Remove mirrors imports in transformed code.

lib/js.dart

@@ -8,11 +8,6 @@
  */
 library js;
 
-export 'dart:js' show JsObject;
-
-// this must be a package import due to dartbug.com/20666
-export 'package:js/src/js_impl.dart' show JsInterface;
-export 'package:js/src/metadata.dart';
-import 'package:js/src/mirrors.dart' as impl show initializeJavaScript;
-
-void initializeJavaScript() => impl.initializeJavaScript();
+// js.dart is just an alias for mirrors.dart at runtime. The transformer
+// replaces this import of js.dart with src/static.dart.
+export 'package:js/src/mirrors.dart';

lib/src/js_impl.dart

@@ -11,24 +11,20 @@ library js.impl;
 import 'dart:js';
 export 'dart:js' show context, JsObject;
 
-// TODO(justinfagnani): replace this import with a static impl
-// during transformation
-import 'package:js/src/mirrors.dart';
-import 'package:js/src/mirrors.dart' as mirrors show isGlobal;
-
 const DART_OBJECT_PROPERTY = '__dart_object__';
 
 /**
  * The base class of Dart interfaces for JavaScript objects.
  */
-abstract class JsInterface extends JsInterfaceImpl {
+abstract class JsInterface {
 
   final JsObject _jsObject;
 
-  factory JsInterface(Type type, [Iterable args]) =>
-      new JsInterfaceImpl(type, args);
+  factory JsInterface(Type type, [Iterable args]) {
+    throw new StateError('JsInterface should never be called');
+  }
 
-  JsInterface.created(JsObject o) : _jsObject = o, super.created() {
+  JsInterface.created(JsObject o) : _jsObject = o {
     // since multiple Dart objects of different classes may represent
     // the global name space, we don't store a reference
     if (!isGlobal(this)) {
@@ -41,10 +37,12 @@ abstract class JsInterface extends JsInterfaceImpl {
 
 }
 
-// This only works in JS because we're still pulling mirrors. We need to
-// generate metadata about which classes are global when we transform out
-// mirrors.
-bool isGlobal(JsInterface o) => mirrors.isGlobal(o);
+/**
+ * Marker interface for global objects.
+ */
+abstract class JsGlobal {}
+
+bool isGlobal(JsInterface o) => o is JsGlobal;
 
 /**
  * Converts a Dart object to a [JsObject] (or supported primitive) for sending

lib/src/mirrors.dart

@@ -12,11 +12,17 @@ import 'dart:js' as js;
 import 'dart:mirrors';
 import 'dart:mirrors' as mirrors;
 
-import 'package:js/js.dart';
 import 'package:js/src/metadata.dart';
 import 'package:js/src/js_elements.dart';
 import 'package:js/src/js_impl.dart' as jsi;
 import 'package:js/src/js_impl.dart';
+
+// This is the public interface of js.dart
+// The exports must match those in static.dart
+export 'package:js/src/js_impl.dart' hide JsInterface;
+export 'dart:js' show JsObject;
+export 'package:js/src/metadata.dart';
+
 import 'package:quiver/mirrors.dart';
 
 final _dart = js.context['dart'];
@@ -270,17 +276,11 @@ DartType _getType(ParameterMirror p) => new DartType(_getName(p.type));
 
 final Expando _globals = new Expando();
 
-bool isGlobal(JsInterface o) {
-  var classMirror = reflect(o).type;
-  var jsProxyAnnotation = _getJsProxyAnnotation(classMirror);
-  return jsProxyAnnotation.global;
-}
-
-class JsInterfaceImpl {
+class JsInterface extends jsi.JsInterface {
 
-  JsInterfaceImpl.created();
+  JsInterface.created(JsObject o) : super.created(o);
 
-  factory JsInterfaceImpl(Type type, Iterable args) {
+  factory JsInterface(Type type, Iterable args) {
     if (_globals[type] != null) {
       return _globals[type];
     }

lib/src/static.dart

@@ -0,0 +1,15 @@
+library js.static;
+
+// This is the public interface of js.dart
+// The exports must match those in static.dart
+export 'package:js/src/js_impl.dart';
+export 'dart:js' show JsObject;
+export 'package:js/src/metadata.dart';
+
+void initializeJavaScript() {
+  throw new StateError("Non-transformed initialization is being called. "
+      "You are using js.dart in deployed mode, but you probably haven't "
+      "configured the initializer transformer, or you are calling "
+      "initializeJavaScript() somewhere other than main(). "
+      "Try adding '- js/initializer' to your applications transformers.");
+}

