add cache list command to pub

utils/tests/pub/pub_cache_test.dart

+// Copyright (c) 2013, 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_cache_test;
+
+import 'dart:io';
+import 'dart:json' as json;
+import 'test_pub.dart';
+import '../../pub/io.dart';
+
+main() {
+  initConfig();
+  
+  integration('running pub cache displays error message', () {
+    schedulePub(args: ['cache'], 
+        output: '''
+          Inspect the system cache.
+
+          Usage: pub cache list
+          ''',
+        error: 'The cache command expects one argument.',
+        exitCode: 64);
+  });
+  
+  integration('running pub cache foo displays error message', () {
+    schedulePub(args: ['cache' ,'foo'], 
+        output: '''
+          Inspect the system cache.
+
+          Usage: pub cache list
+          ''',
+        error: 'Unknown cache command "foo".',
+        exitCode: 64);
+  });
+  
+  integration('running pub cache list when there is no cache', () {      
+    schedulePub(args: ['cache', 'list'], exitCode: 1);

[Bob Nystrom, 2013/03/13 18:23:24]

I think should actually pass. If you don't have a cache, that should be
equivalent to an empty cache from the user's perspective. Pub should gracefully
handle that case.

[keertip, 2013/03/13 20:40:29]

Done.

+  });
+  
+  integration('running pub cache list on empty cache', () {      
+    // Set up a cache.
+    dir(cachePath, [
+      dir('hosted', [
+         dir('pub.dartlang.org', [
+        ])
+      ])
+    ]).scheduleCreate();
+    
+    schedulePub(args: ['cache', 'list'], output: '{"packages":{}}');
+  });
+  
+  integration('running pub cache list', () {
+    // Set up a cache.
+    dir(cachePath, [
+      dir('hosted', [
+         dir('pub.dartlang.org', [
+          dir("foo-1.2.3", [
+            libPubspec("foo", "1.2.3"),
+            libDir("foo")
+          ]),
+          dir("bar-2.0.0", [
+            libPubspec("bar", "2.0.0"),
+            libDir("bar") ])
+        ])
+      ])
+    ]).scheduleCreate();
+    
+    schedulePub(args: ['cache', 'list'], output: 
+      new RegExp(r'\{"packages":\{"bar":\{"version":"2\.0\.0","location":"[^"]+bar-2\.0\.0"\},"foo":\{"version":"1\.2\.3","location":"[^"]+foo-1\.2\.3"\}\}\}$'));
+  });
+  
+}