Auto-reinstall broken packages in the system cache.

utils/tests/pub/install/hosted/repair_cache_test.dart

Index: utils/tests/pub/install/hosted/repair_cache_test.dart
diff --git a/utils/tests/pub/install/hosted/install_test.dart b/utils/tests/pub/install/hosted/repair_cache_test.dart
similarity index 60%
copy from utils/tests/pub/install/hosted/install_test.dart
copy to utils/tests/pub/install/hosted/repair_cache_test.dart
index 1ed4f404e9f58878424cb6e2bb9663d3dfb45647..aca40f0b04d309ac95788bb8c90aadc9a44ceec1 100644
--- a/utils/tests/pub/install/hosted/install_test.dart
+++ b/utils/tests/pub/install/hosted/repair_cache_test.dart
@@ -4,14 +4,22 @@
 
 library pub_tests;
 
-import 'dart:io';
+import '../../../../../pkg/path/lib/path.dart' as path;
 
+import '../../../../pub/io.dart';
 import '../../test_pub.dart';
 
 main() {
-  integration('installs a package from a pub server', () {
+  initConfig();
+  integration('re-installs a package if the cached one is empty', () {
     servePackages([package("foo", "1.2.3")]);
 
+    // Make a broken empty directory in the cache.
+    schedule((sandboxDir) {
+      return hostedCacheDir("foo", "1.2.3")
+          .then((fooDir) => ensureDir(path.join(sandboxDir.path, fooDir)));
+    });

[nweiz, 2013/02/13 00:19:21]

Why aren't you using the standard directory declaration stuff here?

[Bob Nystrom, 2013/02/13 01:27:11]

The descriptor stuff is designed to represent directory trees where every node
along the path is meaningful. In this case, I just want to do something with the
leaf directory of the path.

Adding "scheduleEnsureDir()" to Descriptor felt weird to me.

+
     appDir([dependency("foo", "1.2.3")]).scheduleCreate();
 
     schedulePub(args: ['install'],