Sample test for custom elements.

tests/html/custom_elements_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.
+
+library blob_test;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html';
+
+class CustomType extends Element {
+  bool onCreatedCalled = false;
+  void onCreated() {
+    onCreatedCalled = true;
+  }
+}
+
+class NotAnElement {}
+
+main() {
+  useHtmlConfiguration();
+
+  test('register', () {
+    document.register('x-type1', CustomType);
+
+    var element = new Element.tag('x-type1');
+    expect(element, isNotNull);
+    expect(element is CustomType, isTrue);
+    expect(element.onCreatedCalled, isTrue);
+  });
+
+  test('register twice', () {
+    document.register('x-type2', CustomType);
+    expect(() {
+      document.register('x-type2', CustomType);
+    }, throws, reason: 'Cannot register a tag more than once.');
+
+    document.register('x-type3', CustomType);
+
+    var element = new Element.tag('x-type3');
+    expect(element, isNotNull);
+    expect(element is CustomType, isTrue);
+  });
+
+  test('register null', () {
+    expect(() {
+      document.register('x-type4', null);
+    }, throws, reason: 'Cannot register a null type.');
+  });
+
+  test('register native', () {
+    expect(() {
+      document.register('x-type5', BodyElement);
+    }, throws, reason: 'Cannot register a native element.');
+  });
+
+  test('register non-element', () {
+    expect(() {
+      document.register('x-type6', NotAnElement);
+    }, throws, reason: 'Cannot register a non-element.');
+  });
+
+  test('pre-registration construction', () {
+    var dom = new Element.html('<div><x-type7></x-type7></div>');
+    var preElement = dom.children[0];
+    expect(preElement, isNotNull);
+    expect(preElement is UnknownElement, isTrue);
+
+    document.register('x-type7', CustomType);
+
+    var postElement = dom.children[0];

[Anton Muhin, 2013/02/11 14:04:30]

weird semantics.  I wonder what happens in case of various queries which return
NodeLists---those lists are cached sometimes.

And it might be a good idea to add some tests for event listeners---I'd suspect
that registration should do something to them if one can install a listener on
unknown element in the first place.

+    expect(postElement, isNotNull);
+    expect(postElement is CustomType, isTrue);
+    expect(postElement.onCreatedCalled, isTrue);
+
+    // Element from first query remains an UnknownElement.
+    expect(preElement is UnknownElement, isTrue);
+    expect(preElement.parent, isNull);
+    expect(dom.children.length, 1);
+  });
+}