Port of github.com/polymer/polymer.

pkg/polymer/test/attr_mustache_test.dart

+// 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:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+import 'package:polymer/polymer.dart';
+
+@CustomTag('x-target')
+class XTarget extends PolymerElement {
+  final Completer _found = new Completer();
+  Future get foundSrc => _found.future;
+
+  // force an mdv binding
+  bind(name, model, path) =>
+      TemplateElement.mdvPackage(this).bind(name, model, path);
+
+  inserted() {
+    testSrcForMustache();
+  }
+
+  attributeChanged(name, oldValue) {
+    testSrcForMustache();
+    if (attributes[name] == '../testSource') {
+      _found.complete();
+    }
+  }
+
+  testSrcForMustache() {
+    expect(attributes['src'], isNot(matches(Polymer.bindPattern)),
+        reason: 'attribute does not contain {{...}}');
+  }
+}
+
+@CustomTag('x-test')
+class XTest extends PolymerElement {
+  @observable var src = 'testSource';
+}
+
+main() {
+  useHtmlConfiguration();
+
+  test('mustache attributes', () {
+    final xtest = document.query('#test').xtag;
+    final xtarget = xtest.shadowRoot.query('#target').xtag;
+    return xtarget.foundSrc;
+  });
+}