Major refactor of the transformer, added an `InitializePlugin` class which allows you to hook direc…

lib/plugin_transformer.dart

-// Copyright (c) 2015, 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 initialize.plugin_transformer;
-
-import 'dart:async';
-import 'package:analyzer/analyzer.dart';
-import 'package:barback/barback.dart';
-import 'package:source_maps/refactor.dart';
-import 'package:source_span/source_span.dart';
-
-/// Abstract transformer which will call [initEntry] for every [InitEntry]
-/// expression found in the bootstrap file. This is used to centralize logic
-/// for initializers which want to do something special at transform time.
-abstract class InitializePluginTransformer extends AggregateTransformer {
-  // Path to the bootstrap file created by the initialize transformer.
-  final String _bootstrapFile;
-
-  // All the extra assets that were found, if child classes override
-  // classifyPrimary this lets them get at the other assets easily.
-  final allAssets = <Asset>[];
-
-  TransformLogger _logger;
-
-  InitializePluginTransformer(this._bootstrapFile);
-
-  classifyPrimary(AssetId id) =>
-      _bootstrapFile == id.path ? _bootstrapFile : null;
-
-  Future apply(AggregateTransform transform) {
-    _logger = transform.logger;
-    var done = new Completer();
-    var listener = transform.primaryInputs.listen((Asset asset) {
-      allAssets.add(asset);
-      var id = asset.id;
-      if (id.path != _bootstrapFile) return;
-      // Calls initEntry for each InitEntry expression.
-      asset.readAsString().then((dartCode) {
-        var url = id.path.startsWith('lib/')
-            ? 'package:${id.package}/${id.path.substring(4)}'
-            : id.path;
-        var source = new SourceFile(dartCode, url: url);
-        var transaction = new TextEditTransaction(dartCode, source);
-        (parseCompilationUnit(dartCode,
-                    suppressErrors: true) as dynamic).declarations.firstWhere(
-                (d) => d.name.toString() ==
-                    'main').functionExpression.body.block.statements.firstWhere(
-            (statement) {
-          return statement.expression.target.toString() == 'initializers' &&
-              statement.expression.methodName.toString() == 'addAll';
-        }).expression.argumentList.arguments[0].elements
-            .where((arg) => arg is InstanceCreationExpression)
-            .forEach((e) => initEntry(e, transaction));
-
-        // Apply any transformations.
-        if (!transaction.hasEdits) {
-          transform.addOutput(asset);
-        } else {
-          var printer = transaction.commit();
-          printer.build(url);
-          transform.addOutput(new Asset.fromString(id, printer.text));
-        }
-        done.complete();
-      });
-    });
-
-    // Make sure all the assets are read before returning.
-    return Future.wait([listener.asFuture(), done.future]);
-  }
-
-  /// Gets called once for each generated [InitEntry] expression in the
-  /// bootstrap file. A [TextEditTransaction] is supplied so that the user can
-  /// modify the expression however they see fit.
-  void initEntry(
-      InstanceCreationExpression expression, TextEditTransaction transaction);
-
-  /// Convenience method to delete an Initializer expression completely.
-  void removeInitializer(
-      InstanceCreationExpression expression, TextEditTransaction transaction) {
-    // Delete the entire line.
-    var line = transaction.file.getLine(expression.offset);
-    transaction.edit(transaction.file.getOffset(line),
-        transaction.file.getOffset(line + 1), '');
-  }
-}