feat(transformers): directive aliases in Dart transformers (fix #1747)

modules/angular2/src/forms/form_builder.ts

@@ -1,3 +1,4 @@
+import {Injectable} from 'angular2/di';
 import {StringMapWrapper, ListWrapper, List} from 'angular2/src/facade/collection';
 import {isPresent, isArray} from 'angular2/src/facade/lang';
 import * as modelModule from './model';
@@ -67,6 +68,7 @@ import * as modelModule from './model';
  *
  *  ```
  */
+@Injectable()
 export class FormBuilder {
   group(controlsConfig: StringMap<string, any>,
         extra: StringMap<string, any> = null): modelModule.ControlGroup {

modules/angular2/src/transform/common/names.dart

@@ -6,6 +6,9 @@ const REFLECTOR_VAR_NAME = 'reflector';
 const TRANSFORM_DYNAMIC_MODE = 'transform_dynamic';
 const DEPS_EXTENSION = '.ng_deps.dart';
 const META_EXTENSION = '.ng_meta.json';
+// TODO(sigmund): consider merging into .ng_meta by generating local metadata
+// upfront (rather than extracting it from ng_deps).
+const ALIAS_EXTENSION = '.aliases.json';
 const REFLECTION_CAPABILITIES_NAME = 'ReflectionCapabilities';
 const REGISTER_TYPE_METHOD_NAME = 'registerType';
 const REGISTER_GETTERS_METHOD_NAME = 'registerGetters';
@@ -20,6 +23,10 @@ String toMetaExtension(String uri) =>
 String toDepsExtension(String uri) =>
     _toExtension(uri, const [META_EXTENSION, '.dart'], DEPS_EXTENSION);
 
+/// Returns `uri` with its extension updated to [ALIAS_EXTENSION].
+String toAliasExtension(String uri) =>
+    _toExtension(uri, const [DEPS_EXTENSION, '.dart'], ALIAS_EXTENSION);
+
 /// Returns `uri` with its extension updated to `toExtension` if its
 /// extension is currently in `fromExtension`.
 String _toExtension(

modules/angular2/src/transform/common/ng_meta.dart

@@ -0,0 +1,88 @@
+library angular2.transform.common.ng_meta;
+
+import 'package:angular2/src/render/api.dart';
+import 'package:angular2/src/render/dom/convert.dart';
+import 'logging.dart';
+
+/// Metadata about directives and directive aliases.
+///
+/// [NgMeta] is used in three stages of the transformation process. First we
+/// store directive aliases exported from a single file in an [NgMeta] instance.
+/// Later we use another [NgMeta] instance to store more information about a
+/// single file, including both directive aliases and directives extracted from
+/// the corresponding `.ng_deps.dart` file.  Further down the compilation
+/// process, the template compiler needs to reason about the namespace of import
+/// prefixes, so it will combine multple [NgMeta] instances together if they
+/// were imported into a file with the same prefix.
+///
+/// Instances of this class are serialized into `.aliases.json` and
+/// `.ng_meta.json` files as intermediate assets to make the compilation process
+/// easier.
+class NgMeta {
+  /// Directive metadata for each type annotated as a directive.
+  final Map<String, DirectiveMetadata> types;
+
+  /// List of other types and names associated with a given name.
+  final Map<String, List<String>> aliases;
+
+  NgMeta(this.types, this.aliases);
+
+  NgMeta.empty() : this({}, {});
+
+  bool get isEmpty => types.isEmpty && aliases.isEmpty;
+
+  /// Parse from the serialized form produced by [toJson].
+  factory NgMeta.fromJson(Map json) {
+    var types = {};
+    var aliases = {};
+    for (var key in json.keys) {
+      var entry = json[key];
+      if (entry['kind'] == 'type') {
+        types[key] = directiveMetadataFromMap(entry['value']);
+      } else if (entry['kind'] == 'alias') {
+        aliases[key] = entry['value'];
+      }
+    }
+    return new NgMeta(types, aliases);
+  }
+
+  /// Serialized representation of this instance.
+  Map toJson() {
+    var result = {};
+    types.forEach((k, v) {
+      result[k] = {'kind': 'type', 'value': directiveMetadataToMap(v)};
+    });
+
+    aliases.forEach((k, v) {
+      result[k] = {'kind': 'alias', 'value': v};
+    });
+    return result;
+  }
+
+  /// Merge into this instance all information from [other].
+  void addAll(NgMeta other) {
+    types.addAll(other.types);
+    aliases.addAll(other.aliases);
+  }
+
+  /// Returns the metadata for every type associated with the given [alias].
+  List<DirectiveMetadata> flatten(String alias) {
+    var result = [];
+    var seen = new Set();
+    helper(name) {
+      if (!seen.add(name)) {
+        logger.warning('Circular alias dependency for "$name".');
+        return;
+      }
+      if (types.containsKey(name)) {
+        result.add(types[name]);
+      } else if (aliases.containsKey(name)) {
+        aliases[name].forEach(helper);
+      } else {
+        logger.warning('Unknown alias: "$name".');
+      }
+    }
+    helper(alias);
+    return result;
+  }
+}

modules/angular2/src/transform/directive_metadata_extractor/extractor.dart

@@ -1,38 +1,49 @@
 library angular2.transform.directive_metadata_extractor.extractor;
 
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:analyzer/analyzer.dart';
-import 'package:angular2/src/render/api.dart';
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/logging.dart';
 import 'package:angular2/src/transform/common/names.dart';
 import 'package:angular2/src/transform/common/ng_deps.dart';
+import 'package:angular2/src/transform/common/ng_meta.dart';
 import 'package:barback/barback.dart';
 import 'package:code_transformers/assets.dart';
 
-/// Returns a map from a class name (that is, its `Identifier` stringified)
+/// Returns [NgMeta] associated with [entryPoint].
-/// to [DirectiveMetadata] for all `Directive`-annotated classes  visible
+///
-/// in a file importing `entryPoint`. That is, this includes all
+/// This includes entries for every `Directive`-annotated classes and
-/// `Directive` annotated classes in `entryPoint` and any assets which it
+/// constants that match the directive-aliases pattern, which are visible in a
-/// `export`s.
+/// file importing `entryPoint`.  That is, this includes all `Directive`
-/// Returns `null` if there are no `Directive`-annotated classes in
+/// annotated public classes in `entryPoint`, all `DirectiveAlias` annotated
-/// `entryPoint`.
+/// public variables, and any assets which it `export`s.  Returns an empty
-Future<Map<String, DirectiveMetadata>> extractDirectiveMetadata(
+/// [NgMeta] if there are no `Directive`-annotated classes in `entryPoint`.
