Add "pub global list" command to show all globally activated packages.

sdk/lib/_internal/pub/test/global/list_test.dart

+// Copyright (c) 2014, 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 'package:path/path.dart' as p;
+
+import '../../lib/src/io.dart';
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+
+main() {
+  initConfig();
+
+  integration('lists an activated hosted package', () {
+    servePackages([
+      packageMap('foo', '1.0.0')
+    ]);
+
+    schedulePub(args: ['global', 'activate', 'foo']);
+
+    schedulePub(args: ['global', 'list'], output: 'foo 1.0.0');
+  });
+
+  integration('lists an activated Git package', () {
+    ensureGit();
+
+    d.git('foo.git', [
+      d.libPubspec('foo', '1.0.0'),
+      d.dir('bin', [
+        d.file('foo.dart', 'main() => print("ok");')
+      ])
+    ]).create();
+
+    schedulePub(args: ['global', 'activate', '-sgit', '../foo.git']);
+
+    schedulePub(args: ['global', 'list'],
+        output: 'foo 1.0.0 from Git repository "../foo.git"');
+  });
+
+  integration('lists an activated Path package', () {
+    d.dir('foo', [
+      d.libPubspec('foo', '1.0.0'),
+      d.dir('bin', [
+        d.file('foo.dart', 'main() => print("ok");')
+      ])
+    ]).create();
+
+    schedulePub(args: ['global', 'activate', '-spath', '../foo']);
+
+    var path = canonicalize(p.join(sandboxDir, 'foo'));
+    schedulePub(args: ['global', 'list'],
+        output: 'foo 1.0.0 at path "$path"');
+  });
+
+  integration('lists activated packages in alphabetical order', () {
+    servePackages([
+      packageMap('aaa', '1.0.0'),
+      packageMap('bbb', '1.0.0'),
+      packageMap('ccc', '1.0.0')
+    ]);
+
+    schedulePub(args: ['global', 'activate', 'ccc']);
+    schedulePub(args: ['global', 'activate', 'aaa']);
+    schedulePub(args: ['global', 'activate', 'bbb']);
+
+    schedulePub(args: ['global', 'list'], output: '''
+aaa 1.0.0
+bbb 1.0.0
+ccc 1.0.0
+''');
+  });
+
+  integration('lists nothing when no packages activated', () {
+    schedulePub(args: ['global', 'list'], output: '\n');
+  });
+}