Make "pub help" show global help.

sdk/lib/_internal/pub/bin/pub.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.
 
 import 'dart:async';
 import 'dart:io';
-import 'dart:math' as math;
 
 import 'package:args/args.dart';
 import 'package:path/path.dart' as path;
 
 import '../lib/src/command.dart';
 import '../lib/src/exit_codes.dart' as exit_codes;
 import '../lib/src/io.dart';
 import '../lib/src/log.dart' as log;
 import '../lib/src/sdk.dart' as sdk;
 import '../lib/src/utils.dart';
 
-final pubArgParser = initArgParser();
-
 void main(List<String> arguments) {
   ArgResults options;
 
   try {
-    options = pubArgParser.parse(arguments);
+    options = PubCommand.pubArgParser.parse(arguments);
   } on FormatException catch (e) {
     log.error(e.message);
     log.error('Run "pub help" to see available options.');
     flushThenExit(exit_codes.USAGE);
     return;
   }
 
   if (options['version']) {
     log.message('Pub ${sdk.version}');
     return;
   }
 
   if (options['help']) {
-    printUsage();
+    PubCommand.printGlobalUsage();
     return;
   }
 
   if (options.command == null) {
     if (options.rest.isEmpty) {
       // No command was chosen.
-      printUsage();
+      PubCommand.printGlobalUsage();
     } else {
       log.error('Could not find a command named "${options.rest[0]}".');
       log.error('Run "pub help" to see available commands.');
       flushThenExit(exit_codes.USAGE);
     }
     return;
   }
 
   if (options['trace']) {
     log.recordTranscript();
@@ skipping 24 matching lines @@
     cacheDir = path.join(appData, 'Pub', 'Cache');
   } else {
     cacheDir = '${Platform.environment['HOME']}/.pub-cache';
   }
 
   validatePlatform().then((_) {
     PubCommand.commands[options.command.name].run(cacheDir, options, arguments);
   });
 }
 
-ArgParser initArgParser() {
-  var argParser = new ArgParser();
-
-  // Add the global options.
-  argParser.addFlag('help', abbr: 'h', negatable: false,
-      help: 'Print this usage information.');
-  argParser.addFlag('version', negatable: false,
-      help: 'Print pub version.');
-  argParser.addFlag('trace',
-       help: 'Print debugging information when an error occurs.');
-  argParser.addOption('verbosity',
-      help: 'Control output verbosity.',
-      allowed: ['normal', 'io', 'solver', 'all'],
-      allowedHelp: {
-        'normal': 'Show errors, warnings, and user messages.',
-        'io':     'Also show IO operations.',
-        'solver': 'Show steps during version resolution.',
-        'all':    'Show all output including internal tracing messages.'
-      });
-  argParser.addFlag('verbose', abbr: 'v', negatable: false,
-      help: 'Shortcut for "--verbosity=all".');
-
-  // Register the commands.
-  PubCommand.commands.forEach((name, command) {
-    argParser.addCommand(name, command.commandParser);
-  });
-
-  return argParser;
-}
-
 /// Checks that pub is running on a supported platform. If it isn't, it prints
 /// an error message and exits. Completes when the validation is done.
 Future validatePlatform() {
   return syncFuture(() {
     if (Platform.operatingSystem != 'windows') return null;
 
     return runProcess('ver', []).then((result) {
       if (result.stdout.join('\n').contains('XP')) {
         log.error('Sorry, but pub is not supported on Windows XP.');
         return flushThenExit(exit_codes.USAGE);
       }
     });
   });
 }
-
-/// Displays usage information for the app.
-void printUsage([String description = 'Pub is a package manager for Dart.']) {
-  // Build up a buffer so it shows up as a single log entry.
-  var buffer = new StringBuffer();
-  buffer.write(description);
-  buffer.write('\n\n');
-  buffer.write('Usage: pub command [arguments]\n\n');
-  buffer.write('Global options:\n');
-  buffer.write('${pubArgParser.getUsage()}\n\n');
-
-  // Show the commands sorted.
-  buffer.write('Available commands:\n');
-
-  // TODO(rnystrom): A sorted map would be nice.
-  int length = 0;
-  var names = <String>[];
-  for (var command in PubCommand.commands.keys) {
-    // Hide aliases.
-    if (PubCommand.commands[command].aliases.indexOf(command) >= 0) continue;
-
-    // Hide undocumented commands.
-    if (PubCommand.commands[command].hidden) continue;
-
-    length = math.max(length, command.length);
-    names.add(command);
-  }
-
-  names.sort((a, b) => a.compareTo(b));
-
-  for (var name in names) {
-    buffer.write('  ${padRight(name, length)}   '
-        '${PubCommand.commands[name].description}\n');
-  }
-
-  buffer.write('\n');
-  buffer.write(
-      'Use "pub help [command]" for more information about a command.');
-  log.message(buffer.toString());
-}