Support proxying of objects between JS and Dart.

tests/html/js_interop_obj_passing_test.dart

+// Copyright (c) 2012, 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('JsInteropObjPassingTest');
+#import('../../pkg/unittest/unittest.dart');
+#import('../../pkg/unittest/html_config.dart');
+#import('dart:html');
+#import('dart:isolate');
+
+injectSource(code) {
+  final script = new ScriptElement();
+  script.type = 'text/javascript';
+  script.innerHTML = code;
+  document.body.nodes.add(script);
+}
+
+var jsProxyTest = """
+  function TestType(x) {
+    this.x = x;
+  }
+  TestType.prototype.razzle = function () {
+    return this.x * 2;
+  }
+  var data = new TestType(21);
+
+  var port1 = new ReceivePortSync();
+  port1.receive(function (x) {
+    return x.razzle();
+  });
+  window.registerPort('test1a', port1.toSendPort());
+
+  var port2 = window.lookupPort('test1b');
+  port2.callSync(data);
+""";
+
+var dartProxyTest = """
+  var port2 = new ReceivePortSync();
+  port2.receive(function (x) {
+    var port1 = window.lookupPort('test2a');
+    port1.callSync(x);
+  });
+  window.registerPort('test2b', port2.toSendPort());
+""";
+
+main() {
+  useHtmlConfiguration();
+
+  test('js-proxy', () {
+    int invoked = 0;
+
+    var port2 = new ReceivePortSync();
+    port2.receive((x) {
+      var port1 = window.lookupPort('test1a');
+      var result = port1.callSync(x);
+      expect(result, equals(42));
+      ++invoked;
+    });
+    window.registerPort('test1b', port2.toSendPort());
+
+    injectSource(jsProxyTest);
+    expect(invoked, equals(1));
+  });
+
+  test('dart-proxy', () {
+    injectSource(dartProxyTest);
+
+    var buffer = new StringBuffer();
+    buffer.add('hello');
+
+    var port1 = new ReceivePortSync();
+    port1.receive((x) => x.add(' from dart'));
+    window.registerPort('test2a', port1.toSendPort());
+
+    var port2 = window.lookupPort('test2b');
+    port2.callSync(buffer);
+
+    expect(buffer.toString(), equals('hello from dart'));
+  });
+}