Add a pub command for managing uploaders for packages.

utils/pub/oauth2.dart

 // Copyright (c) 2012, 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.
 
 library oauth2;
 
 import 'dart:io';
 import 'dart:uri';
 
 // TODO(nweiz): Make this a "package:" URL, or something nicer than this.
@@ skipping 44 matching lines @@
   return fileExists(credentialsFile).chain((exists) {
     if (exists) return deleteFile(credentialsFile);
     return new Future.immediate(null);
   });
 }
 
 /// Asynchronously passes an OAuth2 [Client] to [fn], and closes the client when
 /// the [Future] returned by [fn] completes.
 ///
 /// This takes care of loading and saving the client's credentials, as well as
-/// prompting the user for their authorization.
+/// prompting the user for their authorization. It will also re-authorize and
+/// re-run [fn] if a recoverable authorization error is detected.
 Future withClient(SystemCache cache, Future fn(Client client)) {
   return _getClient(cache).chain((client) {
     var completer = new Completer();
     var future = fn(client);
     future.onComplete((_) {
       try {
         client.close();
         // Be sure to save the credentials even when an error happens. Also be
         // sure to pipe the exception from `future` to `completer`.
         chainToCompleter(
             _saveCredentials(cache, client.credentials).chain((_) => future),
             completer);
       } catch (e, stackTrace) {
         // onComplete will drop exceptions on the floor. We want to ensure that
         // any programming errors here don't go un-noticed. See issue 4127.
         completer.completeException(e, stackTrace);
       }
     });
     return completer.future;
+  }).transformException((e) {
+    if (e is ExpirationException) {
+      log.error("Pub's authorization to upload packages has expired and "
+          "can't be automatically refreshed.");
+      return withClient(cache, fn);

[Bob Nystrom, 2012/12/17 18:41:58]

Do we need to guard against getting stuck in an infinite loop here?

[nweiz, 2012/12/17 21:18:48]

I don't think so -- even if the server keeps sending out-of-date credentials,
the user will have to perform an action each time, so it won't silently block
forever.

+    } else if (e is AuthorizationException) {
+      var message = "OAuth2 authorization failed";
+      if (e.description != null) message = "$message (${e.description})";
+      log.error("$message.");
+      return clearCredentials(cache).chain((_) => withClient(cache, fn));
+    } else {
+      throw e;
+    }
   });
 }
 
 /// Gets a new OAuth2 client. If saved credentials are available, those are
 /// used; otherwise, the user is prompted to authorize the pub client.
 Future<Client> _getClient(SystemCache cache) {
   return _loadCredentials(cache).chain((credentials) {
     if (credentials == null) return _authorize();
     return new Future.immediate(new Client(
         _identifier, _secret, credentials, httpClient: curlClient));
@@ skipping 98 matching lines @@
       'Pub needs your authorization to upload packages on your behalf.\n'
       'In a web browser, go to $authUrl\n'
       'Then click "Allow access".\n\n'
       'Waiting for your authorization...');
 
   return completer.future.transform((client) {
     log.message('Successfully authorized.\n');
     return client;
   });
 }