Update pub to use the new command runner API in args.

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 'package:args/args.dart';
-import 'package:http/http.dart' as http;
-import 'package:path/path.dart' as path;
-import 'package:stack_trace/stack_trace.dart';
-
-import '../lib/src/command.dart';
-import '../lib/src/exceptions.dart';
-import '../lib/src/exit_codes.dart' as exit_codes;
-import '../lib/src/http.dart';
-import '../lib/src/io.dart';
-import '../lib/src/log.dart' as log;
-import '../lib/src/sdk.dart' as sdk;
-import '../lib/src/solver/version_solver.dart';
-import '../lib/src/utils.dart';
+import '../lib/src/command_runner.dart';
 
 void main(List<String> arguments) {
-  ArgResults options;
-
-  try {
-    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;
-  }
-
-  log.withPrejudice = options['with-prejudice'];
-
-  if (options['version']) {
-    log.message('Pub ${sdk.version}');
-    return;
-  }
-
-  if (options['help']) {
-    PubCommand.printGlobalUsage();
-    return;
-  }
-
-  if (options['trace']) {
-    log.recordTranscript();
-  }
-
-  switch (options['verbosity']) {
-    case 'normal': log.verbosity = log.Verbosity.NORMAL; break;
-    case 'io':     log.verbosity = log.Verbosity.IO; break;
-    case 'solver': log.verbosity = log.Verbosity.SOLVER; break;
-    case 'all':    log.verbosity = log.Verbosity.ALL; break;
-    default:
-      // No specific verbosity given, so check for the shortcut.
-      if (options['verbose']) {
-        log.verbosity = log.Verbosity.ALL;
-      }
-      break;
-  }
-
-  log.fine('Pub ${sdk.version}');
-
-  var cacheDir;
-  if (Platform.environment.containsKey('PUB_CACHE')) {
-    cacheDir = Platform.environment['PUB_CACHE'];
-  } else if (Platform.operatingSystem == 'windows') {
-    var appData = Platform.environment['APPDATA'];
-    cacheDir = path.join(appData, 'Pub', 'Cache');
-  } else {
-    cacheDir = '${Platform.environment['HOME']}/.pub-cache';
-  }
-
-  validatePlatform().then((_) => runPub(cacheDir, options, arguments));
+  new PubCommandRunner().run(arguments);
 }
-
-/// Runs the appropriate pub command whose [arguments] have been parsed to
-/// [options] using the system cache in [cacheDir].
-///
-/// Handles and correctly reports any errors that occur while running.
-void runPub(String cacheDir, ArgResults options, List<String> arguments) {
-  var captureStackChains =
-      options['trace'] ||
-      options['verbose'] ||
-      options['verbosity'] == 'all';
-
-  captureErrors(() => invokeCommand(cacheDir, options),
-      captureStackChains: captureStackChains).catchError((error, Chain chain) {
-    log.exception(error, chain);
-
-    if (options['trace']) {
-      log.dumpTranscript();
-    } else if (!isUserFacingException(error)) {
-      log.error("""
-This is an unexpected error. Please run
-
-    pub --trace ${arguments.map((arg) => "'$arg'").join(' ')}
-
-and include the results in a bug report on http://dartbug.com/new.
-""");
-    }
-
-    return flushThenExit(chooseExitCode(error));
-  }).then((_) {
-    // Explicitly exit on success to ensure that any dangling dart:io handles
-    // don't cause the process to never terminate.
-    return flushThenExit(exit_codes.SUCCESS);
-  });
-}
-
-/// Returns the appropriate exit code for [exception], falling back on 1 if no
-/// appropriate exit code could be found.
-int chooseExitCode(exception) {
-  while (exception is WrappedException) exception = exception.innerError;
-
-  if (exception is HttpException || exception is http.ClientException ||
-      exception is SocketException || exception is PubHttpException ||
-      exception is DependencyNotFoundException) {
-    return exit_codes.UNAVAILABLE;
-  } else if (exception is FormatException || exception is DataException) {
-    return exit_codes.DATA;
-  } else if (exception is UsageException) {
-    return exit_codes.USAGE;
-  } else {
-    return 1;
-  }
-}
-
-/// Walks the command tree and runs the selected pub command.
-Future invokeCommand(String cacheDir, ArgResults mainOptions) async {
-  var commands = PubCommand.mainCommands;
-  var command;
-  var commandString = "pub";
-  var options = mainOptions;
-
-  while (commands.isNotEmpty) {
-    if (options.command == null) {
-      if (options.rest.isEmpty) {
-        if (command == null) {
-          // No top-level command was chosen.
-          PubCommand.printGlobalUsage();
-          return new Future.value();
-        }
-
-        command.usageError('Missing subcommand for "$commandString".');
-      } else {
-        if (command == null) {
-          PubCommand.usageErrorWithCommands(commands,
-              'Could not find a command named "${options.rest[0]}".');
-        }
-
-        command.usageError('Could not find a subcommand named '
-            '"${options.rest[0]}" for "$commandString".');
-      }
-    }
-
-    // Step into the command.
-    options = options.command;
-    command = commands[options.name];
-    commands = command.subcommands;
-    commandString += " ${options.name}";
-
-    if (options['help']) {
-      command.printUsage();
-      return new Future.value();
-    }
-  }
-
-  // Make sure there aren't unexpected arguments.
-  if (!command.takesArguments && options.rest.isNotEmpty) {
-    command.usageError(
-        'Command "${options.name}" does not take any arguments.');
-  }
-
-  try {
-    // TODO(rnystrom): Use await here when this is fixed:
-    // https://github.com/dart-lang/async_await/issues/40.
-    return command.run(cacheDir, mainOptions, options);
-  } finally {
-    command.cache.deleteTempDir();
-  }
-}
-
-/// 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() async {
-  if (Platform.operatingSystem != 'windows') return;
-
-  var result = await runProcess('ver', []);
-  if (result.stdout.join('\n').contains('XP')) {
-    log.error('Sorry, but pub is not supported on Windows XP.');
-    await flushThenExit(exit_codes.USAGE);
-  }
-}