Upgrading rails project - version 1.2.6 to current (2.3.5)

Can anyone please advise me what is involved in up grading a project
from version 1.2.6 to current (2.3.5). The project is pretty much
vanilla code and does not use plugins. Are there scripts that can do
the job (or pull out incompatibilities). Any websites or blogs that
point the way or should I just bite the bullet and rewrite? Reason for
wanting to upgrade is that I now do want to add features and start
using plugins and of cause a lot of the plugins that I would like to
use require rails 2.3+


Paul Thompson.

First, I'd recommend doing this in steps, first upgrade to Rails 2.0,
then 2.1, then 2.3.5

Why? Rails 1.x to 2.0 was a pretty big change, for some apps 2.0 to
2.1 was even bigger because of some subtle and significant changes to

So I'd do each step, and pause to make sure your tests are working.
You DO have tests don't you?

Googling for rails upgrade, flushed out this article on the first
step, more specific searches are likely to find articles on the


It includes a pointer to a rake task written by Geoffrey Grossenbach
(of Peepcode fame) which find stuff deprecated in 2.0.

Recent versions of Rails have rake tasks to aid in upgrading e.g. in 2.3.5

rake rails:update # Update both
configs, scripts and public/javascripts from Rails
rake rails:update:application_controller # Rename
application.rb to application_controller.rb
rake rails:update:configs # Update
config/boot.rb from your current rails install
rake rails:update:generate_dispatchers # Generate
dispatcher files in RAILS_ROOT/public
rake rails:update:javascripts # Update your
javascripts from your current rails install
rake rails:update:scripts # Add new
scripts to the application script/ directory

I don't recall if 2.0 had these, or at what point they were introduced.