lib/src/transformer/js_proxy_generator.dart

@@ -44,10 +44,7 @@ class JsProxyGenerator {
     this.transaction)
       : library = library,
         jsLibrary = jsLibrary,
-        jsInterfaceClass = jsLibrary
-            .exportedLibraries
-            .singleWhere((l) => l.name == 'js.impl')
-            .getType('JsInterface'),
+        jsInterfaceClass = getImplLib(jsLibrary).getType('JsInterface'),
         jsProxyClass = jsMetadataLibrary.getType('JsProxy'),
         exportClass = jsMetadataLibrary.getType('Export'),
         noExportClass = jsMetadataLibrary.getType('NoExport'),

lib/src/transformer/remove_mirrors_transformer.dart

@@ -0,0 +1,32 @@
+// 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 js.transformer.remove_mirrors_transformer;
+
+import 'package:barback/barback.dart' show Asset, AssetId, BarbackSettings,
+    Transform, Transformer;
+import 'package:logging/logging.dart' show Logger;
+
+final _logger = new Logger('js.transformer.remove_mirrors_transformer');
+
+class RemoveMirrorsTransformer extends Transformer {
+
+  RemoveMirrorsTransformer();
+
+  RemoveMirrorsTransformer.asPlugin(BarbackSettings settings);
+
+  @override
+  isPrimary(AssetId id) => id.package == 'js' && id.path == 'lib/js.dart';
+
+  @override
+  apply(Transform transform) {
+    var input = transform.primaryInput;
+    return input.readAsString().then((source) {
+      var newSource = source.replaceAll(
+          "export 'package:js/src/mirrors.dart';",
+          "export 'package:js/src/static.dart';");
+      transform.addOutput(new Asset.fromString(input.id, newSource));
+    });
+  }
+}

lib/src/transformer/scanning_visitor.dart

@@ -48,10 +48,7 @@ class ScanningVisitor extends RecursiveElementVisitor {
       LibraryElement jsMetadataLibrary,
       this.entryLibrary)
       : this.jsLibrary = jsLibrary,
-        jsInterfaceClass = jsLibrary
-            .exportedLibraries
-            .singleWhere((l) => l.name == 'js.impl')
-            .getType('JsInterface'),
+        jsInterfaceClass = getImplLib(jsLibrary).getType('JsInterface'),
         jsProxyClass = jsMetadataLibrary.getType('JsProxy'),
         exportClass = jsMetadataLibrary.getType('Export'),
         noExportClass = jsMetadataLibrary.getType('NoExport') {

lib/src/transformer/utils.dart

@@ -14,6 +14,20 @@ import 'package:quiver/iterables.dart' show max;
 const String DART_INITIALIZER_SUFFIX = "__init_js__.dart";
 const String JS_INITIALIZER_SUFFIX = "__init_js__.js";
 
+LibraryElement getEnvironementImplLib(LibraryElement jsLib) =>
+    jsLib.exportedLibraries
+        .singleWhere((l) => l.name == 'js.mirrors' || l.name == 'js.static');
+
+LibraryElement getMetadataLib(LibraryElement jsLib) =>
+    getEnvironementImplLib(jsLib)
+        .exportedLibraries
+        .singleWhere((l) => l.name == 'js.metadata');
+
+LibraryElement getImplLib(LibraryElement jsLib) =>
+    getEnvironementImplLib(jsLib)
+        .exportedLibraries
+        .singleWhere((l) => l.name == 'js.impl');
+
 JsProxy getProxyAnnotation(ClassElement interface, ClassElement jsProxyClass) {
   var node = interface.node;
   for (Annotation a in node.metadata) {

pubspec.yaml

@@ -17,3 +17,5 @@ dependencies:
 dev_dependencies:
   path: '>=1.0.0 <2.0.0'
   unittest: '>=0.9.0 <0.12.0'
+transformers:
+- js/src/transformer/remove_mirrors_transformer

test/transformer/dart_initializer_generator_test.dart

@@ -9,6 +9,7 @@ import 'package:analyzer/src/generated/engine.dart';
 import 'package:barback/barback.dart';
 import 'package:js/src/transformer/dart_initializer_generator.dart';
 import 'package:js/src/transformer/scanning_visitor.dart';
+import 'package:js/src/transformer/utils.dart';
 import 'package:source_maps/refactor.dart';
 import 'package:source_span/source_span.dart';
 import 'package:unittest/unittest.dart';
@@ -29,9 +30,7 @@ main() {
       var analyserInfo = initAnalyzer();
       testLib = analyserInfo.testLib;
       jsLib = analyserInfo.jsLib;
-      jsMetadataLib = jsLib
-          .exportedLibraries
-          .singleWhere((l) => l.name == 'js.metadata');
+      jsMetadataLib = getMetadataLib(jsLib);
       testLibSource = analyserInfo.context.getContents(testLib.source).data;
     });
 

test/transformer/entry_point_transformer_test.dart

@@ -26,6 +26,8 @@ main() {
         'test|lib/library.dart': readTestFile('library.dart'),
         'test|web/entry_point.dart': readTestFile('entry_point.dart.test'),
         'js|lib/js.dart': readJsPackageFile('js.dart'),
+        'js|lib/src/mirrors.dart': readJsPackageFile('src/mirrors.dart'),
+        'js|lib/src/static.dart': readJsPackageFile('src/static.dart'),
         'js|lib/src/js_impl.dart': readJsPackageFile('src/js_impl.dart'),
         'js|lib/src/metadata.dart': readJsPackageFile('src/metadata.dart'),
       }, null);

test/transformer/js_proxy_generator_test.dart

@@ -6,13 +6,14 @@ library js.test.transformer.proxy_generator_test;
 
