add enumerate to the default filter set

pkg/polymer_expressions/test/globals_test.dart

Index: pkg/polymer_expressions/test/globals_test.dart
diff --git a/pkg/polymer_expressions/test/globals_test.dart b/pkg/polymer_expressions/test/globals_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..82d7e62d880a2f3bf8ab967fd793fdb9adf8a396
--- /dev/null
+++ b/pkg/polymer_expressions/test/globals_test.dart
@@ -0,0 +1,54 @@
+// Copyright (c) 2013, 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.
+
+import 'dart:async';
+import 'dart:html';
+
+import 'package:mdv/mdv.dart' as mdv;
+import 'package:observe/observe.dart';
+import 'package:observe/src/microtask.dart';
+import 'package:polymer_expressions/polymer_expressions.dart';
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_enhanced_config.dart';
+
+main() {
+  mdv.initialize();
+  useHtmlEnhancedConfiguration();
+
+  var testDiv;
+  group('enumerate', () {
+    setUp(() {
+      testDiv = new Element.html('''
+          <div id="test">
+            <template bind>
+              <template repeat="{{entry in this | enumerate}}">
+                <div>Item {{ entry.index }} is {{ entry.value }}</div>
+              </template>
+            </template>
+          </div>''');
+      document.body.nodes.add(testDiv);
+    });
+
+    tearDown(() {
+      testDiv..unbindAll()..remove();
+      testDiv = null;
+    });
+
+    test('should enumerate item and index', wrapMicrotask(() {
+      testDiv.query('template')
+          ..bindingDelegate = new PolymerExpressions()
+          ..model = toObservable(
+              ['hello', 'from', 'polymer', 'expressions']);
+
+      performMicrotaskCheckpoint();
+
+      expect(testDiv.queryAll('div').map((n) => n.text), [
+        'Item 0 is hello',
+        'Item 1 is from',
+        'Item 2 is polymer',
+        'Item 3 is expressions',
+      ]);
+    }));
+  });
+}