collect config.gem dependencies from capistrano, or anywhere

=begin
http://groups.google.com/group/capistrano/msg/9f17c9c7787ac390

Message from discussion deploy:check and config.gem
From: Tom Copeland <[email protected]>
Date: Thu, 4 Feb 2010 06:57:50 -0500
Local: Thurs, Feb 4 2010 3:57 am
Subject: Re: [capistrano] deploy:check and config.gem

On Feb 4, 2010, at 6:39 AM, Tom Copeland wrote:

> Hi all -

> I saw some discussion of this in the archives, but has anyone done integration between deploy:check and config.gem?  I know there are tricky bits - e.g., config/environments/foo.rb could declare its own dependencies - but maybe just something for the simple case of all dependencies being declared in config/environment.rb?

Maybe (paste this in your in deploy.rb):
=end

class Collecter
  attr_accessor :dependencies
  def initialize
    @dependencies = {}
    File.read("config/environment.rb").split("\n").collect {|line| line.strip }.select {|line| line[0] != '#' }.select {|line| line.match(/^config.gem/) }.each do |line|
      self.instance_eval(line)
    end
  end
  def gem(name, args)
    @dependencies[name] = args
    args[:version] = ">=0.0.1" unless args.include?(:version)
  end
  def config
    self
  end
end

Collecter.new.dependencies.each do |name, args|
  depend :remote, :gem, name, args[:version]
end