module Bundler

def gem_setup(*groups)
  return @setup if @setup
  begin
    if groups.empty?
      # Load all groups, but only once
      @setup = load.setup
    else
      # Figure out which groups haven't been loaded yet
      unloaded = groups - (@completed_groups || [])
      # Record groups that are now loaded
      @completed_groups = groups | (@completed_groups || [])
      # Load any groups that are not yet loaded
      unloaded.any? ? load.setup(*unloaded) : load
    end
  rescue Bundler::GemNotFound => e
    STDERR.puts e.message
    STDERR.puts "Try running `bundle install`."
    exit!
  end
end