A ruby class for analyzing the dependencies in a sass file.

dependency_extractor.rb

# extracts dependencies for a file
class DependencyExtractor
  class Asset < Struct.new(:filename, :importer, :children)
    def initialize(*args)
      super
      self.children ||= []
    end

    # transitive dependencies. Call `children` for just the immediate dependencies.
    def dependencies
      children.map {|child| [child, child.dependencies] }.flatten
    end
  end

  include Sass::Plugin

  def initialize(options = {})
    @options = Sass::Engine.normalize_options(options)
  end

  def analyze(*files)
    files.map {|f| analyze_file(f) }
  end

  def analyze_file(f, importer = importer)
    children = checker.send(:dependencies, f, importer).map{|c| analyze_file(*c) }
    Asset.new(f, importer, children)
  end

  def importer
    @importer ||= @options[:filesystem_importer].new(".")
  end

  def checker
    @checker ||= StalenessChecker.new(@options)
  end
end