We all love working with Sass, but compilation can take quite a long time for larger codebases. This gem integrates the C implementation of Sass, LibSass, into the asset pipeline.

In one larger project, this made compilation 4x faster:

# Using sassc-rails
[1] pry(main)> Benchmark.bm { |bm| bm.report { Rails.application.assets["application.css"] } }
       user     system      total        real
   1.720000   0.170000   1.890000 (  1.936867)
# Using sass-rails
 [1] pry(main)> Benchmark.bm { |bm| bm.report { Rails.application.assets["application.css"] } }
       user     system      total        real
  7.820000   0.250000   8.070000 (  8.106347)

This should essentially be a drop in alternative to sass-rails.

With SassC-Rails, it's also extremely easy to turn on inline source maps. Simply add the following configuration to your development.rb file:

# config/environments/development.rb
config.sass.inline_source_maps = true

After adding this config line, you may need to clear your assets cache (rm -r tmp/cache/assets), stop spring, and restart your rails server. You may also wish to disable line comments (config.sass.line_comments = false).

Note, as indicated, these source maps are inline. They will not generate additional files or anything like that. Instead, they will be appended to the compiled application.css file.

For a look at the compatibility between Ruby Sass and LibSass, check this compatibility chart out.

Add this line to your application's Gemfile:

gem 'sassc-rails'

And then execute:

$ bundle

Due to LibSass compilation requirements, you must upgrade to the Heroku Cedar-14 Stack in order to successfully install this gem.

Upgrading to Cedar-14 is usually a painless process.

Libraries explicitly depending on Sass-Rails, such as ActiveAdmin, can cause conflicts with installation of SassC-Rails. While we have no built-in solution for this, please check out this issue for a workaround.

This gem is based on sass-rails, and is maintained by Ryan Boland and awesome contributors.

• 2.1.2
  • Correct reference to SassC::Script::Value::String
• 2.1.1
  • Fix Scaffolding
• 2.1.0
  • JRuby support
  • SCSS / SASS scaffolding
• 2.0.0
  • Drop support for Sprockets 2
  • Remove dependency on Ruby Sass
• 1.3.0
  • Silence Sprockets deprecation warnings
  • Sprockets 4 compatibility
• 1.2.1
  • Bump SassC (and thus LibSass) version
• 1.2.0
  • Support sprockets-rails 3
  • Only depend on Railties instead of full Rails
• 1.1.0
  • Moved under the official sass organization!
  • Source line comments (app.config.sass.line_comments)
  • Prevent sass-rails railtie from running
  • CSS compression may be disabled in test mode. Special thanks to this Sass-Rails PR for inspiration.
• 1.0.0
  • Initial Release
  • Add support for inline source maps
  • Support compression in the way that Sass-Rails handles it

1. Fork it ( https://github.com/sass/sassc-rails/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Add Tests
5. Push to the branch (git push origin my-new-feature)
6. Create a new Pull Request