liijunwei

def gems(group = nil)
  require 'bundler'

  groups = Bundler.load.current_dependencies.map {|d| d.groups }.uniq.flatten.uniq.sort
  return groups if group.nil?

  raise "unsupported gem group: #{group}" if !groups.include?(group.to_sym)

  Bundler.load.current_dependencies.select{ |dep| dep.groups.include?(group.to_sym) }
end