Allow multiple-entry libraries in code_transformers

pkg/code_transformers/lib/src/resolver.dart

 // Copyright (c) 2014, 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 code_transformer.src.resolver;
 
 import 'dart:async';
 
 import 'package:analyzer/src/generated/element.dart';
 import 'package:barback/barback.dart';
 import 'package:source_maps/refactor.dart';
 import 'package:source_maps/span.dart' show SourceFile, Span;
 
 
 /// Class for working with a barback based resolved AST.
 abstract class Resolver {
-  /// The Dart entry point file where parsing begins.
-  AssetId get entryPoint;
-
-  /// Update the status of all the sources referenced by the entryPoint and
-  /// update the resolved library.
+  /// Update the status of all the sources referenced by the entry points and
+  /// update the resolved library. If [entryPoints] is omitted, the primary
+  /// asset of [transform] is used as the only entry point.
   ///
   /// [release] must be called when done handling this Resolver to allow it
   /// to be used by later phases.
-  Future<Resolver> resolve(Transform transform);
+  Future<Resolver> resolve(Transform transform, [List<AssetId> entryPoints]);
 
   /// Release this resolver so it can be updated by following transforms.
   void release();
 
-  /// Gets the resolved Dart library for the entry asset, or null if
-  /// the AST has not been resolved.
+  /// Gets the resolved Dart library for an asset, or null if the AST has not
+  /// been resolved.
   ///
   /// If the AST has not been resolved then this normally means that the
   /// transformer hosting this needs to be in an earlier phase.
-  LibraryElement get entryLibrary;
+  LibraryElement getLibrary(AssetId assetId);
 
   /// Gets all libraries accessible from the entry point, recursively.
   ///
   /// This includes all Dart SDK libraries as well.
   Iterable<LibraryElement> get libraries;
 
   /// Finds the first library identified by [libraryName], or null if no
   /// library can be found.
   LibraryElement getLibraryByName(String libraryName);
 
@@ skipping 30 matching lines @@
   /// from [from] (if provided).
   Uri getImportUri(LibraryElement lib, {AssetId from});
 
   /// Get the asset ID of the file containing the asset.
   AssetId getSourceAssetId(Element element);
 
   /// Get the source span where the specified element was defined or null if
   /// the element came from the Dart SDK.
   Span getSourceSpan(Element element);
 
+  /// Get a [SourceFile] with the contents of the file that defines [element],
+  /// or null if the element came from the Dart SDK.
+  SourceFile getSourceFile(Element element);
+
   /// Creates a text edit transaction for the given element if it is able
   /// to be edited, returns null otherwise.
   ///
   /// The transaction contains the entire text of the source file where the
   /// element originated. If the element was from a library part then the
   /// source file is the part file rather than the library.
   TextEditTransaction createTextEditTransaction(Element element);
 }