Implement 'print', 'up', 'down', and 'frame' commands in the 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 106 matching lines @@
 
   // Locals + subcommands, show all.
   cmd.completeCommand('count ').then((result) {
       expect(result, equals(['count chocula ',
                              'count one ',
                              'count two ',
                              'count three ']));
   });
 
   // Locals + subcommands, single local match.
-  cmd.completeCommand('count th ').then((result) {
+  cmd.completeCommand('count th').then((result) {
     expect(result, equals(['count three ']));
   });
 
   // Locals + subcommands, ambiguous local match.
   cmd.completeCommand('count t').then((result) {
     expect(result, equals(['count two ', 'count three ']));
   });
 
   // Locals + subcommands, single command match.
   cmd.completeCommand('co choc').then((result) {
     expect(result, equals(['co chocula ']));
   });
 
-  // We gobble spare spaces, even in the prefix.
+  // We gobble spare spaces in the prefix but not elsewhere.
   cmd.completeCommand('    game    chec').then((result) {
-    expect(result, equals(['game checkers ']));
+    expect(result, equals(['game    checkers ']));
   });
 }
 
 void testCommandRunSimple() {
   // Run a simple command.
   StringBuffer out = new StringBuffer();
   RootCommand cmd = new RootCommand([new TestCommand(out, 'alpha', [])]);
 
   // Full name dispatch works.  Argument passing works.
   cmd.runCommand('alpha dog').then(expectAsync((_) {
       expect(out.toString(), contains('executing alpha([dog])\n'));
       out.clear();
       // Substring dispatch works.
       cmd.runCommand('al cat mouse').then(expectAsync((_) {
-          expect(out.toString(), contains('executing alpha([cat, mouse])\n'));
+          expect(out.toString(), contains('executing alpha([cat , mouse])\n'));
       }));
   }));
 }
 
 void testCommandRunSubcommand() {
   // Run a simple command.
   StringBuffer out = new StringBuffer();
   RootCommand cmd =
       new RootCommand([
           new TestCommand(out, 'alpha', [
@@ skipping 49 matching lines @@
 
 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);
 }