Centralized event streams

runtime/observatory/tests/observatory_ui/nav/notify_exception/exception_test.dart

Index: runtime/observatory/tests/observatory_ui/nav/notify_exception/exception_test.dart
diff --git a/runtime/observatory/tests/observatory_ui/nav/notify_exception/exception_test.dart b/runtime/observatory/tests/observatory_ui/nav/notify_exception/exception_test.dart
index be9fdc5fdacf638dd5e875ab40ec6c4ef9bfa7a8..4696ee8c8fe81f0b9e5a4de71ee37424886c0221 100644
--- a/runtime/observatory/tests/observatory_ui/nav/notify_exception/exception_test.dart
+++ b/runtime/observatory/tests/observatory_ui/nav/notify_exception/exception_test.dart
@@ -9,46 +9,42 @@ import 'package:observatory/src/elements/nav/notify_exception.dart';
 main() {
   NavNotifyExceptionElement.tag.ensureRegistration();
 
-  final StackTrace stacktrace = new StackTrace.fromString('stacktrace string');
+  final st = new StackTrace.fromString('stacktrace string');
   group('normal exception', () {
-    final Exception exception = new Exception('exception message');
+    final ex = new Exception('exception message');
     group('instantiation', () {
       test('no stacktrace', () {
-        final NavNotifyExceptionElement e =
-                                      new NavNotifyExceptionElement(exception);
+        final e = new NavNotifyExceptionElement(ex);
         expect(e, isNotNull, reason: 'element correctly created');
-        expect(e.exception, equals(exception));
+        expect(e.exception, equals(ex));
         expect(e.stacktrace, isNull);
       });
       test('with stacktrace', () {
-        final NavNotifyExceptionElement e =
-              new NavNotifyExceptionElement(exception, stacktrace: stacktrace);
+        final e = new NavNotifyExceptionElement(ex, stacktrace: st);
         expect(e, isNotNull, reason: 'element correctly created');
-        expect(e.exception, equals(exception));
-        expect(e.stacktrace, equals(stacktrace));
+        expect(e.exception, equals(ex));
+        expect(e.stacktrace, equals(st));
       });
     });
     group('elements', () {
       test('created after attachment (no stacktrace)', () async {
-        final NavNotifyExceptionElement e =
-                                      new NavNotifyExceptionElement(exception);
+        final e = new NavNotifyExceptionElement(ex);
         document.body.append(e);
         await e.onRendered.first;
         expect(e.children.length, isNonZero, reason: 'has elements');
-        expect(e.innerHtml.contains(exception.toString()), isTrue);
-        expect(e.innerHtml.contains(stacktrace.toString()), isFalse);
+        expect(e.innerHtml.contains(ex.toString()), isTrue);
+        expect(e.innerHtml.contains(st.toString()), isFalse);
         e.remove();
         await e.onRendered.first;
         expect(e.children.length, isZero, reason: 'is empty');
       });
       test('created after attachment (with stacktrace)', () async {
-        final NavNotifyExceptionElement e =
-              new NavNotifyExceptionElement(exception, stacktrace: stacktrace);
+        final e = new NavNotifyExceptionElement(ex, stacktrace: st);
         document.body.append(e);
         await e.onRendered.first;
         expect(e.children.length, isNonZero, reason: 'has elements');
-        expect(e.innerHtml.contains(exception.toString()), isTrue);
-        expect(e.innerHtml.contains(stacktrace.toString()), isTrue);
+        expect(e.innerHtml.contains(ex.toString()), isTrue);
+        expect(e.innerHtml.contains(st.toString()), isTrue);
         e.remove();
         await e.onRendered.first;
         expect(e.children.length, isZero, reason: 'is empty');
@@ -58,7 +54,7 @@ main() {
       NavNotifyExceptionElement e;
       StreamSubscription sub;
       setUp(() async {
-        e = new NavNotifyExceptionElement(exception, stacktrace: stacktrace);
+        e = new NavNotifyExceptionElement(ex, stacktrace: st);
         document.body.append(e);
         await e.onRendered.first;
       });
@@ -74,9 +70,8 @@ main() {
       test('onDelete events (DOM)', () async {
         sub = e.onDelete.listen(expectAsync((ExceptionDeleteEvent event) {
           expect(event, isNotNull, reason: 'event is passed');
-          expect(event.exception, equals(exception),
-                                              reason: 'exception is the same');
-          expect(event.stacktrace, equals(stacktrace),
+          expect(event.exception, equals(ex), reason: 'exception is the same');
+          expect(event.stacktrace, equals(st),
                                             reason: 'stacktrace is the same');
         }, count: 1, reason: 'event is fired'));
         e.querySelector('button').click();
@@ -84,9 +79,8 @@ main() {
       test('onDelete events (code)', () async {
         sub = e.onDelete.listen(expectAsync((ExceptionDeleteEvent event) {
           expect(event, isNotNull, reason: 'event is passed');
-          expect(event.exception, equals(exception),
-                                              reason: 'exception is the same');
-          expect(event.stacktrace, equals(stacktrace),
+          expect(event.exception, equals(ex), reason: 'exception is the same');
+          expect(event.stacktrace, equals(st),
                                             reason: 'stacktrace is the same');
         }, count: 1, reason: 'event is fired'));
         e.delete();