Rails config.assets.precompile setting to process all CSS and JS files in app/assets

config.assets.precompile = ['*.js', '*.css']

That will compile any JavaScript or CSS in your asset path, regardless of directory depth. Found via this answer.

This task is made more difficult by the fact that sprockets works with logical paths that do not include where the underlying, uncompiled resourced is located.

Suppose my project has the JS file "/app/assets/javascripts/foo/bar.js.coffee".

The sprockets compiler will first determine the output file extension, in this case ".js", and then the evaluate whether or not to compile the logical path "foo/bar.js". The uncompiled resource could be in "app/assets/javascripts", "vendor/assets/javascripts", "lib/assets/javascripts" or a gem, so there is no way to include/exclude a particular file based on the logical path alone.

To determine where the underlying resource is located, I believe it is necessary to ask the sprockets environment (available via the object Rails.application.assets) to resolve the real path of the resource given the logical path.

Here is the solution that I am using. I am fairly new to Ruby so this is not the most elegant code:

# In production.rbconfig.assets.precompile << Proc.new { |path|  if path =~ /\.(css|js)\z/    full_path = Rails.application.assets.resolve(path).to_path    app_assets_path = Rails.root.join('app', 'assets').to_path    if full_path.starts_with? app_assets_path      puts "including asset: " + full_path      true    else      puts "excluding asset: " + full_path      false    end  else    false  end}

With sprockets > 3.0, this will not work in production because Rails.application.assets will be nil (assuming default: config.assets.compile = false).

To workaround you replace the full_path assignment with:

@assets ||= Rails.application.assets || Sprockets::Railtie.build_environment(Rails.application)full_path = @assets.resolve(path)

See also: https://github.com/rails/sprockets-rails/issues/237

A slight tweak to techpeace's answer:

config.assets.precompile = ['*.js', '*.css', '**/*.js', '**/*.css']

I would've added a comment to his answer but I don't have enough reputation yet. Give me an upvote and I'll be there!

NOTE: this will also precompile all the CSS/JavaScript included via rubygems.