Official Ruby-on-Rails Integration with Sass

This gem provides official integration for ruby on rails projects with the Sass stylesheet language.


Since rails 3.1, new rails projects will be already configured to use Sass. If you are upgrading to rails 3.1 you will need to add the following to your Gemfile:

gem 'sass-rails'


To configure Sass via rails set use config.sass in your application and/or environment files to set configuration properties that will be passed to Sass.


MyProject::Application.configure do
  config.sass.line_comments = false
  config.sass.syntax = :nested


The list of supported options can be found on the Sass Website with the following caveats:

  1. Output compression is now controlled via the config.assets.compress boolean option instead of through the :style option.
  2. :never_update - This option is not supported. Instead set config.assets.enabled = false
  3. :always_update - This option is not supported. Sprockets uses a controller to access stylesheets in development mode instead of a full scan for changed files.
  4. :always_check - This option is not supported. Sprockets always checks in development.
  5. :syntax - This is determined by the file's extensions.
  6. :filename - This is determined by the file's name.
  7. :line - This is provided by the template handler.


  • Glob Imports. When in rails, there is a special import syntax that allows you to glob imports relative to the folder of the stylesheet that is doing the importing. E.g. @import "mixins/*" will import all the files in the mixins folder and @import "mixins/**/*" will import all the files in the mixins tree. Any valid ruby glob may be used. The imports are sorted alphabetically. NOTE: It is recommended that you only use this when importing pure library files (containing mixins and variables) because it is difficult to control the cascade ordering for imports that contain styles using this approach.

  • Asset Helpers. When using the asset pipeline, paths to assets must be rewritten. When referencing assets use the following asset helpers:

    • asset_path($relative-asset-path, $asset-class) - Returns a string to the asset. For example: asset_path("rails.png", image) becomes "/assets/rails.png"
    • asset_url($relative-asset-path, $asset-class) - Returns url reference to the asset.

    For example: asset_url("rails.png", image) becomes url(/assets/rails.png)

    • As a convenience, for each of the following asset classes there are corresponding _path and _url helpers: image, font, video, audio, javascript, stylesheet.

    For example: image_url("rails.png") becomes url(/assets/rails.png) and image_path("rails.png") becomes "/assets/rails.png".

Running Tests

$ bundle install
$ bundle exec rake test

If you need to test against local gems, use Bundler's gem :path option in the Gemfile and also edit test/support/test_helper.rb and tell the tests where the gem is checked out.