Use a bare git repository for the repo cache.

utils/tests/pub/pub_install_git_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_tests');
 
 #import('dart:io');
 
 #import('test_pub.dart');
 #import('../../../pkg/unittest/unittest.dart');
 
 main() {
   test('checks out a package from Git', () {
     ensureGit();
 
     git('foo.git', [
       file('foo.dart', 'main() => "foo";')
     ]).scheduleCreate();
 
     appDir([{"git": "../foo.git"}]).scheduleCreate();
 
     schedulePub(args: ['install'],
         output: const RegExp(@"Dependencies installed!$"));
 
     dir(cachePath, [
       dir('git', [
-        dir('cache', [gitPackageCacheDir('foo')]),
-        gitPackageCacheDir('foo')
+        dir('cache', [gitPackageRepoCacheDir('foo')]),
+        gitPackageRevisionCacheDir('foo')
       ])
     ]).scheduleValidate();
 
     dir(packagesPath, [
       dir('foo', [
         file('foo.dart', 'main() => "foo";')
       ])
     ]).scheduleValidate();
 
     run();
@@ skipping 12 matching lines @@
     ]).scheduleCreate();
 
     appDir([{"git": "../foo.git"}]).scheduleCreate();
 
     schedulePub(args: ['install'],
         output: const RegExp("Dependencies installed!\$"));
 
     dir(cachePath, [
       dir('git', [
         dir('cache', [
-          gitPackageCacheDir('foo'),
-          gitPackageCacheDir('bar')
+          gitPackageRepoCacheDir('foo'),
+          gitPackageRepoCacheDir('bar')
         ]),
-        gitPackageCacheDir('foo'),
-        gitPackageCacheDir('bar')
+        gitPackageRevisionCacheDir('foo'),
+        gitPackageRevisionCacheDir('bar')
       ])
     ]).scheduleValidate();
 
     dir(packagesPath, [
       dir('foo', [
         file('foo.dart', 'main() => "foo";')
       ]),
       dir('bar', [
         file('bar.dart', 'main() => "bar";')
       ])
@@ skipping 35 matching lines @@
       file('foo.dart', 'main() => "foo";')
     ]).scheduleCreate();
 
     appDir([{"git": "../foo.git"}]).scheduleCreate();
 
     schedulePub(args: ['install'],
         output: const RegExp(@"Dependencies installed!$"));
 
     dir(cachePath, [
       dir('git', [
-        dir('cache', [gitPackageCacheDir('foo')]),
-        gitPackageCacheDir('foo')
+        dir('cache', [gitPackageRepoCacheDir('foo')]),
+        gitPackageRevisionCacheDir('foo')
       ])
     ]).scheduleValidate();
 
     dir(packagesPath, [
       dir('foo', [
         file('foo.dart', 'main() => "foo";')
       ])
     ]).scheduleValidate();
 
     // TODO(nweiz): remove this once we support pub update
     dir(packagesPath).scheduleDelete();
     file('$appPath/pubspec.lock', '').scheduleDelete();
 
     git('foo.git', [
       file('foo.dart', 'main() => "foo 2";')
     ]).scheduleCommit();
 
     schedulePub(args: ['install'],
         output: const RegExp(@"Dependencies installed!$"));
 
     // When we download a new version of the git package, we should re-use the
     // git/cache directory but create a new git/ directory.
     dir(cachePath, [
       dir('git', [
-        dir('cache', [gitPackageCacheDir('foo', 2)]),
-        gitPackageCacheDir('foo'),
-        gitPackageCacheDir('foo', 2)
+        dir('cache', [gitPackageRepoCacheDir('foo')]),
+        gitPackageRevisionCacheDir('foo'),
+        gitPackageRevisionCacheDir('foo', 2)
       ])
     ]).scheduleValidate();
 
     dir(packagesPath, [
       dir('foo', [
         file('foo.dart', 'main() => "foo 2";')
       ])
     ]).scheduleValidate();
 
     run();
   });
 
   test('checks out a package from Git twice', () {
     ensureGit();
 
     git('foo.git', [
       file('foo.dart', 'main() => "foo";')
     ]).scheduleCreate();
 
     appDir([{"git": "../foo.git"}]).scheduleCreate();
 
     schedulePub(args: ['install'],
         output: const RegExp(@"Dependencies installed!$"));
 
     dir(cachePath, [
       dir('git', [
-        dir('cache', [gitPackageCacheDir('foo')]),
-        gitPackageCacheDir('foo')
+        dir('cache', [gitPackageRepoCacheDir('foo')]),
+        gitPackageRevisionCacheDir('foo')
       ])
     ]).scheduleValidate();
 
     dir(packagesPath, [
       dir('foo', [
         file('foo.dart', 'main() => "foo";')
       ])
     ]).scheduleValidate();
 
     // TODO(nweiz): remove this once we support pub update
@@ skipping 27 matching lines @@
 
     dir(packagesPath, [
       dir('foo', [
         file('foo.dart', 'main() => "foo 1";')
       ])
     ]).scheduleValidate();
 
     run();
   });
 
+  test('checks out a package at a specific branch from Git', () {
+    ensureGit();
+
+    var repo = git('foo.git', [
+      file('foo.dart', 'main() => "foo 1";')
+    ]);
+    repo.scheduleCreate();
+    repo.scheduleGit(["branch", "old"]);
+
+    git('foo.git', [
+      file('foo.dart', 'main() => "foo 2";')
+    ]).scheduleCommit();
+
+    appDir([{"git": {"url": "../foo.git", "ref": "old"}}]).scheduleCreate();
+
+    schedulePub(args: ['install'],
+        output: const RegExp(@"Dependencies installed!$"));
+
+    dir(packagesPath, [
+      dir('foo', [
+        file('foo.dart', 'main() => "foo 1";')
+      ])
+    ]).scheduleValidate();
+
+    run();
+  });
+
   test('keeps a Git package locked to the version in the lockfile', () {
     ensureGit();
 
     git('foo.git', [
       file('foo.dart', 'main() => "foo";')
     ]).scheduleCreate();
 
     appDir([{"git": "../foo.git"}]).scheduleCreate();
 
     // This install should lock the foo.git dependency to the current revision.
@@ skipping 110 matching lines @@
         file('foo.dart', 'main() => "foo";')
       ]).scheduleCreate();
 
       appDir([{"git": "../foo.git/"}]).scheduleCreate();
 
       schedulePub(args: ['install'],
           output: const RegExp(@"Dependencies installed!$"));
 
       dir(cachePath, [
         dir('git', [
-          dir('cache', [gitPackageCacheDir('foo')]),
-          gitPackageCacheDir('foo')
+          dir('cache', [gitPackageRepoCacheDir('foo')]),
+          gitPackageRevisionCacheDir('foo')
         ])
       ]).scheduleValidate();
 
       dir(packagesPath, [
         dir('foo', [
           file('foo.dart', 'main() => "foo";')
         ])
       ]).scheduleValidate();
 
       run();
     });
   });
 }