port polymer data binding tests

pkg/polymer/test/template_distribute_dynamic_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:polymer/polymer.dart';
+import 'package:polymer/platform.dart' as Platform;
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+
+@CustomTag('x-test')
+class XTest extends PolymerElement {
+  @observable List list;
+
+  final _inserted = new Completer();
+  Future onTestDone;
+
+  created() {
+    super.created();
+    onTestDone = _inserted.future.then(_runTest);
+  }
+
+  inserted() => _inserted.complete();
+
+  _runTest(_) {
+    list = [
+      {'name': 'foo'},
+      {'name': 'bar'}
+    ];
+
+    Platform.flush();
+    Platform.endOfMicrotask(expectAsync0(() {
+      // tickle SD polyfill
+      offsetHeight;
+      var children = this.$['echo'].children;
+      expect(children[0].localName, 'template', reason:
+          'shadowDOM dynamic distribution via template');
+      expect(children[1].text, 'foo', reason:
+          'shadowDOM dynamic distribution via template');
+      expect(children[2].text, 'bar', reason:
+          'shadowDOM dynamic distribution via template');
+
+      // TODO(jmesserly): restore this if we get the JS interop capability.
+      /*
+      if (window.ShadowDOMPolyfill) {
+        var actualChildren = this.$.echo.impl.children;
+        chai.assert.equal(actualChildren.length, 4,
+          'shadowDOMPolyfill distributes expected number of actual children.');
+      }
+      */
+    }));
+  }
+}
+
+main() {
+  useHtmlConfiguration();
+
+  test('inserted called', () => query('x-test').xtag.onTestDone);
+}