-    AssetReader reader, AssetId entryPoint) async {
+Future<NgMeta> extractDirectiveMetadata(
+    AssetReader reader, AssetId entryPoint) {
   return _extractDirectiveMetadataRecursive(reader, entryPoint);
 }
 
 var _nullFuture = new Future.value(null);
 
-Future<Map<String, DirectiveMetadata>> _extractDirectiveMetadataRecursive(
+Future<NgMeta> _extractDirectiveMetadataRecursive(
     AssetReader reader, AssetId entryPoint) async {
-  if (!(await reader.hasInput(entryPoint))) return null;
+  var ngMeta = new NgMeta.empty();
+  if (!(await reader.hasInput(entryPoint))) return ngMeta;
 
   var ngDeps = await NgDeps.parse(reader, entryPoint);
-  var baseMap = _metadataMapFromNgDeps(ngDeps);
+  _extractMetadata(ngDeps, ngMeta);
 
-  return Future.wait(ngDeps.exports.map((export) {
+  var aliasesFile =
+      new AssetId(entryPoint.package, toAliasExtension(entryPoint.path));
+
+  if (await reader.hasInput(aliasesFile)) {
+    ngMeta.addAll(new NgMeta.fromJson(
+        JSON.decode(await reader.readAsString(aliasesFile))));
+  }
+
+  await Future.wait(ngDeps.exports.map((export) {
     var uri = stringLiteralToString(export.uri);
     if (uri.startsWith('dart:')) return _nullFuture;
 
@@ -41,25 +52,16 @@ Future<Map<String, DirectiveMetadata>> _extractDirectiveMetadataRecursive(
         errorOnAbsolute: false);
     if (assetId == entryPoint) return _nullFuture;
     return _extractDirectiveMetadataRecursive(reader, assetId)
-        .then((exportMap) {
+        .then(ngMeta.addAll);
-      if (exportMap != null) {
+  }));
-        if (baseMap == null) {
+  return ngMeta;
-          baseMap = exportMap;
-        } else {
-          baseMap.addAll(exportMap);
-        }
-      }
-    });
-  })).then((_) => baseMap);
 }
 
-Map<String, DirectiveMetadata> _metadataMapFromNgDeps(NgDeps ngDeps) {
+// TODO(sigmund): rather than having to parse it from generated code. we should
-  if (ngDeps == null || ngDeps.registeredTypes.isEmpty) return null;
+// be able to produce directly all information we need for ngMeta.
-  var retVal = <String, DirectiveMetadata>{};
+void _extractMetadata(NgDeps ngDeps, NgMeta ngMeta) {
-  ngDeps.registeredTypes.forEach((rType) {
+  if (ngDeps == null) return;
-    if (rType.directiveMetadata != null) {
+  ngDeps.registeredTypes.forEach((type) {
-      retVal['${rType.typeName}'] = rType.directiveMetadata;
+    ngMeta.types[type.typeName.name] = type.directiveMetadata;
-    }
   });
-  return retVal;
 }

modules/angular2/src/transform/directive_metadata_extractor/transformer.dart

@@ -3,7 +3,6 @@ library angular2.transform.directive_metadata_extractor.transformer;
 import 'dart:async';
 import 'dart:convert';
 
-import 'package:angular2/src/render/dom/convert.dart';
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/logging.dart' as log;
 import 'package:angular2/src/transform/common/names.dart';
@@ -29,14 +28,10 @@ class DirectiveMetadataExtractor extends Transformer {
       var reader = new AssetReader.fromTransform(transform);
       var fromAssetId = transform.primaryInput.id;
 
-      var metadataMap = await extractDirectiveMetadata(reader, fromAssetId);
+      var ngMeta = await extractDirectiveMetadata(reader, fromAssetId);
-      if (metadataMap != null) {
+      if (ngMeta != null && !ngMeta.isEmpty) {
-        var jsonMap = <String, Map>{};
-        metadataMap.forEach((k, v) {
-          jsonMap[k] = directiveMetadataToMap(v);
-        });
         transform.addOutput(new Asset.fromString(
-            _outputAssetId(fromAssetId), _encoder.convert(jsonMap)));
+            _outputAssetId(fromAssetId), _encoder.convert(ngMeta.toJson())));
       }
     }, errorMessage: 'Extracting ng metadata failed.');
   }

modules/angular2/src/transform/directive_processor/rewriter.dart

@@ -11,6 +11,7 @@ import 'package:angular2/src/transform/common/interface_matcher.dart';
 import 'package:angular2/src/transform/common/logging.dart';
 import 'package:angular2/src/transform/common/names.dart';
 import 'package:angular2/src/transform/common/xhr_impl.dart';
+import 'package:angular2/src/transform/common/ng_meta.dart';
 import 'package:barback/barback.dart' show AssetId;
 import 'package:path/path.dart' as path;
 
@@ -23,14 +24,19 @@ import 'visitors.dart';
 /// If no Angular 2 `Directive`s are found in `code`, returns the empty
 /// string unless `forceGenerate` is true, in which case an empty ngDeps
 /// file is created.
-Future<String> createNgDeps(
+Future<String> createNgDeps(AssetReader reader, AssetId assetId,
-    AssetReader reader, AssetId assetId, AnnotationMatcher annotationMatcher,
+    AnnotationMatcher annotationMatcher, NgMeta ngMeta,
     {bool inlineViews}) async {
   // TODO(kegluneq): Shortcut if we can determine that there are no
   // [Directive]s present, taking into account `export`s.
   var writer = new AsyncStringWriter();
-  var visitor = new CreateNgDepsVisitor(writer, assetId,
+  var visitor = new CreateNgDepsVisitor(
-      new XhrImpl(reader, assetId), annotationMatcher, _interfaceMatcher,
+      writer,
+      assetId,
+      new XhrImpl(reader, assetId),
+      annotationMatcher,
+      _interfaceMatcher,
+      ngMeta,
       inlineViews: inlineViews);
   var code = await reader.readAsString(assetId);
   parseCompilationUnit(code, name: assetId.path).accept(visitor);
@@ -49,10 +55,19 @@ InterfaceMatcher _interfaceMatcher = new InterfaceMatcher();
 /// associated .ng_deps.dart file.
 class CreateNgDepsVisitor extends Object with SimpleAstVisitor<Object> {
   final AsyncStringWriter writer;
+
+  /// Output ngMeta information about aliases.
+  // TODO(sigmund): add more to ngMeta. Currently this only contains aliasing
+  // information, but we could produce here all the metadata we need and avoid
+  // parsing the ngdeps files later.
+  final NgMeta ngMeta;
+
   /// Whether an Angular 2 `Injectable` has been found.
   bool _foundNgInjectable = false;
+
   /// Whether this library `imports` or `exports` any non-'dart:' libraries.
   bool _usesNonLangLibs = false;
+
   /// Whether we have written an import of base file
   /// (the file we are processing).
   bool _wroteBaseLibImport = false;
@@ -66,8 +81,13 @@ class CreateNgDepsVisitor extends Object with SimpleAstVisitor<Object> {
   /// The assetId for the file which we are parsing.
   final AssetId assetId;
 
-  CreateNgDepsVisitor(AsyncStringWriter writer, AssetId assetId, XHR xhr,
+  CreateNgDepsVisitor(
-      AnnotationMatcher annotationMatcher, InterfaceMatcher interfaceMatcher,
+      AsyncStringWriter writer,
+      AssetId assetId,
+      XHR xhr,
+      AnnotationMatcher annotationMatcher,
+      InterfaceMatcher interfaceMatcher,
+      this.ngMeta,
       {bool inlineViews})
       : writer = writer,
         _copyVisitor = new ToSourceVisitor(writer),
@@ -223,6 +243,29 @@ class CreateNgDepsVisitor extends Object with SimpleAstVisitor<Object> {
     return null;
   }
 
+  @override
+  Object visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
+    // We process any top-level declaration that fits the directive-alias
+    // declaration pattern. Ideally we would use an annotation on the field to
+    // help us filter out only what's needed, but unfortunately TypeScript
+    // doesn't support decorators on variable declarations (see
+    // angular/angular#1747 and angular/ts2dart#249 for context).
