Make pub strong-mode clean.

lib/src/source/git.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.
 
 import 'dart:async';
 
 import 'package:path/path.dart' as path;
 import 'package:pub_semver/pub_semver.dart';
 
 import '../git.dart' as git;
@@ skipping 138 matching lines @@
   BoundGitSource(this.source, this.systemCache);
 
   /// The paths to the canonical clones of repositories for which "git fetch"
   /// has already been run during this run of pub.
   final _updatedRepos = new Set<String>();
 
   /// Given a Git repo that contains a pub package, gets the name of the pub
   /// package.
   Future<String> getPackageNameFromRepo(String repo) {
     // Clone the repo to a temp directory.
-    return withTempDir((tempDir) {
-      return _clone(repo, tempDir, shallow: true).then((_) {
-        var pubspec = new Pubspec.load(tempDir, systemCache.sources);
-        return pubspec.name;
-      });
+    return withTempDir((tempDir) async {
+      await _clone(repo, tempDir, shallow: true);
+      var pubspec = new Pubspec.load(tempDir, systemCache.sources);
+      return pubspec.name;
     });
   }
 
   Future<List<PackageId>> doGetVersions(PackageRef ref) async {
     await _ensureRepoCache(ref);
     var path = _repoCachePath(ref);
     var revision = await _firstRevision(path, ref.description['ref']);
     var pubspec = await _describeUncached(ref, revision);
 
     return [
@@ skipping 68 matching lines @@
     // TODO(keertip): Implement getCachedPackages().
     throw new UnimplementedError(
         "The git source doesn't support listing its cached packages yet.");
   }
 
   /// Resets all cached packages back to the pristine state of the Git
   /// repository at the revision they are pinned to.
   Future<Pair<List<PackageId>, List<PackageId>>> repairCachedPackages() async {
     if (!dirExists(systemCacheRoot)) return new Pair([], []);
 
-    var successes = [];
-    var failures = [];
+    var successes = <PackageId>[];
+    var failures = <PackageId>[];
 
     var packages = listDir(systemCacheRoot)
         .where((entry) => dirExists(path.join(entry, ".git")))
         .map((packageDir) => new Package.load(
             null, packageDir, systemCache.sources))
         .toList();
 
     // Note that there may be multiple packages with the same name and version
     // (pinned to different commits). The sort order of those is unspecified.
     packages.sort(Package.orderByNameAndVersion);
@@ skipping 118 matching lines @@
         (result) => null);
   }
 
   /// Returns the path to the canonical clone of the repository referred to by
   /// [id] (the one in `<system cache>/git/cache`).
   String _repoCachePath(PackageRef ref) {
     var repoCacheName = '${ref.name}-${sha1(ref.description['url'])}';
     return path.join(systemCacheRoot, 'cache', repoCacheName);
   }
 }