Updating code_transformers to not fail on syntax errors

pkg/code_transformers/test/entry_point_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library code_transformers.test.assets_test;
 
 import 'dart:async';
 import 'dart:io' show File, Platform;
 
 import 'package:barback/barback.dart';
@@ skipping 58 matching lines @@
           expectation: true);
     });
 
     test('should count parts as main', () {
       return checkDartEntry(
           inputs: {
             'a|web/main.dart': 'part "foo.dart";',
           },
           expectation: true);
     });
+
+    test('is tolerant of syntax errors with main', () {
+      return checkDartEntry(
+          inputs: {
+            'a|web/main.dart': 'main() {} {',
+          },
+          expectation: true);
+    });
+
+    test('is tolerant of syntax errors without main', () {
+      return checkDartEntry(
+          inputs: {
+            'a|web/main.dart': 'class Foo {',
+          },
+          expectation: false);
+    });
   });
 }
 
 class Validator extends Transformer {
   final Function validation;
 
   Validator(this.validation);
 
   Future<bool> isPrimary(Asset input) => new Future.value(true);
 
   Future apply(Transform transform) {
     return new Future.value(validation(transform));
   }
 }