+    outer: for (var variable in node.variables.variables) {
+      var initializer = variable.initializer;
+      if (initializer != null && initializer is ListLiteral) {
+        var otherNames = [];
+        for (var exp in initializer.elements) {
+          // Only simple identifiers are supported for now.
+          // TODO(sigmund): add support for prefixes (see issue #3232).
+          if (exp is! SimpleIdentifier) continue outer;
+          otherNames.add(exp.name);
+        }
+        ngMeta.aliases[variable.name.name] = otherNames;
+      }
+    }
+    return null;
+  }
+
   Object _nodeToSource(AstNode node) {
     if (node == null) return null;
     return node.accept(_copyVisitor);

modules/angular2/src/transform/directive_processor/transformer.dart

@@ -1,11 +1,13 @@
 library angular2.transform.directive_processor.transformer;
 
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/logging.dart' as log;
 import 'package:angular2/src/transform/common/names.dart';
 import 'package:angular2/src/transform/common/options.dart';
+import 'package:angular2/src/transform/common/ng_meta.dart';
 import 'package:barback/barback.dart';
 
 import 'rewriter.dart';
@@ -32,8 +34,9 @@ class DirectiveProcessor extends Transformer {
     await log.initZoned(transform, () async {
       var asset = transform.primaryInput;
       var reader = new AssetReader.fromTransform(transform);
+      var ngMeta = new NgMeta.empty();
       var ngDepsSrc = await createNgDeps(
-          reader, asset.id, options.annotationMatcher,
+          reader, asset.id, options.annotationMatcher, ngMeta,
           inlineViews: options.inlineViews);
       if (ngDepsSrc != null && ngDepsSrc.isNotEmpty) {
         var ngDepsAssetId =
@@ -44,6 +47,12 @@ class DirectiveProcessor extends Transformer {
         }
         transform.addOutput(new Asset.fromString(ngDepsAssetId, ngDepsSrc));
       }
+      if (!ngMeta.isEmpty) {
+        var ngAliasesId =
+            transform.primaryInput.id.changeExtension(ALIAS_EXTENSION);
+        transform.addOutput(new Asset.fromString(ngAliasesId,
+            new JsonEncoder.withIndent("  ").convert(ngMeta.toJson())));
+      }
     }, errorMessage: 'Processing ng directives failed.');
   }
 }

modules/angular2/src/transform/template_compiler/view_definition_creator.dart

@@ -5,11 +5,11 @@ import 'dart:convert';
 
 import 'package:analyzer/analyzer.dart';
 import 'package:angular2/src/render/api.dart';
-import 'package:angular2/src/render/dom/convert.dart';
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/logging.dart';
 import 'package:angular2/src/transform/common/names.dart';
 import 'package:angular2/src/transform/common/ng_deps.dart';
+import 'package:angular2/src/transform/common/ng_meta.dart';
 import 'package:barback/barback.dart';
 import 'package:code_transformers/assets.dart';
 
@@ -60,18 +60,20 @@ class _ViewDefinitionCreator {
     var ngDeps = await ngDepsFuture;
 
     var retVal = <RegisteredType, ViewDefinitionEntry>{};
-    var visitor = new _TemplateExtractVisitor(await _createMetadataMap());
+    var visitor = new _TemplateExtractVisitor(await _extractNgMeta());
     ngDeps.registeredTypes.forEach((rType) {
       visitor.reset();
       rType.annotations.accept(visitor);
       if (visitor.viewDef != null) {
+        // Note: we use '' because the current file maps to the default prefix.
+        var ngMeta = visitor._metadataMap[''];
         var typeName = '${rType.typeName}';
         var hostMetadata = null;
-        if (visitor._metadataMap.containsKey(typeName)) {
+        if (ngMeta.types.containsKey(typeName)) {
-          hostMetadata = visitor._metadataMap[typeName];
+          hostMetadata = ngMeta.types[typeName];
           visitor.viewDef.componentId = hostMetadata.id;
         } else {
-          logger.error('Missing component "$typeName" in metadata map',
+          logger.warning('Missing component "$typeName" in metadata map',
               asset: entryPoint);
           visitor.viewDef.componentId = _getComponentId(entryPoint, typeName);
         }
@@ -91,7 +93,7 @@ class _ViewDefinitionCreator {
     var ngDeps = await ngDepsFuture;
 
     var importAssetToPrefix = <AssetId, String>{};
-    // Include the `.ng_meta.dart` file associated with `entryPoint`.
+    // Include the `.ng_meta.json` file associated with `entryPoint`.
     importAssetToPrefix[new AssetId(
         entryPoint.package, toMetaExtension(entryPoint.path))] = null;
 
@@ -137,24 +139,24 @@ class _ViewDefinitionCreator {
   ///   ...<any other entries>...
   /// }
   /// ```
-  Future<Map<String, DirectiveMetadata>> _createMetadataMap() async {
+  Future<Map<String, NgMeta>> _extractNgMeta() async {
     var importAssetToPrefix = await _createImportAssetToPrefixMap();
 
-    var retVal = <String, DirectiveMetadata>{};
+    var retVal = <String, NgMeta>{};
     for (var importAssetId in importAssetToPrefix.keys) {
+      var prefix = importAssetToPrefix[importAssetId];
+      if (prefix == null) prefix = '';
+      var ngMeta = retVal.putIfAbsent(prefix, () => new NgMeta.empty());
       var metaAssetId = new AssetId(
           importAssetId.package, toMetaExtension(importAssetId.path));
       if (await reader.hasInput(metaAssetId)) {
         try {
-          var json = await reader.readAsString(metaAssetId);
+          var json = JSON.decode(await reader.readAsString(metaAssetId));
-          var jsonMap = JSON.decode(json);
+          var newMetadata = new NgMeta.fromJson(json);
-          jsonMap.forEach((className, metaDataMap) {
+          newMetadata.types.forEach((className, metadata) {
-            var prefixStr = importAssetToPrefix[importAssetId];
+            metadata.id = _getComponentId(importAssetId, className);
-            var key = prefixStr != null ? '$prefixStr.$className' : className;
-            var value = directiveMetadataFromMap(metaDataMap)
-              ..id = _getComponentId(importAssetId, className);
-            retVal[key] = value;
           });
+          ngMeta.addAll(newMetadata);
         } catch (ex, stackTrace) {
           logger.warning('Failed to decode: $ex, $stackTrace',
               asset: metaAssetId);
@@ -169,7 +171,7 @@ class _ViewDefinitionCreator {
 /// [RegisterType] object and pulling out [ViewDefinition] information.
