Port of github.com/polymer/polymer.

pkg/polymer/lib/src/build/runner.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.
 
 /**
  * Definitions used to run the polymer linter and deploy tools without using
  * pub serve or pub deploy.
  */
 library polymer.src.build.runner;
 
@@ skipping 87 matching lines @@
   map[currentPackage] = '.';
   return map;
 }
 
 /** Internal packages used by polymer. */
 // TODO(sigmund): consider computing this list by recursively parsing
 // pubspec.yaml files in the `Options.packageDirs`.
 final Set<String> _polymerPackageDependencies = [
     'analyzer_experimental', 'args', 'barback', 'browser', 'csslib',
     'custom_element', 'fancy_syntax', 'html5lib', 'html_import', 'js',
-    'logging', 'mdv', 'meta', 'mutation_observer', 'observe', 'path', 'polymer',
+    'logging', 'mdv', 'meta', 'mutation_observer', 'observe', 'path'
     'polymer_expressions', 'serialization', 'shadow_dom', 'source_maps',
     'stack_trace', 'unittest', 'unmodifiable_collection', 'yaml'].toSet();
 
 /** Return the relative path of each file under [subDir] in [package]. */
 Iterable<String> _listPackageDir(String package, String subDir,
     BarbackOptions options) {
   var packageDir = options.packageDirs[package];
   if (packageDir == null) return const [];
   var dir = new Directory(path.join(packageDir, subDir));
   if (!dir.existsSync()) return const [];
@@ skipping 23 matching lines @@
 /** Tell barback which transformers to use and which assets to process. */
 void _initBarback(Barback barback, BarbackOptions options) {
   var assets = [];
   void addAssets(String package, String subDir) {
     for (var filepath in _listPackageDir(package, subDir, options)) {
       assets.add(new AssetId(package, filepath));
     }
   }
 
   for (var package in options.packageDirs.keys) {
-    // There is nothing to do in the 'polymer' package and its dependencies.
+    // There is nothing to do in the polymer package dependencies.
+    // However: in Polymer package *itself*, we need to replace ObservableMixin
+    // with ChangeNotifierMixin.
     if (!options.transformPolymerDependencies &&
         _polymerPackageDependencies.contains(package)) continue;
     barback.updateTransformers(package, options.phases);
 
     // Notify barback to process anything under 'lib' and 'asset'.
     addAssets(package, 'lib');
     addAssets(package, 'asset');
   }
 
   // In case of the current package, include also 'web'.
@@ skipping 140 matching lines @@
   return writer.addStream(new File(inpath).openRead())
       .then((_) => writer.close());
 }
 
 /** Write contents of an [asset] into a file at [filepath]. */
 Future _writeAsset(String filepath, Asset asset) {
   _ensureDir(path.dirname(filepath));
   var writer = new File(filepath).openWrite();
   return writer.addStream(asset.read()).then((_) => writer.close());
 }