Rails migration from 2.3.4 to 3.1

I have a RoR app running over Rails 2.3.4 and ruby 1.8.6 … I am
planning to migrate to Rails 3.1

What or how will be the best way to do it? is there any application that
could help us to do this migration?


This episode on railscasts.com describes exactly what you’re looking


Hope this helps!

2012/1/4 Jesus G. [email protected]

Hi Jesus,

Here are the 4 RailsCasts on this topic, these will get you started:

  1. http://railscasts.com/episodes/225-upgrading-to-rails-3-part-1 - This
    screencast shows how to use rails_upgrade plugin to check the required
    changes and update your configuration to Rails 3, along with
    on how to update some of the popular Gems.

  2. http://railscasts.com/episodes/226-upgrading-to-rails-3-part-2 - This
    screencast shows how to update your test suite, run the app and fix any
    errors introduced due to backwards incompatible changes introduced in

  3. http://railscasts.com/episodes/227-upgrading-to-rails-3-part-3 - This
    screencast shows how to update all your views to match the new syntax
    Rails 3 and remove any deprecation warnings, so that upgrade to future
    Rails versions is easier.

  4. http://railscasts.com/episodes/282-upgrading-to-rails-3-1 - This
    screencast shows how to upgrade to Rails 3.1 from Rails 3.0 and take
    advantage of the new asset pipeline introduced in Rails 3.1

In a nut-shell, key things that will help are rails_upgrade plugin,
all your gems and plugins to a Rails 3 compatible version or find a
replacement for them which is Rails 3 compatible, run your test suite to
check for any failures, if you don’t have one, then create a simple test
suite for your app using capybara which tests key features of your app
then upgrade to Rails 3.

I am writing a set of articles for a step-by-step upgrade to Rails 3.x,
will link to them when they are ready, but in the meantime, feel free to
send across any questions if you get stuck anywhere during the upgrade


On Thu, Jan 5, 2012 at 12:10 AM, Benjamin Iandavid R. <