 class _TemplateExtractVisitor extends Object with RecursiveAstVisitor<Object> {
   ViewDefinition viewDef = null;
-  final Map<String, DirectiveMetadata> _metadataMap;
+  final Map<String, NgMeta> _metadataMap;
   final ConstantEvaluator _evaluator = new ConstantEvaluator();
 
   _TemplateExtractVisitor(this._metadataMap);
@@ -237,28 +239,35 @@ class _TemplateExtractVisitor extends Object with RecursiveAstVisitor<Object> {
     if (viewDef == null) return;
 
     if (node is! ListLiteral) {
-      logger.error(
+      logger.error('Angular 2 currently only supports list literals as values '
-          'Angular 2 currently only supports list literals as values for'
+          'for "directives". Source: $node');
-          ' "directives". Source: $node');
       return;
     }
     var directiveList = (node as ListLiteral);
     for (var node in directiveList.elements) {
-      if (node is! SimpleIdentifier && node is! PrefixedIdentifier) {
+      var ngMeta;
+      var name;
+      if (node is SimpleIdentifier) {
+        ngMeta = _metadataMap[''];
+        name = node.name;
+      } else if (node is PrefixedIdentifier) {
+        ngMeta = _metadataMap[node.prefix.name];
+        name = node.name;
+      } else {
         logger.error(
             'Angular 2 currently only supports simple and prefixed identifiers '
             'as values for "directives". Source: $node');
         return;
       }
-      var name = '$node';
+      if (ngMeta.types.containsKey(name)) {
-      if (_metadataMap.containsKey(name)) {
+        viewDef.directives.add(ngMeta.types[name]);
-        viewDef.directives.add(_metadataMap[name]);
+      } else if (ngMeta.aliases.containsKey(name)) {
+        viewDef.directives.addAll(ngMeta.flatten(name));
       } else {
-        logger.warning('Could not find Directive entry for $name. '
+        logger.warning('Could not find Directive entry for $node. '
-            'Please be aware that reusable, pre-defined lists of Directives '
+            'Please be aware that Dart transformers have limited support for '
-            '(aka "directive aliases") are not yet supported and will cause '
+            'reusable, pre-defined lists of Directives (aka '
-            'your application to misbehave. '
+            '"directive aliases"). See https://goo.gl/d8XPt0 for details.');
-            'See https://github.com/angular/angular/issues/1747 for details.');
       }
     }
   }

modules/angular2/test/transform/common/ng_meta_test.dart

@@ -0,0 +1,101 @@
+library angular2.test.transform.common.annotation_matcher_test;
+
+import 'package:angular2/src/render/api.dart';
+import 'package:angular2/src/transform/common/ng_meta.dart';
+import 'package:guinness/guinness.dart';
+
+main() => allTests();
+
+void allTests() {
+  var mockData = [
+    new DirectiveMetadata(id: 'm1'),
+    new DirectiveMetadata(id: 'm2'),
+    new DirectiveMetadata(id: 'm3'),
+    new DirectiveMetadata(id: 'm4')
+  ];
+
+  it('should allow empty data.', () {
+    var ngMeta = new NgMeta.empty();
+    expect(ngMeta.isEmpty).toBeTrue();
+  });
+
+  describe('serialization', () {
+    it('should parse empty data correctly.', () {
+      var ngMeta = new NgMeta.fromJson({});
+      expect(ngMeta.isEmpty).toBeTrue();
+    });
+
+    it('should be lossless', () {
+      var a = new NgMeta.empty();
+      a.types['T0'] = mockData[0];
+      a.types['T1'] = mockData[1];
+      a.types['T2'] = mockData[2];
+      a.types['T3'] = mockData[3];
+      a.aliases['a1'] = ['T1'];
+      a.aliases['a2'] = ['a1'];
+      a.aliases['a3'] = ['T3', 'a2'];
+      a.aliases['a4'] = ['a3', 'T3'];
+      _checkSimilar(a, new NgMeta.fromJson(a.toJson()));
+    });
+  });
+
+  describe('flatten', () {
+    it('should include recursive aliases.', () {
+      var a = new NgMeta.empty();
+      a.types['T0'] = mockData[0];
+      a.types['T1'] = mockData[1];
+      a.types['T2'] = mockData[2];
+      a.types['T3'] = mockData[3];
+      a.aliases['a1'] = ['T1'];
+      a.aliases['a2'] = ['a1'];
+      a.aliases['a3'] = ['T3', 'a2'];
+      a.aliases['a4'] = ['a3', 'T0'];
+      expect(a.flatten('a4')).toEqual([mockData[3], mockData[1], mockData[0]]);
+    });
+
+    it('should detect cycles.', () {
+      var a = new NgMeta.empty();
+      a.types['T0'] = mockData[0];
+      a.aliases['a1'] = ['T0', 'a1'];
+      a.aliases['a2'] = ['a1'];
+      expect(a.flatten('a1')).toEqual([mockData[0]]);
+    });
+  });
+
+  describe('merge', () {
+    it('should merge all types on addAll', () {
+      var a = new NgMeta.empty();
+      var b = new NgMeta.empty();
+      a.types['T0'] = mockData[0];
+      b.types['T1'] = mockData[1];
+      a.addAll(b);
+      expect(a.types).toContain('T1');
+      expect(a.types['T1']).toEqual(mockData[1]);
+    });
+
+    it('should merge all aliases on addAll', () {
+      var a = new NgMeta.empty();
+      var b = new NgMeta.empty();
+      a.aliases['a'] = ['x'];
+      b.aliases['b'] = ['y'];
+      a.addAll(b);
+      expect(a.aliases).toContain('b');
+      expect(a.aliases['b']).toEqual(['y']);
+    });
+  });
+}
+
+_checkSimilar(NgMeta a, NgMeta b) {
+  expect(a.types.length).toEqual(b.types.length);
+  expect(a.aliases.length).toEqual(b.aliases.length);
+  for (var k in a.types.keys) {
+    expect(b.types).toContain(k);
+    var at = a.types[k];
+    var bt = b.types[k];
+    expect(at.id).toEqual(bt.id);
+  }
+  for (var k in a.aliases.keys) {
+    expect(b.aliases).toContain(k);
+    expect(b.aliases[k]).toEqual(a.aliases[k]);
+  }
+}

modules/angular2/test/transform/directive_metadata_extractor/all_tests.dart

@@ -37,7 +37,10 @@ void allTests() {
     });
 
     it('should parse compile children values', () async {
-      var ngDeps = await NgDeps.parse(reader, new AssetId('a',
+      var ngDeps = await NgDeps.parse(
+          reader,
+          new AssetId(
+              'a',
               'directive_metadata_extractor/'
               'directive_metadata_files/compile_children.ng_deps.dart'));
       var it = ngDeps.registeredTypes.iterator;
@@ -122,71 +125,108 @@ void allTests() {
 
     it('should fail when a class is annotated with multiple Directives.',
         () async {
-      var ngDeps = await NgDeps.parse(reader, new AssetId('a',
+      var ngDeps = await NgDeps.parse(
+          reader,
+          new AssetId(
+              'a',
               'directive_metadata_extractor/'
               'directive_metadata_files/too_many_directives.ng_deps.dart'));
-      expect(() => ngDeps.registeredTypes.first.directiveMetadata).toThrowWith(
+      expect(() => ngDeps.registeredTypes.first.directiveMetadata)
-          anInstanceOf: PrintLoggerError);
+          .toThrowWith(anInstanceOf: PrintLoggerError);
     });
   });
 
   describe('extractMetadata', () {
     it('should generate `DirectiveMetadata` from .ng_deps.dart files.',
         () async {
-      var extracted = await extractDirectiveMetadata(reader, new AssetId(
+      var extracted = await extractDirectiveMetadata(
-          'a', 'directive_metadata_extractor/simple_files/foo.ng_deps.dart'));
+          reader,
-      expect(extracted).toContain('FooComponent');
