.rb file with a syntax
error. This is because the sentinel for the Thor `route` action didn't
include the newline but the logged route code did.

The fix is to add the newline to the sentinel and remove it from the
the logged route code.

Fixes #15913.

1 files changed, 2 insertions, 2 deletions

diff --git a/railties/lib/rails/generators/actions.rb b/railties/lib/rails/generators/actions.rb
index e35015f630..e39a45f4c9 100644
--- a/railties/lib/rails/generators/actions.rb
+++ b/railties/lib/rails/generators/actions.rb
@@ -218,10 +218,10 @@ module Rails
       #   route "root 'welcome#index'"
       def route(routing_code)
         log :route, routing_code
-        sentinel = /\.routes\.draw do\s*$/
+        sentinel = /\.routes\.draw do\s*\n/m
 
         in_root do
-          inject_into_file 'config/routes.rb', "\n  #{routing_code}", { after: sentinel, verbose: false }
+          inject_into_file 'config/routes.rb', "  #{routing_code}", { after: sentinel, verbose: false }
         end
       end