Fixed a bug in the configuration parser.

Added Compass#sass_engine_options method to emit sass options suitable
for passing to Sass::Engine#new.

Added require tracking in the configuration parser and serializer.

lib/compass/configuration.rb

@@ -3,25 +3,54 @@ require 'singleton'
 module Compass
   class Configuration
     include Singleton
-    attr_accessor :project_path, :css_dir, :sass_dir, :images_dir, :javascripts_dir
+    attr_accessor :project_path, :css_dir, :sass_dir, :images_dir, :javascripts_dir, :required_libraries
+
+    def initialize
+      self.required_libraries = []
+    end
 
     # parses a manifest file which is a ruby script
     # evaluated in a Manifest instance context
     def parse(config_file)
       open(config_file) do |f|
-        eval(f.read, instance_binding, config_file)
+        parse_string(f.read, config_file)
       end
     end
 
+    def parse_string(contents, filename)
+      eval(contents, binding, filename)
+      [:css_dir, :sass_dir, :images_dir, :javascripts_dir].each do |prop|
+        value = eval(prop.to_s, binding) rescue nil
+        self.send("#{prop}=", value) if value
+      end
+    end
+
+    def serialize
+      contents = ""
+      required_libraries.each do |lib|
+        contents << %Q{require '#{lib}'\n}
+      end
+      contents << "\n" if required_libraries.any?
+      [:css_dir, :sass_dir, :images_dir, :javascripts_dir].each do |prop|
+        value = send(prop)
+        contents << %Q(#{prop} = "#{value}"\n) if value
+      end
+      contents
+    end
+
+    # Support for testing.
     def reset!
       [:project_path, :css_dir, :sass_dir, :images_dir, :javascripts_dir].each do |attr|
         send("#{attr}=", nil)
       end
+      self.required_libraries = []
     end
 
-    def instance_binding
-      binding
+    def require(lib)
+      required_libraries << lib
+      super
     end
+
   end
 
   module ConfigHelpers
@@ -45,6 +74,17 @@ module Compass
     def configure_sass_plugin!
       Sass::Plugin.options.merge!(sass_plugin_configuration)
     end
+
+    def sass_engine_options
+      load_paths = []
+      if configuration.project_path && configuration.sass_dir
+        load_paths << File.join(configuration.project_path, configuration.sass_dir)
+      end
+      Compass::Frameworks::ALL.each do |framework|
+        load_paths << framework.stylesheets_directory
+      end
+      {:load_paths => load_paths}
+    end
   end
 
   extend ConfigHelpers

test/configuration_test.rb

@@ -0,0 +1,28 @@
+require  File.dirname(__FILE__)+'/test_helper'
+require 'compass'
+
+class ConfigurationTest < Test::Unit::TestCase
+  def test_parse_and_serialize
+    contents = <<-CONFIG
+      require 'compass'
+      require 'sass'
+
+      css_dir = "css"
+      sass_dir = "sass"
+      images_dir = "img"
+      javascripts_dir = "js"
+    CONFIG
+
+    Compass.configuration.parse_string(contents, "test_parse")
+
+    assert_equal 'sass', Compass.configuration.sass_dir
+    assert_equal 'css', Compass.configuration.css_dir
+    assert_equal 'img', Compass.configuration.images_dir
+    assert_equal 'js', Compass.configuration.javascripts_dir
+
+    expected_lines = contents.split("\n").map{|l|l.strip}
+    actual_lines = Compass.configuration.serialize.split("\n").map{|l|l.strip}
+    assert_equal expected_lines, actual_lines
+  end
+
+end