Track Source objects in PackageNames.

lib/src/command/cache_add.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.
 
 import 'dart:async';
 
 import 'package:pub_semver/pub_semver.dart';
 
 import '../command.dart';
 import '../log.dart' as log;
@@ skipping 35 matching lines @@
     var constraint = VersionConstraint.any;
     if (argResults["version"] != null) {
       try {
         constraint = new VersionConstraint.parse(argResults["version"]);
       } on FormatException catch (error) {
         usageException(error.message);
       }
     }
 
     // TODO(rnystrom): Support installing from git too.
-    var source = cache.source("hosted");
+    var source = cache.hosted;
 
     // TODO(rnystrom): Allow specifying the server.
     var ids = (await source.getVersions(cache.sources.hosted.refFor(package)))
         .where((id) => constraint.allows(id.version))
         .toList();
 
     if (ids.isEmpty) {
       // TODO(rnystrom): Show most recent unmatching version?
       fail("Package $package has no versions that match $constraint.");
     }
@@ skipping 14 matching lines @@
       // Install them in ascending order.
       ids.sort((id1, id2) => id1.version.compareTo(id2.version));
       await Future.forEach(ids, downloadVersion);
     } else {
       // Pick the best matching version.
       ids.sort((id1, id2) => Version.prioritize(id1.version, id2.version));
       await downloadVersion(ids.last);
     }
   }
 }