feat(dart/transform): Add a `.ng_deps.dart` file parser.

Create a common, reusable `.ng_deps.dart` file parser. All future transformer
phases build on the information in `.ng_deps.dart` files.

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

@@ -0,0 +1,26 @@
+library angular2.src.transform.common.asset_reader;
+
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:barback/barback.dart';
+
+abstract class AssetReader {
+  Future<String> readAsString(AssetId id, {Encoding encoding});
+  Future<bool> hasInput(AssetId id);
+
+  /// Creates an [AssetReader] using the `transform`, which should be a
+  /// [Transform] or [AggregateTransform].
+  factory AssetReader.fromTransform(dynamic transform) =>
+      new _TransformAssetReader(transform);
+}
+
+class _TransformAssetReader implements AssetReader {
+  final dynamic t;
+  _TransformAssetReader(this.t);
+
+  Future<String> readAsString(AssetId id, {Encoding encoding}) =>
+      t.readInputAsString(id, encoding: encoding);
+
+  Future<bool> hasInput(AssetId id) => t.hasInput(id);
+}

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

@@ -0,0 +1,103 @@
+library angular2.src.transform.common.parser;
+
+import 'dart:async';
+
+import 'package:analyzer/analyzer.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:barback/barback.dart';
+import 'package:code_transformers/assets.dart';
+
+import 'registered_type.dart';
+
+export 'registered_type.dart';
+
+class Parser {
+  final AssetReader _reader;
+  final _ParseNgDepsVisitor _visitor = new _ParseNgDepsVisitor();
+
+  Parser(AssetReader this._reader);
+
+  Future<List<NgDeps>> parseRecursive(AssetId id) async {
+    return _recurse(id);
+  }
+
+  Future<NgDeps> parse(AssetId id) async {
+    if (!(await _reader.hasInput(id))) return null;
+    var ngDeps = new NgDeps(await _reader.readAsString(id));
+    _visitor.ngDeps = ngDeps;
+    parseCompilationUnit(ngDeps.code, name: id.path).accept(_visitor);
+    return ngDeps;
+  }
+
+  /// Parses the `.ngDeps.dart` file represented by [id] into an [NgDeps]
+  /// object. All `.ngDeps.dart` files imported by [id] are then parsed. The
+  /// results are added to [allDeps].
+  Future<List<NgDeps>> _recurse(AssetId id,
+      [List<NgDeps> allDeps, Set<AssetId> seen]) async {
+    if (seen == null) seen = new Set<AssetId>();
+    if (seen.contains(id)) return;
+    seen.add(id);
+
+    if (allDeps == null) allDeps = [];
+    var ngDeps = await parse(id);
+    allDeps.add(ngDeps);
+
+    var toWait = [];
+    ngDeps.imports.forEach((ImportDirective node) {
+      var uri = stringLiteralToString(node.uri);
+      if (uri.endsWith(DEPS_EXTENSION)) {
+        var importId = uriToAssetId(id, uri, logger, null);
+        toWait.add(_recurse(importId, allDeps, seen));
+      }
+    });
+    return Future.wait(toWait).then((_) => allDeps);
+  }
+}
+
+class NgDeps {
+  final String code;
+  final List<ImportDirective> imports = [];
+  final List<ExportDirective> exports = [];
+  final List<RegisteredType> registeredTypes = [];
+  FunctionDeclaration setupMethod;
+
+  NgDeps(this.code);
+}
+
+class _ParseNgDepsVisitor extends Object with RecursiveAstVisitor<Object> {
+  NgDeps ngDeps = null;
+  _RegisteredTypeBuilder current = null;
+
+  @override
+  Object visitImportDirective(ImportDirective node) {
+    ngDeps.imports.add(node);
+    return super.visitImportDirective(node);
+  }
+
+  @override
+  Object visitExportDirective(ExportDirective node) {
+    ngDeps.exports.add(node);
+    return super.visitExportDirective(node);
+  }
+
+  @override
+  Object visitFunctionDeclaration(FunctionDeclaration node) {
+    if ('${node.name}' == SETUP_METHOD_NAME) {
+      ngDeps.setupMethod = node;
+    }
+    return super.visitFunctionDeclaration(node);
+  }
+
+  @override
+  Object visitMethodInvocation(MethodInvocation node) {
+    var isRegisterType = '${node.methodName}' == REGISTER_TYPE_METHOD_NAME;
+
+    if (isRegisterType) {
+      ngDeps.registeredTypes.add(new RegisteredType.fromMethodInvocation(node));
+    }
+
+    return super.visitMethodInvocation(node);
+  }
+}

