Load instances of the same transformer from the same isolate.

sdk/lib/_internal/pub/test/pubspec_test.dart

 // Copyright (c) 2012, 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 pubspec_test;
 
 import 'dart:async';
 
 import 'package:unittest/unittest.dart';
 
@@ skipping 321 matching lines @@
 
     test("allows a transformer from a normal dependency", () {
       var pubspec = new Pubspec.parse('''
 name: pkg
 dependencies:
   foo:
     mock: ok
 transformers:
 - foo''', sources);
 
-      expect(pubspec.transformers[0].single.package, equals("foo"));
+      expect(pubspec.transformers[0].single.id.package, equals("foo"));
     });
 
     test("allows a transformer from a dev dependency", () {
       var pubspec = new Pubspec.parse('''
 name: pkg
 dev_dependencies:
   foo:
     mock: ok
 transformers:
 - foo''', sources);
 
-      expect(pubspec.transformers[0].single.package, equals("foo"));
+      expect(pubspec.transformers[0].single.id.package, equals("foo"));
     });
 
     test("allows a transformer from a dependency override", () {
       var pubspec = new Pubspec.parse('''
 name: pkg
 dependency_overrides:
   foo:
     mock: ok
 transformers:
 - foo''', sources);
 
-      expect(pubspec.transformers[0].single.package, equals("foo"));
+      expect(pubspec.transformers[0].single.id.package, equals("foo"));
     });
 
     test("allows comment-only files", () {
       var pubspec = new Pubspec.parse('''
 # No external dependencies yet
 # Including for completeness
 # ...and hoping the spec expands to include details about author, version, etc
 # See http://www.dartlang.org/docs/pub-package-manager/ for details
 ''', sources);
       expect(pubspec.version, equals(Version.none));
@@ skipping 34 matching lines @@
             (pubspec) => pubspec.environment);
       });
 
       test("throws if the sdk isn't a valid version constraint", () {
         expectPubspecException('environment: {sdk: "oopies"}',
             (pubspec) => pubspec.environment);
       });
     });
   });
 }