Upgrading Rails 2.x to Rails 3

I gathered a small collection of sites on how to upgrade from Rails 2.x to Rails 3 for my last job. But we never got around to using it. But instead of throwing away the bookmarks, I thought it might be a good idea to save them somewhere more “permanent”.

One method I keep hearing from others who have done it is to make sure you have decent test coverage for your app. And then upgrade one baby steps at a time: First upgrade to the next immediate major version of Rails, and then the one after that… etc. For example, Rails 2.3.x => 3.0, and then 3.0 => 3.1, and then 3.1 => 3.2… etc. And along the way, fix your code and make sure all the tests pass.

Happy coding.