Support subcommands in pub and pub 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 'package:args/args.dart';
 import 'package:path/path.dart' as path;
 
@@ skipping 20 matching lines @@
   if (options['version']) {
     log.message('Pub ${sdk.version}');
     return;
   }
 
   if (options['help']) {
     PubCommand.printGlobalUsage();
     return;
   }
 
-  if (options.command == null) {
-    if (options.rest.isEmpty) {
-      // No command was chosen.
-      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();
   }
 
   switch (options['verbosity']) {
     case 'normal': log.showNormal(); break;
     case 'io':     log.showIO(); break;
     case 'solver': log.showSolver(); break;
     case 'all':    log.showAll(); break;
     default:
@@ skipping 11 matching lines @@
   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((_) {

[nweiz, 2014/01/31 21:42:06]

Nit: =>

[Bob Nystrom, 2014/02/01 01:49:32]

Done.

-    PubCommand.commands[options.command.name].run(cacheDir, options, arguments);
+    runCommand(cacheDir, options, arguments);
   });
 }
 
+void runCommand(String cacheDir, ArgResults mainOptions,

[nweiz, 2014/01/31 21:42:06]

Document this.

[Bob Nystrom, 2014/02/01 01:49:32]

Done.

+                List<String> arguments) {
+  // Walk down the commands and subcommands until we hit a leaf.
+  var commands = PubCommand.mainCommands;
+  var command;
+  var commandString = "pub";
+  var options = mainOptions;
+
+  _usageError(message) {
+    var buffer = new StringBuffer();
+    buffer.writeln(message);
+    PubCommand.listCommands(commands, buffer, isSubcommand: command != null);
+    log.error(buffer);
+    flushThenExit(exit_codes.USAGE);
+  }
+
+  while (commands.isNotEmpty) {
+    if (options['help']) {
+      command.printUsage();
+      return;
+    }
+
+    if (options.command == null) {
+      if (options.rest.isEmpty) {
+        if (command == null) {
+          // No top-level command was chosen.
+          PubCommand.printGlobalUsage();
+        } else {
+          _usageError('Missing subcommand for "$commandString".');
+        }
+      } else {
+        if (command == null) {
+          _usageError('Could not find a command named "${options.rest[0]}".');

[nweiz, 2014/01/31 21:42:06]

"find" seems weird here -- it's not like the command is somewhere and we
misplaced it, it just doesn't exist.

[Bob Nystrom, 2014/02/01 01:49:32]

<shrug> It's the same message we had before. I think it's a more polite way than
saying "you're wrong!"

+        } else {
+          _usageError('Could not find a subcommand named "${options.rest[0]}" '
+              'for "$commandString".');
+        }
+      }
+
+      return;
+    }
+
+    // Step into the command.
+    options = options.command;
+    command = commands[options.name];
+    commands = command.subcommands;
+    commandString += " ${options.name}";
+  }
+
+  command.run(cacheDir, mainOptions, options, arguments);
+}
+
 /// 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);
       }
     });
   });
 }