You should use Browserify or Webpack to bundle code together like that. They will handle the import chains for you and give you a single file that can be passed

You should use Browserify or Webpack to bundle code together like that. They will handle the import chains for you and give you a single file that can be passed to Closure without any issues. Browserify is particularly easy to get going with; Webpack requires a bit more config. Edit: See this comment: https://news.ycombinator.com/item?id=13910621 https://news.ycombinator.com/item?id=13910621.