Clean up the semantics of package descriptions.

test/version_solver_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 pub_upgrade_test;
 
 import 'dart:async';
 
 import 'package:pub/src/lock_file.dart';
 import 'package:pub/src/log.dart' as log;
@@ skipping 1369 matching lines @@
   /// Keeps track of which package pubspecs have been requested. Ensures that a
   /// source is only hit once for a given package and that pub internally
   /// caches the results.
   final _requestedPubspecs = new Map<String, Set<Version>>();
 
   final String name;
   final hasMultipleVersions = true;
 
   MockSource(this.name);
 
-  dynamic parseDescription(String containingPath, description,
-                             {bool fromLockFile: false}) => description;
+  PackageRef parseRef(String name, description, {String containingPath}) =>
+      new PackageRef(name, this.name, description);
+
+  PackageId parseId(String name, Version version, description) =>
+      new PackageId(name, this.name, version, description);
 
   bool descriptionsEqual(description1, description2) =>
       description1 == description2;
 
   String getDirectory(PackageId id) => '${id.name}-${id.version}';
 
   Future<List<PackageId>> doGetVersions(PackageRef ref) async {
     // Make sure the solver doesn't request the same thing twice.
     if (_requestedVersions.contains(ref.description)) {
-      throw new Exception('Version list for $description was already '
+      throw new Exception('Version list for ${ref.description} was already '
           'requested.');
     }
 
     _requestedVersions.add(ref.description);
 
     if (!_packages.containsKey(ref.description)){
       throw new Exception('MockSource does not have a package matching '
           '"${ref.description}".');
     }
 
-    return _packages[ref.description].values
-        .map((package) => ref.atVersion(package.version)).toList();
+    return _packages[ref.description].values.map((package) {
+      return new PackageId(
+          ref.name, this.name, package.version, ref.description);
+    }).toList();
   }
 
   Future<Pubspec> describeUncached(PackageId id) {
     return new Future.sync(() {
       // Make sure the solver doesn't request the same thing twice.
       if (_requestedPubspecs.containsKey(id.description) &&
           _requestedPubspecs[id.description].contains(id.version)) {
         throw new Exception('Pubspec for $id was already requested.');
       }
 
@@ skipping 105 matching lines @@
   }
 
   var source = "mock1";
   if (match[7] != null) {
     source = match[7];
     if (source == "root") source = null;
   }
 
   return new PackageId(name, source, parsedVersion, description);
 }