+          new AssetId('a',
+              'directive_metadata_extractor/simple_files/foo.ng_deps.dart'));
+      expect(extracted.types).toContain('FooComponent');
 
-      var extractedMeta = extracted['FooComponent'];
+      var extractedMeta = extracted.types['FooComponent'];
       expect(extractedMeta.selector).toEqual('[foo]');
     });
 
-    it('should generate `DirectiveMetadata` from .ng_deps.dart files that use '
+    it(
-        'automatic adjacent string concatenation.', () async {
+        'should generate `DirectiveMetadata` from .ng_deps.dart files that use '
-      var extracted = await extractDirectiveMetadata(reader, new AssetId('a',
+        'automatic adjacent string concatenation.',
+        () async {
+      var extracted = await extractDirectiveMetadata(
+          reader,
+          new AssetId(
+              'a',
               'directive_metadata_extractor/adjacent_strings_files/'
               'foo.ng_deps.dart'));
-      expect(extracted).toContain('FooComponent');
+      expect(extracted.types).toContain('FooComponent');
 
-      var extractedMeta = extracted['FooComponent'];
+      var extractedMeta = extracted.types['FooComponent'];
       expect(extractedMeta.selector).toEqual('[foo]');
     });
 
     it('should include `DirectiveMetadata` from exported files.', () async {
-      var extracted = await extractDirectiveMetadata(reader, new AssetId(
+      var extracted = await extractDirectiveMetadata(
-          'a', 'directive_metadata_extractor/export_files/foo.ng_deps.dart'));
+          reader,
-      expect(extracted).toContain('FooComponent');
+          new AssetId('a',
-      expect(extracted).toContain('BarComponent');
+              'directive_metadata_extractor/export_files/foo.ng_deps.dart'));
+      expect(extracted.types).toContain('FooComponent');
+      expect(extracted.types).toContain('BarComponent');
 
-      expect(extracted['FooComponent'].selector).toEqual('[foo]');
+      expect(extracted.types['FooComponent'].selector).toEqual('[foo]');
-      expect(extracted['BarComponent'].selector).toEqual('[bar]');
+      expect(extracted.types['BarComponent'].selector).toEqual('[bar]');
     });
 
     it('should include `DirectiveMetadata` recursively from exported files.',
         () async {
-      var extracted = await extractDirectiveMetadata(reader, new AssetId('a',
+      var extracted = await extractDirectiveMetadata(
+          reader,
+          new AssetId('a',
               'directive_metadata_extractor/recursive_export_files/foo.ng_deps.dart'));
-      expect(extracted).toContain('FooComponent');
+      expect(extracted.types).toContain('FooComponent');
-      expect(extracted).toContain('BarComponent');
+      expect(extracted.types).toContain('BarComponent');
-      expect(extracted).toContain('BazComponent');
+      expect(extracted.types).toContain('BazComponent');
 
-      expect(extracted['FooComponent'].selector).toEqual('[foo]');
+      expect(extracted.types['FooComponent'].selector).toEqual('[foo]');
-      expect(extracted['BarComponent'].selector).toEqual('[bar]');
+      expect(extracted.types['BarComponent'].selector).toEqual('[bar]');
-      expect(extracted['BazComponent'].selector).toEqual('[baz]');
+      expect(extracted.types['BazComponent'].selector).toEqual('[baz]');
     });
 
-    it('should include `DirectiveMetadata` from exported files '
+    it(
-        'expressed as absolute uris', () async {
+        'should include `DirectiveMetadata` from exported files '
-      reader.addAsset(new AssetId('bar', 'lib/bar.ng_deps.dart'), readFile(
+        'expressed as absolute uris',
+        () async {
+      reader.addAsset(
+          new AssetId('bar', 'lib/bar.ng_deps.dart'),
+          readFile(
               'directive_metadata_extractor/absolute_export_files/bar.ng_deps.dart'));
 
-      var extracted = await extractDirectiveMetadata(reader, new AssetId('a',
+      var extracted = await extractDirectiveMetadata(
+          reader,
+          new AssetId('a',
               'directive_metadata_extractor/absolute_export_files/foo.ng_deps.dart'));
-      expect(extracted).toContain('FooComponent');
+      expect(extracted.types).toContain('FooComponent');
-      expect(extracted).toContain('BarComponent');
+      expect(extracted.types).toContain('BarComponent');
 
-      expect(extracted['FooComponent'].selector).toEqual('[foo]');
+      expect(extracted.types['FooComponent'].selector).toEqual('[foo]');
-      expect(extracted['BarComponent'].selector).toEqual('[bar]');
+      expect(extracted.types['BarComponent'].selector).toEqual('[bar]');
+    });
+
+    it('should include directive aliases', () async {
+      reader.addAsset(
+          new AssetId('bar', 'lib/bar.ng_deps.dart'),
+          readFile(
+              'directive_metadata_extractor/directive_aliases_files/bar.ng_deps.dart'));
+
+      var extracted = await extractDirectiveMetadata(
+          reader,
+          new AssetId('a',
+              'directive_metadata_extractor/directive_aliases_files/foo.ng_deps.dart'));
+      expect(extracted.aliases).toContain('alias1');
+      expect(extracted.aliases).toContain('alias2');
+      expect(extracted.aliases['alias1']).toContain('BarComponent');
+      expect(extracted.aliases['alias2']).toContain('FooComponent');
+      expect(extracted.aliases['alias2']).toContain('alias1');
     });
   });
 }

modules/angular2/test/transform/directive_metadata_extractor/directive_aliases_files/bar.aliases.json

@@ -0,0 +1,8 @@
+{
+  "alias1": {
+    "kind": "alias",
+    "value": [
+      "BarComponent"
+    ]
+  }
+}

modules/angular2/test/transform/directive_metadata_extractor/directive_aliases_files/bar.ng_deps.dart

@@ -0,0 +1,16 @@
+library foo.ng_deps.dart;
+
+import 'bar.dart';
+import 'package:angular2/src/core/annotations/annotations.dart';
+
+var _visited = false;
+void initReflector(reflector) {
+  if (_visited) return;
+  _visited = true;
+  reflector
+    ..registerType(BarComponent, {
+      'factory': () => new BarComponent(),
+      'parameters': const [],
+      'annotations': const [const Component(selector: '[bar]')]
+    });
+}

modules/angular2/test/transform/directive_metadata_extractor/directive_aliases_files/foo.aliases.json

@@ -0,0 +1,9 @@
+{
+  "alias2": {
+    "kind": "alias",
+    "value": [
+      "FooComponent",
+      "alias1"
+    ]
+  }
+}

modules/angular2/test/transform/directive_metadata_extractor/directive_aliases_files/foo.ng_deps.dart

@@ -0,0 +1,20 @@
+library foo.ng_deps.dart;
+
+import 'foo.dart';
+import 'package:angular2/src/core/annotations/annotations.dart';
+
+export 'bar.dart';
+import 'bar.ng_deps.dart' as i0;
+
+var _visited = false;
+void initReflector(reflector) {
+  if (_visited) return;
+  _visited = true;
+  reflector
+    ..registerType(FooComponent, {
+      'factory': () => new FooComponent(),
+      'parameters': const [],
+      'annotations': const [const Component(selector: '[foo]')]
+    });
+  i0.initReflector(reflector);
+}

modules/angular2/test/transform/directive_processor/all_tests.dart

@@ -1,10 +1,13 @@
 library angular2.test.transform.directive_processor.all_tests;
 
