Update sass-spec runner to support error specs

test/spec.js

@@ -44,8 +44,14 @@ describe('spec', function() {
               file: t.src,
               includePaths: t.paths
             }, function(error, result) {
+              if (t.error) {
+                assert(error);
+              } else {
                 assert(!error);
+              }
+              if (expected) {
                 assert.equal(util.normalize(result.css.toString()), expected);
+              }
               done();
             });
           });

test/util/index.js

@@ -42,6 +42,7 @@ module.exports.getSuites = function() {
 
       ret[suite][test] = {};
       ret[suite][test].src = join(testPath, 'input.scss');
+      ret[suite][test].error = fs.existsSync(join(testPath, 'error'));
       ret[suite][test].expected = join(testPath, 'expected_output.css');
       ret[suite][test].paths = [
         testPath,