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
+import 'package:barback/barback.dart';
 import 'package:js/src/transformer/js_proxy_generator.dart';
+import 'package:js/src/transformer/utils.dart';
 import 'package:source_maps/refactor.dart';
 import 'package:source_span/source_span.dart';
 import 'package:unittest/unittest.dart';
 
 import 'utils.dart';
-import 'package:barback/barback.dart';
 
 main() {
 
@@ -38,9 +39,7 @@ main() {
           testLib.getType('ContextImpl'),
           testLib.getType('JsFooImpl'),
           testLib.getType('JsBarImpl')]);
-      var jsMetadataLib = jsLib
-          .exportedLibraries
-          .singleWhere((l) => l.name == 'js.metadata');
+      var jsMetadataLib = getMetadataLib(jsLib);
       var testSourceFile = new SourceFile(testLibSource);
       var transaction = new TextEditTransaction(testLibSource, testSourceFile);
       var id = new AssetId('test', 'lib/test.dart');

test/transformer/library_transformer_test.dart

@@ -20,6 +20,8 @@ main() {
       var testHelper = new TestHelper([[transformer]], {
         'test|lib/library.dart': readTestFile('library.dart'),
         'js|lib/js.dart': readJsPackageFile('js.dart'),
+        'js|lib/src/mirrors.dart': readJsPackageFile('src/mirrors.dart'),
+        'js|lib/src/static.dart': readJsPackageFile('src/static.dart'),
         'js|lib/src/js_impl.dart': readJsPackageFile('src/js_impl.dart'),
         'js|lib/src/metadata.dart': readJsPackageFile('src/metadata.dart'),
       }, null);

test/transformer/remove_mirrors_transformer_test.dart

@@ -0,0 +1,49 @@
+// 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 js.remove_mirrors_transformer_test;
+
+import 'dart:async';
+
+import 'package:barback/barback.dart';
+import 'package:js/src/transformer/remove_mirrors_transformer.dart';
+import 'package:unittest/unittest.dart';
+
+import 'utils.dart';
+
+main() {
+
+  group("$RemoveMirrorsTransformer", () {
+    test('should replace the mirrors.dart import', () {
+      var transformer = new RemoveMirrorsTransformer();
+      var barback = new Barback(new TestPackageProvider());
+      barback.updateTransformers('js', [[transformer]]);
+      var id = new AssetId('js', 'lib/js.dart');
+      barback.updateSources([id]);
+      return barback.getAssetById(id)
+          .then((asset) => asset.readAsString())
+          .then((source) {
+            expect(source,
+                contains("export 'package:js/src/static.dart';"));
+            expect(source,
+                isNot(contains(
+                    "export 'package:js/src/mirrors.dart';")));
+          });
+    });
+  });
+
+}
+
+class TestPackageProvider implements PackageProvider {
+  Iterable<String> get packages => ['js'];
+
+  Future<Asset> getAsset(AssetId id) {
+    if (id.package == 'js' && id.path == 'lib/js.dart') {
+      return new Future.value(
+          new Asset.fromString(id, readJsPackageFile('js.dart')));
+    }
+    return null;
+  }
+
+}

test/transformer/scanning_visitor_test.dart

@@ -6,6 +6,7 @@ library js.test.transformer.scanning_visitor_test;
 
 import 'package:analyzer/src/generated/element.dart';
 import 'package:js/src/transformer/scanning_visitor.dart';
+import 'package:js/src/transformer/utils.dart';
 import 'package:js/src/js_elements.dart';
 import 'package:unittest/unittest.dart';
 
@@ -22,10 +23,7 @@ main() {
       var analyserInfo = initAnalyzer();
       testLib = analyserInfo.testLib;
       jsLib = analyserInfo.jsLib;
-      jsMetadataLib = jsLib
-          .exportedLibraries
-          .singleWhere((l) => l.name == 'js.metadata');
-
+      jsMetadataLib = getMetadataLib(jsLib);
     });
 
     test('should find JsProxy annotated classes', () {

test/transformer/test_sources/library.dart

@@ -4,7 +4,6 @@
 
 library test.library;
 
-import 'dart:js' show JsObject;
 import 'package:js/js.dart';
 
 abstract class Context extends JsInterface {