Upgrading to Rails 4.0

I’m busy upgrading several apps to Rails 4.0. As is to be expected, there are a few gotchas here and there. Most are documented somewhere… deep in a changelog… mixed in with dozens of other things that probably won’t bite you.

I’ve been posting some of my notes along the journey. This particular post will serve as a central reference point, a table of contents of sorts, and will just contain links to other posts. I’ll try to keep it updated as I add new posts.

Overview

See the official Ruby on Rails article to start.

• Preparing a Rails 3.2 app to be upgraded

Models and datastores

• Using Mongoid

Assets

• Missing assets - whole directories (or gems) of assets missing
• Missing assets - problems with assets referenced by CSS files

Deployment

• Failure precompiling assets on the server
• Capistrano deployment errors