Rails validation for scss (or sass)

scss_format_validator.rb

# app/validators/scss_format_validator.rb
class ScssFormatValidator < ActiveModel::EachValidator
  def validate_each(object, attribute, value)
    begin
      # Attempt to parse SCSS
      Sass::Engine.new(value, syntax: :scss).render
    rescue Exception => e
      # Add error if parsing fails
      object.errors.add(attribute, :invalid_scss, error: e.inspect)
    end
  end
end

widget.rb

class Client < ActiveRecord::Base
  attr_accessible :style_text
  validates :style_text, scss_format: true
end