Allow command aliases in Observatory debugger.

runtime/observatory/test/command_test.dart

 // Copyright (c) 2015, 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 'dart:async';
 
 import 'package:observatory/cli.dart';
 import 'package:unittest/unittest.dart';
 
 class TestCommand extends Command {
@@ skipping 185 matching lines @@
 
   cmd.runCommand('a 55').catchError(expectAsync((e) {
       expect(e, equals('ambiguous'));
       out.clear();
       cmd.runCommand('ankl 55').then(expectAsync((_) {
           expect(out.toString(), equals('executing ankle([55])\n'));
       }));
   }));
 }
 
+void testCommandRunAlias() {
+  // Run a simple command.
+  StringBuffer out = new StringBuffer();
+  var aliasCmd = new TestCommand(out, 'alpha', []);
+  aliasCmd.alias = 'a';
+  RootCommand cmd = new RootCommand([aliasCmd,
+                                     new TestCommand(out, 'ankle', [])]);
+
+  cmd.runCommand('a 55').then(expectAsync((_) {
+    expect(out.toString(), equals('executing alpha([55])\n'));
+  }));
+}
+
 main() {
   test('command completion test suite', testCommandComplete);
   test('run a simple command', testCommandRunSimple);
   test('run a subcommand', testCommandRunSubcommand);
   test('run a command which is not found', testCommandRunNotFound);
   test('run a command which is ambiguous', testCommandRunAmbiguous);
+  test('run a command using an alias', testCommandRunAlias);
 }