+import 'dart:convert';
+
 import 'package:barback/barback.dart';
 import 'package:angular2/src/transform/directive_processor/rewriter.dart';
 import 'package:angular2/src/transform/common/annotation_matcher.dart';
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/logging.dart' as log;
+import 'package:angular2/src/transform/common/ng_meta.dart';
 import 'package:code_transformers/messages/build_logger.dart';
 import 'package:dart_style/dart_style.dart';
 import 'package:guinness/guinness.dart';
@@ -18,17 +21,17 @@ main() {
 }
 
 void allTests() {
-  _testNgDeps('should preserve parameter annotations as const instances.',
+  _testProcessor('should preserve parameter annotations as const instances.',
       'parameter_metadata/soup.dart');
 
-  _testNgDeps('should recognize custom annotations with package: imports',
+  _testProcessor('should recognize custom annotations with package: imports',
       'custom_metadata/package_soup.dart',
       customDescriptors: [
     const ClassDescriptor('Soup', 'package:soup/soup.dart',
         superClass: 'Component'),
   ]);
 
-  _testNgDeps('should recognize custom annotations with relative imports',
+  _testProcessor('should recognize custom annotations with relative imports',
       'custom_metadata/relative_soup.dart',
       assetId: new AssetId('soup', 'lib/relative_soup.dart'),
       customDescriptors: [
@@ -36,27 +39,32 @@ void allTests() {
             superClass: 'Component'),
       ]);
 
-  _testNgDeps('Requires the specified import.', 'custom_metadata/bad_soup.dart',
+  _testProcessor(
+      'Requires the specified import.', 'custom_metadata/bad_soup.dart',
       customDescriptors: [
     const ClassDescriptor('Soup', 'package:soup/soup.dart',
         superClass: 'Component'),
   ]);
 
-  _testNgDeps(
+  _testProcessor(
       'should inline `templateUrl` values.', 'url_expression_files/hello.dart');
 
   var absoluteReader = new TestAssetReader();
-  absoluteReader.addAsset(new AssetId('other_package', 'lib/template.html'),
+  absoluteReader.addAsset(
+      new AssetId('other_package', 'lib/template.html'),
       readFile(
           'directive_processor/absolute_url_expression_files/template.html'));
-  absoluteReader.addAsset(new AssetId('other_package', 'lib/template.css'),
+  absoluteReader.addAsset(
+      new AssetId('other_package', 'lib/template.css'),
       readFile(
           'directive_processor/absolute_url_expression_files/template.css'));
-  _testNgDeps('should inline `templateUrl` and `styleUrls` values expressed as'
+  _testProcessor(
-      ' absolute urls.', 'absolute_url_expression_files/hello.dart',
+      'should inline `templateUrl` and `styleUrls` values expressed'
+      ' as absolute urls.',
+      'absolute_url_expression_files/hello.dart',
       reader: absoluteReader);
 
-  _testNgDeps(
+  _testProcessor(
       'should inline multiple `styleUrls` values expressed as absolute urls.',
       'multiple_style_urls_files/hello.dart');
 
@@ -64,40 +72,44 @@ void allTests() {
       readFile('directive_processor/multiple_style_urls_files/template.html'));
   absoluteReader.addAsset(new AssetId('a', 'lib/template.css'),
       readFile('directive_processor/multiple_style_urls_files/template.css'));
-  absoluteReader.addAsset(new AssetId('a', 'lib/template_other.css'), readFile(
+  absoluteReader.addAsset(
+      new AssetId('a', 'lib/template_other.css'),
+      readFile(
           'directive_processor/multiple_style_urls_files/template_other.css'));
-  _testNgDeps(
+  _testProcessor(
       'shouldn\'t inline multiple `styleUrls` values expressed as absolute '
-      'urls.', 'multiple_style_urls_not_inlined_files/hello.dart',
+      'urls.',
-      inlineViews: false, reader: absoluteReader);
+      'multiple_style_urls_not_inlined_files/hello.dart',
+      inlineViews: false,
+      reader: absoluteReader);
 
-  _testNgDeps('should inline `templateUrl`s expressed as adjacent strings.',
+  _testProcessor('should inline `templateUrl`s expressed as adjacent strings.',
       'split_url_expression_files/hello.dart');
 
-  _testNgDeps('should report implemented types as `interfaces`.',
+  _testProcessor('should report implemented types as `interfaces`.',
       'interfaces_files/soup.dart');
 
-  _testNgDeps('should not include transitively implemented types.',
+  _testProcessor('should not include transitively implemented types.',
       'interface_chain_files/soup.dart');
 
-  _testNgDeps('should not include superclasses in `interfaces`.',
+  _testProcessor('should not include superclasses in `interfaces`.',
       'superclass_files/soup.dart');
 
-  _testNgDeps(
+  _testProcessor(
       'should populate `lifecycle` when lifecycle interfaces are present.',
       'interface_lifecycle_files/soup.dart');
 
-  _testNgDeps('should populate multiple `lifecycle` values when necessary.',
+  _testProcessor('should populate multiple `lifecycle` values when necessary.',
       'multiple_interface_lifecycle_files/soup.dart');
 
-  _testNgDeps(
+  _testProcessor(
       'should populate `lifecycle` when lifecycle superclass is present.',
       'superclass_lifecycle_files/soup.dart');
 
-  _testNgDeps('should populate `lifecycle` with prefix when necessary.',
+  _testProcessor('should populate `lifecycle` with prefix when necessary.',
       'prefixed_interface_lifecycle_files/soup.dart');
 
-  _testNgDeps(
+  _testProcessor(
       'should not throw/hang on invalid urls', 'invalid_url_files/hello.dart',
       expectedLogs: [
     'ERROR: Uri /bad/absolute/url.html not supported from angular2|test/'
@@ -110,13 +122,20 @@ void allTests() {
         'test/transform/directive_processor/invalid_url_files/hello.dart'
   ]);
 
-  _testNgDeps('should find and register static functions.',
+  _testProcessor('should find and register static functions.',
       'static_function_files/hello.dart');
+
+  _testProcessor('should find direcive aliases patterns.',
+      'directive_aliases_files/hello.dart',
+      reader: absoluteReader);
 }
 
-void _testNgDeps(String name, String inputPath,
+void _testProcessor(String name, String inputPath,
-    {List<AnnotationDescriptor> customDescriptors: const [], AssetId assetId,
+    {List<AnnotationDescriptor> customDescriptors: const [],
-    AssetReader reader, List<String> expectedLogs, bool inlineViews: true,
+    AssetId assetId,
+    AssetReader reader,
+    List<String> expectedLogs,
+    bool inlineViews: true,
     bool isolate: false}) {
   var testFn = isolate ? iit : it;
   testFn(name, () async {
@@ -130,20 +149,33 @@ void _testNgDeps(String name, String inputPath,
         reader.addAsset(assetId, await reader.readAsString(inputId));
         inputId = assetId;
       }
-      var expectedPath = path.join(path.dirname(inputPath), 'expected',
+      var expectedNgDepsPath = path.join(path.dirname(inputPath), 'expected',
           path.basename(inputPath).replaceFirst('.dart', '.ng_deps.dart'));
-      var expectedId = _assetIdForPath(expectedPath);
+      var expectedNgDepsId = _assetIdForPath(expectedNgDepsPath);
+
+      var expectedAliasesPath = path.join(path.dirname(inputPath), 'expected',
