Added a basic test case. So far it can be used to make sure your stylesheets compile.

Eventually it should provide assertions for generated rules and styles.

lib/compass/test_case.rb

@@ -0,0 +1,37 @@
+module Compass
+  # Write your unit test like this if you want to make sure all your stylesheets compile.
+  #
+  # require 'compass/test_case'
+  # class StylesheetsTest < Compass::TestCase
+  #   def test_stylesheets
+  #     my_sass_files.each do |sass_file|
+  #       assert_compiles(sass_file) do |result|
+  #         assert_not_blank result
+  #       end
+  #     end
+  #   end
+  #   protected
+  #   def my_sass_files
+  #     Dir.glob(File.expand_path(File.join(File.dirname(__FILE__), "../..", "app/stylesheets/**/[^_]*.sass")))
+  #   end
+  # end
+  class TestCase < Test::Unit::TestCase
+    def setup
+      @last_compile = nil
+    end
+
+    def compile(stylesheet)
+      input =  open(stylesheet)
+      template = input.read()
+      input.close()
+      @last_compile = ::Sass::Engine.new(template,
+        ::Sass::Plugin.engine_options(:style => :compact, :filename => stylesheet)).render
+      yield @last_compile if block_given?
+    end
+
+    def assert_compiles(stylesheet, &block)
+      compile(stylesheet, &block)
+    end
+
+  end
+end