In addition to upgrading a few Rails apps to the latest 3.1 release candidate, we also submitted a few RailsGuides patches, found a bug and submitted a failing test. We didn't even have a chance to fix it before grzuy picked it up and submitted the patch.
We ran into a few bumps moving to the 3.1 asset pipeline, but overall the upgrade from Rails 3.0 to 3.1 has been smooth. As for the 2.3 to 3.0 upgrade, Rails provides deprecation warnings in the previous point release, 3.0.9 as I write this, so the upgrade goes a little something like this:
- Upgrade to Rails 3.0.9
- Upgrade other gems as necessary (e.g., haml 3.0 to haml 3.1 + sass 3.1)
- Run tests, fix tests, rinse and repeat
- Walk through the application and fix any deprecation warnings that crop up in the rails log
- Upgrade to Rails 3.1
And now...your moment of zen.