class Gem::TestCase

def save_gemspec name = 'a', version = 1, directory = '.'
  vendor_spec = Gem::Specification.new name, version do |specification|
    yield specification if block_given?
  end
  open File.join(directory, "#{name}.gemspec"), 'w' do |io|
    io.write vendor_spec.to_ruby
  end
  return name, vendor_spec.version, directory
end