Of course we’ve known for a while to not use default routes in combination with restful routes. However, there is a hidden danger when dealing with Engines. I was doing what should have been a quick experiment with an Engine in Rails 2.3. So, I generated a default app.

  rails cereal
  rails fruits
  cd cereal
  script/generate scaffold cornflake

Then I follow the incantation to get my fruits engine into my cereal app. Part of that process involves copying over the routes.rb file. However, by default, that has these unfortunate routes defined already:

  map.connect ':controller/:action/:id'
  map.connect ':controller/:action/:id.:format'

Now, I hit my app at /cornflakes/new, hit the ‘Create’ button, and it posts to … my ‘index’ action?? What’s up with that? Well, it took a while, but then I remembered that default route. I’m assuming that the plugin routes get processed first, and that default route is getting installed before my resourceful route. Meaning, nothing in my app’s routes.rb file is going to get recognized. No corn flakes, no lucky charms, nothing.

Removing the offending lines set the world back to normal. Time to eat.