Port of github.com/polymer/polymer.

pkg/polymer/test/attr_deserialize_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:html';
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+import 'package:polymer/polymer.dart';
+
+@CustomTag('my-element')
+class MyElement extends PolymerElement {
+  @published double volume;
+  @published int factor;
+  @published bool crankIt;
+  @published String msg;
+  @published DateTime time;
+  @published Object json;
+}
+
+main() {
+  useHtmlConfiguration();
+
+  test('attributes were deserialized', () {
+    MyElement elem = query('my-element').xtag;
+    final msg = 'property should match attribute.';
+    expect(elem.volume, 11.0, reason: '"volume" should match attribute');
+    expect(elem.factor, 3, reason: '"factor" should match attribute');
+    expect(elem.crankIt, true, reason: '"crankIt" should match attribute');
+    expect(elem.msg, "Yo!", reason: '"msg" should match attribute');
+    expect(elem.time, DateTime.parse('2013-08-08T18:34Z'),
+        reason: '"time" should match attribute');
+    expect(elem.json, {'here': 'is', 'some': 'json', 'x': 123},
+        reason: '"json" should match attribute');
+
+    var text = elem.shadowRoot.text;
+    // Collapse adjacent whitespace like a browser would:
+    text = text.replaceAll('\n', ' ').replaceAll(new RegExp(r'\s+'), ' ');
+
+    // Note: using "${33.0}" because the toString differs in JS vs Dart VM.
+    expect(text, " Yo! The volume is ${33.0} !! The time is "
+        "2013-08-08 18:34:00.000Z and here's some JSON: "
+        "{here: is, some: json, x: 123} ",
+        reason: 'text should match expected HTML template');
+  });
+}