Episode 2 - Upgrading to Rails 3

In the first episode we moved URLAgg to Bundler as a precursor to upgrading to Rails 3.

In this episode we upgrade the project to Rails 3 and RSpec 2, get the Rails console to start, the Rails server to load and all our existing specs to run. Most specs are failing at this point, the Rails about page reports that we are running Rails 3 beta4.

These are the steps we go through on the path to upgrade:

• Create a gemset using rvm for rails 3 so we don’t clutter our system with the pre-release versions.
• Install rails dependencies for version 3 and the rails pre-release version of the gem.
• Use the rails_upgrade plugin to tell us what needs upgrading and help us back up and translate routes and configs.
• Hunt down compatible versions and branches of the gems and plugins we are using. This is by far the most time consuming part of the upgrade process.

Source code for this episode:

• Episode 2 tag in Github
• Latest HEAD for the rails3upgrade branch

References:

• The Rails 3 Upgrade Handbook is a comprehensive guide on upgrading to Rails 3
• The Rails Upgrade gem: github.com/rails/rails_upgrade
• BigSitemap plugin plugin compatible with Rails 3
• Email Spec Rails 3 compatible branch