Recently I upgraded a project from Rails 3.2.x to 4.0.x... 4.0.x -> 4.1.x... 4.1.x -> 4.2.x It was, and still is, a nightmare. Technically speaking Rails itself upgraded in a reasonably straight-forward way, just follow the documentation (well and a few blog posts here and there for the things missed in the official docs). But all the additional Gems, and dependencies of those Gems (and so on) made the process excruc…
I have upgraded a very large Rails 3.2 app to 4.2 recently. It was about 2 weeks solid of work for my team. It was a project I inherited and when I got it the test suite took an hour to run. The biggest problem which I had was dealing with the dependencies. This project used just under 300 gems, many of them unmaintained and a few of them I had to fork to get to work with rails 3. I am very fast making things in Rail…
$ find -iname '*.rb' | xargs cat | wc -l
135106
No real problems working with this codebase. ~190 gem dependencies.Mind, most of the code is tests:
$ find -iname '*.rb' | grep /spec/ | xargs cat | wc -l
96899