You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: spec_helper.rb
    path of file: ./repos/jekyll-auth/spec
    
    the code of the file until where you have to start completion: # frozen_string_li
    
def setup_tmp_dir
  tear_down_tmp_dir
  FileUtils.mkdir tmp_dir
  File.write File.expand_path("index.html", tmp_dir), "My awesome site"
  FileUtils.mkdir "#{tmp_dir}/some_dir"
  File.write File.expand_path("some_dir/index.html", tmp_dir), "My awesome directory"
  Dir.chdir tmp_dir
end