ruby - Forking a gem for a Rails project

Question

I've found myself twice in this situation: I install a gem on my system and start using it from my Rails project. Eventually I need to make some changes to that gem. How should I proceed?

Ideally I'd like to check out the source code of that gem somewhere, like ~/third_party/gems, work on it and have my Rails project use that instead. Is that possible?

In all the cases the gems were at github so I would probably for it at github, clone it, make my chances and maintain my own branch. I suppose then I would install that branch directly with gem install on my server. Does that make sense?

Answer 1

Today this is pretty easy to do with Bundler. You make a local copy of the gem and then instead of doing

gem "whatever"

in your Gemfile, you do:

gem "whatever", :path => "/home/pupeno/whatever"

After running bundle install, the gem is picked from that directory. Even if you modify something in there, all you need to do to re-load it is restart Rails.

If you need to deploy an application using your own changes of a Gem, you make a fork, on Github or similar and on the Gemfile you do:

gem "whatever", :git => "git@github.com:/pupeno/whatever.git"

and that's it. It's simple, straightforward and beautiful.