14km

Embedding IRB into your Ruby application

I needed to play around with Capybara/Selenium, but it’s a pain waiting for Firefox to start up every time you make a small change. Fortunately, I’m not the only one with the problem. Drop this somewhere:

require 'irb'

module IRB # :nodoc:
  def self.start_session(binding)
    unless @__initialized
      args = ARGV
      ARGV.replace(ARGV.dup)
      IRB.setup(nil)
      ARGV.replace(args)
      @__initialized = true
    end

    workspace = WorkSpace.new(binding)

    irb = Irb.new(workspace)

    @CONF[:IRB_RC].call(irb.context) if @CONF[:IRB_RC]
    @CONF[:MAIN_CONTEXT] = irb.context

    catch(:IRB_EXIT) do
      irb.eval_input
    end
  end
end 

And it’s use is quite simple. When you want to drop into an irb session, you simply do

IRB.start_session(binding)