Updating code_transformer's ResolverTransform to filter on Dart entry points in apply.

pkg/code_transformers/test/resolver_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.resolver_test;
 
 import 'dart:async';
 
 import 'package:barback/barback.dart';
 import 'package:code_transformers/resolver.dart';
 import 'package:code_transformers/tests.dart';
 import 'package:unittest/compact_vm_config.dart';
 import 'package:unittest/unittest.dart';
 
 main() {
   useCompactVMConfiguration();
   var entryPoint = new AssetId('a', 'web/main.dart');
   var resolvers = new Resolvers(testingDartSdkDirectory);
 
   Future validateResolver({Map<String, String> inputs, validator(Resolver),
       List<String> messages: const[]}) {
     return applyTransformers(
           [[new TestTransformer(resolvers, entryPoint, validator)]],
           inputs: inputs,
           messages: messages);
   }
 
   group('Resolver', () {
 
-    test('should handle empty files', () {
+    test('should handle initial files', () {
       return validateResolver(
           inputs: {
-            'a|web/main.dart': '',
+            'a|web/main.dart': ' main() {}',
           },
           validator: (resolver) {
             var source = resolver.sources[entryPoint];
             expect(source.modificationStamp, 1);
 
             var lib = resolver.getLibrary(entryPoint);
             expect(lib, isNotNull);
-            expect(lib.entryPoint, isNull);
           });
     });
 
     test('should update when sources change', () {
       return validateResolver(
           inputs: {
-            'a|web/main.dart': ''' main() {} ''',
+            'a|web/main.dart': ''' main() {
+                } ''',
           },
           validator: (resolver) {
             var source = resolver.sources[entryPoint];
             expect(source.modificationStamp, 2);
 
             var lib = resolver.getLibrary(entryPoint);
             expect(lib, isNotNull);
             expect(lib.entryPoint, isNotNull);
           });
     });
@@ skipping 297 matching lines @@
 
   // TODO(nweiz): This should just take an AssetId when barback <0.13.0 support
   // is dropped.
   Future<bool> isPrimary(idOrAsset) {
     var id = idOrAsset is AssetId ? idOrAsset : idOrAsset.id;
     return new Future.value(id == primary);
   }
 
   applyResolver(Transform transform, Resolver resolver) => validator(resolver);
 }