Add validation infrastructure for "pub lish".

utils/pub/pub.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.
 
 /**
  * The main entrypoint for the pub command line application.
  */
 library pub;
 
 import '../../pkg/args/lib/args.dart';
 import 'dart:io';
 import 'dart:math';
 import 'io.dart';
 import 'command_help.dart';
 import 'command_install.dart';
 import 'command_lish.dart';
 import 'command_update.dart';
 import 'command_version.dart';
 import 'entrypoint.dart';
 import 'exit_codes.dart' as exit_codes;
-import 'git_source.dart';
-import 'hosted_source.dart';
 import 'package.dart';
 import 'pubspec.dart';
-import 'sdk_source.dart';
 import 'source.dart';
 import 'source_registry.dart';
 import 'system_cache.dart';
 import 'utils.dart';
 import 'version.dart';
 
 Version get pubVersion => new Version(0, 0, 0);
 
 /**
  * The commands that Pub understands.
@@ skipping 54 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 = join(appData, 'Pub', 'Cache');
   } else {
     cacheDir = '${Platform.environment['HOME']}/.pub-cache';
   }
 
-  var cache = new SystemCache(cacheDir);
-  cache.register(new SdkSource(sdkDir));
-  cache.register(new GitSource());
-  cache.register(new HostedSource());
-  cache.sources.setDefault('hosted');
+  var cache = new SystemCache.withSources(cacheDir, sdkDir);
 
   // Select the command.
   var command = pubCommands[globalOptions.rest[0]];
   if (command == null) {
     printError('Could not find a command named "${globalOptions.rest[0]}".');
     printError('Run "pub help" to see available commands.');
     exit(exit_codes.USAGE);
     return;
   }
 
@@ skipping 101 matching lines @@
       }
 
       exit(_chooseExitCode(error));
     }
 
     var future = new Future.immediate(null);
     if (requiresEntrypoint) {
       // TODO(rnystrom): Will eventually need better logic to walk up
       // subdirectories until we hit one that looks package-like. For now, just
       // assume the cwd is it.
-      future = Package.load(null, currentWorkingDir, cache.sources)
-          .transform((package) => new Entrypoint(package, cache));
+      future = Entrypoint.load(currentWorkingDir, cache);
     }
 
     future = future.chain((entrypoint) {
       this.entrypoint = entrypoint;
       try {
         var commandFuture = onRun();
         if (commandFuture == null) return new Future.immediate(true);
 
         return commandFuture;
       } catch (error, trace) {
@@ skipping 48 matching lines @@
     if (exception is HttpException || exception is HttpParserException ||
         exception is SocketIOException || exception is PubHttpException) {
       return exit_codes.UNAVAILABLE;
     } else if (exception is FormatException) {
       return exit_codes.DATA;
     } else {
       return 1;
     }
   }
 }