+          path.basename(inputPath).replaceFirst('.dart', '.aliases.json'));
+      var expectedAliasesId = _assetIdForPath(expectedAliasesPath);
 
       var annotationMatcher = new AnnotationMatcher()
         ..addAll(customDescriptors);
-      var output = await createNgDeps(reader, inputId, annotationMatcher,
+      var ngMeta = new NgMeta.empty();
+      var output = await createNgDeps(
+          reader, inputId, annotationMatcher, ngMeta,
           inlineViews: inlineViews);
       if (output == null) {
-        expect(await reader.hasInput(expectedId)).toBeFalse();
+        expect(await reader.hasInput(expectedNgDepsId)).toBeFalse();
       } else {
-        var input = await reader.readAsString(expectedId);
+        var input = await reader.readAsString(expectedNgDepsId);
         expect(formatter.format(output)).toEqual(formatter.format(input));
       }
+      if (ngMeta.isEmpty) {
+        expect(await reader.hasInput(expectedAliasesId)).toBeFalse();
+      } else {
+        var expectedJson = await reader.readAsString(expectedAliasesId);
+        expect(new JsonEncoder.withIndent('  ').convert(ngMeta.toJson()))
+            .toEqual(expectedJson.trim());
+      }
     });
 
     if (expectedLogs != null) {

modules/angular2/test/transform/directive_processor/directive_aliases_files/a.dart

@@ -0,0 +1,3 @@
+class Bar {}
+
+const alias3 = const [Bar];

modules/angular2/test/transform/directive_processor/directive_aliases_files/b.dart

@@ -0,0 +1 @@
+class Baz {}

modules/angular2/test/transform/directive_processor/directive_aliases_files/expected/hello.aliases.json

@@ -0,0 +1,15 @@
+{
+  "alias1": {
+    "kind": "alias",
+    "value": [
+      "HelloCmp"
+    ]
+  },
+  "alias2": {
+    "kind": "alias",
+    "value": [
+      "HelloCmp",
+      "Foo"
+    ]
+  }
+}

modules/angular2/test/transform/directive_processor/directive_aliases_files/expected/hello.ng_deps.dart

@@ -0,0 +1,27 @@
+library examples.src.hello_world.absolute_url_expression_files.ng_deps.dart;
+
+import 'hello.dart';
+export 'hello.dart';
+import 'package:angular2/src/reflection/reflection.dart' as _ngRef;
+import 'package:angular2/angular2.dart'
+    show bootstrap, Component, Directive, View, NgElement;
+export 'a.dart' show alias3;
+import 'b.dart' as b;
+
+var _visited = false;
+void initReflector() {
+  if (_visited) return;
+  _visited = true;
+  _ngRef.reflector
+    ..registerType(HelloCmp, {
+      'factory': () => new HelloCmp(),
+      'parameters': const [],
+      'annotations': const [
+        const Component(selector: 'hello-app'),
+        const View(
+            template: r'''{{greeting}}''',
+            templateUrl: r'template.html',
+            styles: const [r'''.greeting { .color: blue; }''',])
+      ]
+    });
+}

modules/angular2/test/transform/directive_processor/directive_aliases_files/hello.dart

@@ -0,0 +1,20 @@
+library examples.src.hello_world.absolute_url_expression_files;
+
+import 'package:angular2/angular2.dart'
+    show bootstrap, Component, Directive, View, NgElement;
+export 'a.dart' show alias3;
+import 'b.dart' as b;
+
+@Component(selector: 'hello-app')
+@View(templateUrl: 'template.html', styleUrls: const ['template.css'])
+class HelloCmp {}
+
+class Foo {}
+
+// valid
+const alias1 = const [HelloCmp];
+// valid, even though it includes things that are not components
+const alias2 = const [HelloCmp, Foo];
+
+// Prefixed names are not supported
+const alias4 = const [b.Baz];

modules/angular2/test/transform/directive_processor/directive_aliases_files/template.css

@@ -0,0 +1 @@
+.greeting { .color: blue; }

modules/angular2/test/transform/directive_processor/directive_aliases_files/template.html

@@ -0,0 +1 @@
+{{greeting}}

modules/angular2/test/transform/integration/simple_annotation_files/expected/bar.ng_meta.json

@@ -1,5 +1,7 @@
 {
   "MyComponent": {
+    "kind": "type",
+    "value": {
       "id": "MyComponent",
       "selector": "[soup]",
       "compileChildren": true,
@@ -20,4 +22,5 @@
       "changeDetection": null,
       "version": 1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/all_tests.dart

@@ -36,6 +36,21 @@ void changeDetectorTests() {
     var output = await (process(new AssetId('a', inputPath)));
     expect(output).toContain('notifyOnBinding');
   });
+
+  it('should include directives mentioned in directive aliases.', () async {
+    // Input 2 is the same as input1, but contains the directive aliases
+    // inlined.
+    var input1Path =
+        'template_compiler/directive_aliases_files/hello1.ng_deps.dart';
+    var input2Path =
+        'template_compiler/directive_aliases_files/hello2.ng_deps.dart';
+    // Except for the directive argument in the View annotation, the generated
+    // change detectors are identical.
+    var output1 = (await process(new AssetId('a', input1Path))).replaceFirst(
+        'directives: const [alias1]', 'directives: const [GoodbyeCmp]');
+    var output2 = await process(new AssetId('a', input2Path));
+    _formatThenExpectEquals(output1, output2);
+  });
 }
 
 void noChangeDetectorTests() {

modules/angular2/test/transform/template_compiler/directive_aliases_files/hello1.ng_deps.dart

@@ -0,0 +1,28 @@
+library examples.hello_world.index_common_dart.ng_deps.dart;
+
+import 'hello.dart';
+import 'package:angular2/angular2.dart'
+    show bootstrap, Component, Directive, View, NgElement;
+
+var _visited = false;
+void initReflector(reflector) {
+  if (_visited) return;
+  _visited = true;
+  reflector
+    ..registerType(HelloCmp, {
+      'factory': () => new HelloCmp(),
+      'parameters': const [const []],
+      'annotations': const [
+        const Component(selector: 'hello-app'),
+        const View(template: 'goodbye-app', directives: const [alias1])
+      ]
+    })
+    ..registerType(GoodbyeCmp, {
+      'factory': () => new GoodbyeCmp(),
+      'parameters': const [const []],
+      'annotations': const [
+        const Component(selector: 'goodbye-app'),
+        const View(template: 'Goodbye')
+      ]
+    });
+}

modules/angular2/test/transform/template_compiler/directive_aliases_files/hello1.ng_meta.json

@@ -0,0 +1,35 @@
+{
+  "HelloCmp":
+  {
+    "kind": "type",
+    "value": {
+      "id":"HelloCmp",
+      "selector":"hello-app",
+      "compileChildren":true,
+      "host":{},
+      "properties":[],
+      "readAttributes":[],
+      "type":1,
+      "version":1
+    }
+  },
+  "GoodbyeCmp":{
+    "kind": "type",
+    "value": {
+      "id":"GoodbyeCmp",
+      "selector":"goodbye-app",
+      "compileChildren":true,
+      "host":{},
+      "properties":[],
+      "readAttributes":[],
+      "type":1,
+      "version":1
+    }
+  },
+  "aliases1":{
+    "kind": "alias",
+    "value": [
+      "GoodbyeCmp"
+    ]
+  }
+}

modules/angular2/test/transform/template_compiler/directive_aliases_files/hello2.ng_deps.dart

@@ -0,0 +1,28 @@
+library examples.hello_world.index_common_dart.ng_deps.dart;
+
+import 'hello.dart';
+import 'package:angular2/angular2.dart'
+    show bootstrap, Component, Directive, View, NgElement;
+
+var _visited = false;
+void initReflector(reflector) {
+  if (_visited) return;
