# File lib/rubygems/test_utilities.rb, line 70
  def download spec, source_uri, install_dir = Gem.dir
    name = "#{spec.full_name}.gem"
    path = File.join(install_dir, 'cache', name)

    Gem.ensure_gem_subdirectories install_dir

    if source_uri =~ /^http/ then
      File.open(path, "wb") do |f|
        f.write fetch_path(File.join(source_uri, "gems", name))
      end
    else
      FileUtils.cp source_uri, path
    end

    path
  end