Upgrading to Rails 3

February 27th, 2011

Introduction

It was long overdue.

Rails 3.0.5 is out and I’ve finally bitten the bullet and upgraded this site to Rails 3 and Ruby 1.9.2. The site had its genesis back in mid-2007 as I was preparing to start my own business. Since 2008 the codebase hasn’t received much love. Indeed, I have only published articles here in dribs and drabs over the last couple of years.

So, as I embarked on this upgrade, I was aware that it also represented an opportunity to clean up some of my code as well as update third party libraries.

What follows is a story of how the upgrade unfolded including some decisions I made along the way and some lessons I learned.

Ruby 1.9.2

My initial intention was to just upgrade the app to use Ruby 1.9.2 and attack the Rails 3 upgrade later. However, as I soon found out, getting the app to work on Ruby 1.9 wasn’t as easy as I had anticipated. Sure, using RVM it was easy to change to using Ruby 1.9.2 in development. I also chose to move to Bundler even though my intention was to stay at Rails 2.3 for now.

However, I quickly discovered that not all the plugins I was using had been upgraded to run on Ruby 1.9.

Syntax Highlighting Adventures

Back in 2008 when I implemented syntax code highlighting I chose to use the tm_syntax_highlighting plugin, which is based on Ultraviolet. Unfortunately, the original tm_syntax_highlighting plugin is not supported on Ruby 1.9. There is a gem derived from it that claims to support Ruby 1.9 but I failed to get this to work.

I had a look at the suggestions from Ryan Bates and, because I had been using a solution based on Ultraviolet, I considered using Harsh but soon found that it was not supported on Ruby 1.9.

At this point I decided to go the whole hog and upgrade to Rails 3. As for supporting syntax highlighting, I ended up switching to use CodeRay.

Rails 3 Here I Come

First point of call for anybody embarking on a Rails 3 upgrade has to be Jeremy McAnally’s Rails 3 Upgrade Handbook. This invaluable resource not only guides you through using the official “rails upgrade” tool but explains how to make the most of the improvements in Rails 3.

So I methodically worked my way through the upgrade to the point where I was able to start and use the Rails console. This was a real milestone but I still had much to do before I could consider my upgrade complete.

Time to jettison old plugins

When I attempted to get the app running via a browser it quickly became evident that it was high time I jettisoned some ancient plugins.

Chief of these was the acts_as_authenticated plugin. Yes, I did say ancient. I’m aware that Devise is a favoured authentication solution for Rails 3. However, having had success in other projects with Authlogic, I chose to use it in the interests of expediency.

Another old plugin that needed replacing was acts_as_taggable_on_steroids. The acts_as_taggable_on gem proved to be an effective replacement for this with minimal changes required.

The final old plugin to be jettisoned was akismetor, which I replaced with the Rakismet gem.

Some comments about testing

I haven’t said anything about automated tests to this point. That is quite simply because I haven’t touched them. I know I should but, since this is a relatively small app that really only affects me, I decided to bypass automated testing in favour of completing the upgrade quickly. Some may scold me for this decision but I couldn’t justify the effort to myself. I’ll come back and get the automated tests working again later.

Note: If this was a larger app for a customer I would be far less inclined to bypass the task of ensuring that the automated tests work before considering the upgrade complete.

Reflections

I’m glad I’ve taken the time to upgrade this app to Rails 3 and Ruby 1.9.2. It has given me the chance to:

  • replace old plugins with more recent gems;
  • take advantage of Bundler;
  • practice upgrading to Rails 3;
  • position the app for further code improvements courtesy of Rails 3 and Ruby 1.9.

And, of course, now I can say that I have upgraded an old Rails app to Rails 3!

Tags: rails ruby

Comments

And only now, embarrassingly, have I fixed the problem that was preventing people from posting comments. I think.

Posted by: Keith Pitty about 2 months later

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