+  _visited = true;
+  reflector
+    ..registerType(HelloCmp, {
+      'factory': () => new HelloCmp(),
+      'parameters': const [const []],
+      'annotations': const [
+        const Component(selector: 'hello-app'),
+        const View(template: 'goodbye-app', directives: const [GoodbyeCmp])
+      ]
+    })
+    ..registerType(GoodbyeCmp, {
+      'factory': () => new GoodbyeCmp(),
+      'parameters': const [const []],
+      'annotations': const [
+        const Component(selector: 'goodbye-app'),
+        const View(template: 'Goodbye')
+      ]
+    });
+}

modules/angular2/test/transform/template_compiler/directive_aliases_files/hello2.ng_meta.json

@@ -0,0 +1,29 @@
+{
+  "HelloCmp":
+  {
+    "kind": "type",
+    "value": {
+      "id":"HelloCmp",
+      "selector":"hello-app",
+      "compileChildren":true,
+      "host":{},
+      "properties":[],
+      "readAttributes":[],
+      "type":1,
+      "version":1
+    }
+  },
+  "GoodbyeCmp":{
+    "kind": "type",
+    "value": {
+      "id":"GoodbyeCmp",
+      "selector":"goodbye-app",
+      "compileChildren":true,
+      "host":{},
+      "properties":[],
+      "readAttributes":[],
+      "type":1,
+      "version":1
+    }
+  }
+}

modules/angular2/test/transform/template_compiler/duplicate_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -10,4 +12,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/inline_expression_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -10,4 +12,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/inline_method_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -10,4 +12,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/ng_for_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -10,4 +12,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/one_directive_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -9,8 +11,11 @@
       "readAttributes":[],
       "type":1,
       "version":1
+    }
   },
   "GoodbyeCmp":{
+    "kind": "type",
+    "value": {
       "id":"GoodbyeCmp",
       "selector":"goodbye-app",
       "compileChildren":true,
@@ -20,4 +25,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/url_expression_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -10,4 +12,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/url_method_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -10,4 +12,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/with_prefix_files/goodbye.ng_meta.json

@@ -1,5 +1,7 @@
 {
   "GoodbyeCmp":{
+    "kind": "type",
+    "value": {
       "id":"GoodbyeCmp",
       "selector":"goodbye-app",
       "compileChildren":true,
@@ -9,4 +11,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/with_prefix_files/hello.ng_meta.json

@@ -1,6 +1,8 @@
 {
   "HelloCmp":
   {
+    "kind": "type",
+    "value": {
       "id":"HelloCmp",
       "selector":"hello-app",
       "compileChildren":true,
@@ -10,4 +12,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/template_compiler/with_prefix_files/ng2_prefix.ng_meta.json

@@ -1,5 +1,7 @@
 {
   "MyApp":{
+    "kind": "type",
+    "value": {
       "id":"MyApp",
       "selector":"my-app",
       "compileChildren":true,
@@ -9,4 +11,5 @@
       "type":1,
       "version":1
     }
+  }
 }

modules/angular2/test/transform/transform.server.spec.dart

@@ -5,6 +5,7 @@ import 'package:unittest/unittest.dart' hide expect;
 import 'package:unittest/vm_config.dart';
 
 import 'common/async_string_writer_tests.dart' as asyncStringWriter;
+import 'common/ng_meta_test.dart' as ngMetaTest;
 import 'bind_generator/all_tests.dart' as bindGenerator;
 import 'deferred_rewriter/all_tests.dart' as deferredRewriter;
 import 'directive_linker/all_tests.dart' as directiveLinker;
@@ -17,6 +18,7 @@ import 'template_compiler/all_tests.dart' as templateCompiler;
 main() {
   useVMConfiguration();
   describe('AsyncStringWriter', asyncStringWriter.allTests);
+  describe('NgMeta', ngMetaTest.allTests);
   describe('Bind Generator', bindGenerator.allTests);
   describe('Directive Linker', directiveLinker.allTests);
   describe('Directive Metadata Extractor', directiveMeta.allTests);

modules/examples/pubspec.yaml

@@ -30,13 +30,10 @@ transformers:
         - web/src/key_events/index.dart
         - web/src/sourcemap/index.dart
         - web/src/todo/index.dart
-        # These entrypoints are disabled until nested-directives are supported
+        - web/src/model_driven_forms/index.dart
-        # by transformers (issue #1747):
+        - web/src/order_management/index.dart
-        # web/src/model_driven_forms/index.dart
+        - web/src/person_management/index.dart
-        # web/src/order_management/index.dart
+        - web/src/template_driven_forms/index.dart
-        # web/src/person_management/index.dart
-        # web/src/template_driven_forms/index.dart
-        #
         # These entrypoints are disabled until cross-package urls are working (issue #2982)
         # - web/src/material/button/index.dart
         # - web/src/material/checkbox/index.dart
@@ -57,13 +54,10 @@ transformers:
         - web/src/key_events/index.dart
         - web/src/sourcemap/index.dart
         - web/src/todo/index.dart
-        # These entrypoints are disabled until nested-directives are supported
+        - web/src/model_driven_forms/index.dart
-        # by transformers (issue #1747):
+        - web/src/order_management/index.dart
-        # web/src/model_driven_forms/index.dart
+        - web/src/person_management/index.dart
-        # web/src/order_management/index.dart
+        - web/src/template_driven_forms/index.dart
-        # web/src/person_management/index.dart
-        # web/src/template_driven_forms/index.dart
-        #
         # These entrypoints are disabled until cross-package urls are working (issue #2982)
         # - web/src/material/button/index.dart
         # - web/src/material/checkbox/index.dart

modules/examples/src/order_management/index.ts

@@ -13,6 +13,8 @@ import {
   EventEmitter
 } from 'angular2/bootstrap';
 
+import {Injectable} from 'angular2/di';
+
 import {formDirectives} from 'angular2/forms';
 
 import {ListWrapper} from 'angular2/src/facade/collection';
@@ -44,6 +46,7 @@ class Order {
 // ---- services
 
 var _nextId = 1000;
+@Injectable()
 class DataService {
   orderItems: OrderItem[];
   orders: Order[];

modules/examples/src/person_management/index.ts

@@ -12,6 +12,8 @@ import {
   Binding
 } from 'angular2/bootstrap';
 
+import {Injectable} from 'angular2/di';
+
 import {formDirectives} from 'angular2/forms';
 
 import {RegExpWrapper, print, isPresent, CONST_EXPR} from 'angular2/src/facade/lang';
@@ -50,6 +52,7 @@ class Person {
 
 // ---- services
 
+@Injectable()
 class DataService {
   currentPerson: Person;
   persons: Person[];

tools/broccoli/trees/dart_tree.ts

@@ -51,7 +51,8 @@ function getSourceTree() {
     translateBuiltins: true,
   });
   // Native sources, dart only examples, etc.
-  var dartSrcs = modulesFunnel(['**/*.dart', '**/*.ng_meta.json', '**/css/**']);
+  var dartSrcs =
+      modulesFunnel(['**/*.dart', '**/*.ng_meta.json', '**/*.aliases.json', '**/css/**']);
   return mergeTrees([transpiled, dartSrcs]);
 }