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

@@ -0,0 +1,65 @@
+library angular2.src.transform.common.registered_type;
+
+import 'package:analyzer/analyzer.dart';
+import 'package:angular2/src/transform/common/names.dart';
+
+/// Represents a call to `Reflector#registerType` generated by
+/// `DirectiveProcessor`.
+class RegisteredType {
+  final Identifier typeName;
+  final MethodInvocation registerMethod;
+  final Expression factory;
+  final Expression parameters;
+  final Expression annotations;
+
+  RegisteredType._(this.typeName, this.registerMethod, this.factory,
+      this.parameters, this.annotations);
+
+  /// Creates a [RegisteredType] given a [MethodInvocation] node representing
+  /// a call to `registerType`.
+  factory RegisteredType.fromMethodInvocation(MethodInvocation registerMethod) {
+    var visitor = new _ParseRegisterTypeVisitor();
+    registerMethod.accept(visitor);
+    return new RegisteredType._(visitor.typeName, registerMethod,
+        visitor.factory, visitor.parameters, visitor.annotations);
+  }
+}
+
+class _ParseRegisterTypeVisitor extends Object
+    with RecursiveAstVisitor<Object> {
+  Identifier typeName;
+  Expression factory;
+  Expression parameters;
+  Expression annotations;
+
+  @override
+  Object visitMethodInvocation(MethodInvocation node) {
+    assert('${node.methodName}' == REGISTER_TYPE_METHOD_NAME);
+
+    // The first argument to a `registerType` call is the type.
+    typeName = node.argumentList.arguments[0] is Identifier
+        ? node.argumentList.arguments[0]
+        : null;
+    return super.visitMethodInvocation(node);
+  }
+
+  @override
+  Object visitMapLiteralEntry(MapLiteralEntry node) {
+    if (node.key is StringLiteral) {
+      var key = stringLiteralToString(node.key);
+      switch (key) {
+        case 'annotations':
+          annotations = node.value;
+          break;
+        case 'factory':
+          factory = node.value;
+          break;
+        case 'parameters':
+          parameters = node.value;
+          break;
+      }
+    }
+    // Do not need to descend any further.
+    return null;
+  }
+}

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

@@ -1,7 +1,11 @@
 library angular2.test.transform.common.read_file;
 
+import 'dart:async';
 import 'dart:io';
 
+import 'package:angular2/src/transform/common/asset_reader.dart';
+import 'package:barback/barback.dart';
+
 /// Smooths over differences in CWD between IDEs and running tests in Travis.
 String readFile(String path) {
   for (var myPath in [path, 'test/transform/${path}']) {
@@ -12,3 +16,17 @@ String readFile(String path) {
   }
   return null;
 }
+
+class TestAssetReader implements AssetReader {
+  Future<String> readAsString(AssetId id, {Encoding encoding}) =>
+      new Future.value(readFile(id.path));
+
+  Future<bool> hasInput(AssetId id) {
+    var exists = false;
+    for (var myPath in [id.path, 'test/transform/${id.path}']) {
+      var file = new File(myPath);
+      exists = exists || file.existsSync();
+    }
+    return new Future.value(exists);
+  }
+}