Support subcommands in pub and pub help.

sdk/lib/_internal/pub/bin/pub.dart

Index: sdk/lib/_internal/pub/bin/pub.dart
diff --git a/sdk/lib/_internal/pub/bin/pub.dart b/sdk/lib/_internal/pub/bin/pub.dart
index a589dcc8403a9ac31593a593ad2afb4545c1f627..533efdbaef9e36ca94dc4b9c1436f877603bbb58 100644
--- a/sdk/lib/_internal/pub/bin/pub.dart
+++ b/sdk/lib/_internal/pub/bin/pub.dart
@@ -38,18 +38,6 @@ void main(List<String> arguments) {
     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();
   }
@@ -82,10 +70,62 @@ void main(List<String> arguments) {
   }
 
   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() {