Provide noSuchMethod hook for UnknownElement

tests/html/unknownelement_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('UnknownElementTest');
+#import('../../lib/unittest/unittest.dart');
+#import('../../lib/unittest/html_config.dart');
+#import('dart:html');
+
+main() {
+  useHtmlConfiguration();
+
+  var foo = new Element.tag('foo');
+  foo.id = 'foo';
+  var bar = new Element.tag('bar');
+  bar.id = 'bar';
+  document.body.nodes.addAll([foo, bar]);
+
+  test('type-check', () {
+      expect(foo is UnknownElement, isTrue);
+      expect(bar is UnknownElement, isTrue);
+      expect(query('#foo'), equals(foo));
+      expect(query('#bar'), equals(bar));
+    });
+
+  test('dispatch-fail', () {
+      expect(() => foo.method1(), throwsException);
+      expect(() => foo.field1, throwsException);
+      expect(() { foo.field1 = 42; }, throwsException);
+    });
+
+  test('dispatch', () {
+      dispatch(element, name, args) {
+        if (element.xtag == null) {
+          element.xtag = new Map();
+        }
+        var map = element.xtag;
+
+        // FIXME: Remove once VM and Dart2JS converge.
+        name = name.replaceFirst(' ', ':');
+        switch (element.tagName.toLowerCase()) {
+          case 'foo':
+            switch (name) {
+              case 'get:x':
+                return 42;
+              case 'baz':
+                return '${element.id} - ${args[0]}';
+            }
+            break;
+          case 'bar':
+            switch (name) {
+              case 'get:y':
+                return map['y'];
+              case 'set:y':
+                map['y'] = args[0];
+                return;
+            }
+            break;
+        }
+        throw new NoSuchMethodException(element, name, args);
+      }
+      dynamicUnknownElementDispatcher = dispatch;
+
+      expect(foo.x, equals(42));
+      expect(() { foo.x = 7; }, throwsException);
+      expect(foo.id, equals('foo'));
+      expect(() => bar.x, throwsException);
+      bar.y = 11;
+      expect(bar.y, equals(11));
+      expect(foo.baz('hello'), equals('foo - hello'));
+    });
+}