fast fail update-packages

packages/flutter_tools/lib/src/commands/update_packages.dart

@@ -10,14 +10,15 @@ import '../dart/pub.dart';
 import '../globals.dart';
 import '../runner/flutter_command.dart';
 
+/// Return the total number of projects run; throws the exit code on error.
 Future<int> _runPub(Directory directory, { bool upgrade: false }) async {
   int updateCount = 0;
   for (FileSystemEntity dir in directory.listSync()) {
     if (dir is Directory && FileSystemEntity.isFileSync(dir.path + Platform.pathSeparator + 'pubspec.yaml')) {
       updateCount++;
-      // TODO(eseidel): Should this fail immediately if pubGet fails?
-      // Currently we're ignoring the return code.
-      await pubGet(directory: dir.path, upgrade: upgrade, checkLastModified: false);
+      int code = await pubGet(directory: dir.path, upgrade: upgrade, checkLastModified: false);
+      if (code != 0)
+        throw code;
     }
   }
   return updateCount;
@@ -46,13 +47,20 @@ class UpdatePackagesCommand extends FlutterCommand {
 
   @override
   Future<int> runInProject() async {
+    try {
       Stopwatch timer = new Stopwatch()..start();
       int count = 0;
       bool upgrade = argResults['upgrade'];
+
       count += await _runPub(new Directory("${ArtifactStore.flutterRoot}/packages"), upgrade: upgrade);
       count += await _runPub(new Directory("${ArtifactStore.flutterRoot}/examples"), upgrade: upgrade);
       count += await _runPub(new Directory("${ArtifactStore.flutterRoot}/dev"), upgrade: upgrade);
+
       printStatus('Ran "pub" $count time${count == 1 ? "" : "s"} in ${timer.elapsedMilliseconds} ms');
+
       return 0;
+    } on int catch (code) {
+      return code;
+    }
   }
 }