AssetHat workaround for a media query bug in the `cssmin` gem

asset_hat_extensions.rake

# rails_app/lib/tasks/asset_hat_extensions.rake
# AssetHat: http://mintdigital.github.com/asset_hat/

namespace :asset_hat_extensions do
  namespace :css do
    task :fix_media_queries do
      # The `cssmin` gem has a bug in which it shortens
      # `@media screen and (max-width:800px)` to
      # `@media screen and(max-width:800px)` -- the missing space breaks it.
      # This task re-adds the space.

      config  = AssetHat.config['css']
      bundles = config['bundles'].keys

      bundles.each do |bundle|
        bundle_filepath = AssetHat::CSS.min_filepath(
          File.join(AssetHat.bundles_dir(:css), "#{bundle}.css"))
        css = File.read(bundle_filepath)
        css.gsub!(/ and\(/, ' and (') # Caution: This regex is naive.
        File.open(bundle_filepath, 'w') { |file| file.write(css) }
      end
    end

  end # namespace :css
end # namespace :asset_hat_extensions

%w[
  asset_hat:minify
  asset_hat:minify:css
  asset_hat:css:minify
].each do |task_name|
  Rake::Task[task_name].enhance do
    Rake::Task['asset_hat_extensions:css:fix_media_queries'].invoke
  end
end