Track Source objects in PackageNames.

test/lock_file_test.dart

Index: test/lock_file_test.dart
diff --git a/test/lock_file_test.dart b/test/lock_file_test.dart
index c59202e4424ac9b77aa699a0fb4ed30749e65123..ca6e0836156129bd064c675ad6e026b0349ff753 100644
--- a/test/lock_file_test.dart
+++ b/test/lock_file_test.dart
@@ -19,17 +19,19 @@ class MockSource extends Source {
 
   PackageRef parseRef(String name, description, {String containingPath}) {
     if (!description.endsWith(' desc')) throw new FormatException('Bad');
-    return new PackageRef(name, this.name, description);
+    return new PackageRef(name, this, description);
   }
 
   PackageId parseId(String name, Version version, description) {
     if (!description.endsWith(' desc')) throw new FormatException('Bad');
-    return new PackageId(name, this.name, version, description);
+    return new PackageId(name, this, version, description);
   }
 
   bool descriptionsEqual(description1, description2) =>
       description1 == description2;
 
+  int hashDescription(description) => description.hashCode;
+
   String packageName(String description) {
     // Strip off ' desc'.
     return description.substring(0, description.length - 5);
@@ -71,13 +73,13 @@ packages:
         var bar = lockFile.packages['bar'];
         expect(bar.name, equals('bar'));
         expect(bar.version, equals(new Version(1, 2, 3)));
-        expect(bar.source, equals(mockSource.name));
+        expect(bar.source, equals(mockSource));
         expect(bar.description, equals('bar desc'));
 
         var foo = lockFile.packages['foo'];
         expect(foo.name, equals('foo'));
         expect(foo.version, equals(new Version(2, 3, 4)));
-        expect(foo.source, equals(mockSource.name));
+        expect(foo.source, equals(mockSource));
         expect(foo.description, equals('foo desc'));
       });
 
@@ -90,7 +92,7 @@ packages:
     description: foo desc
 ''', sources);
         var foo = lockFile.packages['foo'];
-        expect(foo.source, equals('bad'));
+        expect(foo.source, equals(sources['bad']));
       });
 
       test("allows an empty dependency map", () {
@@ -190,10 +192,9 @@ packages:
     test('serialize() dumps the lockfile to YAML', () {
       var lockfile = new LockFile([
         new PackageId(
-          'foo', mockSource.name, new Version.parse('1.2.3'), 'foo desc'),
-        new PackageId(
-          'bar', mockSource.name, new Version.parse('3.2.1'), 'bar desc')
-      ], sources);
+          'foo', mockSource, new Version.parse('1.2.3'), 'foo desc'),
+        new PackageId('bar', mockSource, new Version.parse('3.2.1'), 'bar desc')
+      ]);
 
       expect(loadYaml(lockfile.serialize(null)), equals({
         'sdk': 'any',