Add some more tests for Element and Node.

client/tests/client/html/ElementTests.dart

Index: client/tests/client/html/ElementTests.dart
diff --git a/client/tests/client/html/ElementTests.dart b/client/tests/client/html/ElementTests.dart
index b840480fcb75e0d7ed047effd79895ba102c57e4..0bf2869a113372af5611b0e85009ee0eb3b1d0e2 100644
--- a/client/tests/client/html/ElementTests.dart
+++ b/client/tests/client/html/ElementTests.dart
@@ -79,6 +79,11 @@ void testElement() {
   });
 
   group('constructors', () {
+    test('error', () {
+      Expect.throws(() => new Element.html('<br/><br/>'),
+          (e) => e is IllegalArgumentException);
+    });
+
     test('a', () => testConstructorHelper('a', '<a>foo</a>', 'foo',
         (element) => element is AnchorElement));
     test('area', () => testConstructorHelper('area', '<area>foo</area>', '',
@@ -685,4 +690,149 @@ void testElement() {
       Expect.isTrue(range[1] is InputElement);
     });
   });
+
+  group('classes', () {
+    Element makeElementWithClasses() =>
+      new Element.html('<div class="foo bar baz"></div>');
+
+    Set<String> makeClassSet() => makeElementWithClasses().classes;
+
+    Set<String> extractClasses(Element el) {
+      final match = new RegExp('class="([^"]+)"').firstMatch(el.outerHTML);
+      return new Set.from(match[1].split(' '));
+    }
+
+    test('affects the "class" attribute', () {
+      final el = makeElementWithClasses();
+      el.classes.add('qux');
+      Expect.setEquals(['foo', 'bar', 'baz', 'qux'], extractClasses(el));
+    });
+
+    test('is affected by the "class" attribute', () {
+      final el = makeElementWithClasses();
+      el.attributes['class'] = 'foo qux';
+      Expect.setEquals(['foo', 'qux'], el.classes);
+    });
+
+    test('classes=', () {
+      final el = makeElementWithClasses();
+      el.classes = ['foo', 'qux'];
+      Expect.setEquals(['foo', 'qux'], el.classes);
+      Expect.setEquals(['foo', 'qux'], extractClasses(el));
+    });
+
+    test('toString', () {
+      Expect.setEquals(['foo', 'bar', 'baz'],
+          makeClassSet().toString().split(' '));
+      Expect.equals('', makeElement().classes.toString());
+    });
+
+    test('forEach', () {
+      final classes = <String>[];
+      makeClassSet().forEach(classes.add);
+      Expect.setEquals(['foo', 'bar', 'baz'], classes);
+    });
+
+    test('iterator', () {
+      final classes = <String>[];
+      for (var el in makeClassSet()) {
+        classes.add(el);
+      }
+      Expect.setEquals(['foo', 'bar', 'baz'], classes);
+    });
+
+    test('map', () {
+      Expect.setEquals(['FOO', 'BAR', 'BAZ'],
+          makeClassSet().map((c) => c.toUpperCase()));
+    });
+
+    test('filter', () {
+      Expect.setEquals(['bar', 'baz'],
+          makeClassSet().filter((c) => c.contains('a')));
+    });
+
+    test('every', () {
+      Expect.isTrue(makeClassSet().every((c) => c is String));
+      Expect.isFalse(
+          makeClassSet().every((c) => c.contains('a')));
+    });
+
+    test('some', () {
+      Expect.isTrue(
+          makeClassSet().some((c) => c.contains('a')));
+      Expect.isFalse(makeClassSet().some((c) => c is num));
+    });
+
+    test('isEmpty', () {
+      Expect.isFalse(makeClassSet().isEmpty());
+      Expect.isTrue(makeElement().classes.isEmpty());
+    });
+
+    test('length', () {
+      Expect.equals(3, makeClassSet().length);
+      Expect.equals(0, makeElement().classes.length);
+    });
+
+    test('contains', () {
+      Expect.isTrue(makeClassSet().contains('foo'));
+      Expect.isFalse(makeClassSet().contains('qux'));
+    });
+
+    test('add', () {
+      final classes = makeClassSet();
+      classes.add('qux');
+      Expect.setEquals(['foo', 'bar', 'baz', 'qux'], classes);
+
+      classes.add('qux');
+      final list = new List.from(classes);
+      list.sort((a, b) => a.compareTo(b));
+      Expect.listEquals(['bar', 'baz', 'foo', 'qux'], list,
+          "The class set shouldn't have duplicate elements.");
+    });
+
+    test('remove', () {
+      final classes = makeClassSet();
+      classes.remove('bar');
+      Expect.setEquals(['foo', 'baz'], classes);
+      classes.remove('qux');
+      Expect.setEquals(['foo', 'baz'], classes);
+    });
+
+    test('addAll', () {
+      final classes = makeClassSet();
+      classes.addAll(['bar', 'qux', 'bip']);
+      Expect.setEquals(['foo', 'bar', 'baz', 'qux', 'bip'], classes);
+    });
+
+    test('removeAll', () {
+      final classes = makeClassSet();
+      classes.removeAll(['bar', 'baz', 'qux']);
+      Expect.setEquals(['foo'], classes);
+    });
+
+    test('isSubsetOf', () {
+      final classes = makeClassSet();
+      Expect.isTrue(classes.isSubsetOf(['foo', 'bar', 'baz']));
+      Expect.isTrue(classes.isSubsetOf(['foo', 'bar', 'baz', 'qux']));
+      Expect.isFalse(classes.isSubsetOf(['foo', 'bar', 'qux']));
+    });
+
+    test('containsAll', () {
+      final classes = makeClassSet();
+      Expect.isTrue(classes.containsAll(['foo', 'baz']));
+      Expect.isFalse(classes.containsAll(['foo', 'qux']));
+    });
+
+    test('intersection', () {
+      final classes = makeClassSet();
+      Expect.setEquals(['foo', 'baz'],
+          classes.intersection(['foo', 'qux', 'baz']));
+    });
+
+    test('clear', () {
+      final classes = makeClassSet();
+      classes.clear();
+      Expect.setEquals([], classes);
+    });
+  });
 }