Don't early-exit teardowns after a signal.

lib/src/backend/group.dart

 // Copyright (c) 2015, 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 test.backend.group;
 
 import 'dart:async';
 
 import '../utils.dart';
 import 'invoker.dart';
@@ skipping 56 matching lines @@
     }
 
     return Future.forEach(setUps, (setUp) => setUp());
   }
 
   /// Run the tear-up functions for this and any parent groups.
   ///
   /// If no set-up functions are declared, this returns a [Future] that
   /// completes immediately.
   Future runTearDowns() {
-    // TODO(nweiz): Use async/await here once issue 23497 has been fixed in two
-    // stable versions.
-    if (parent == null) {
-      return Future.forEach(tearDowns.reversed, _errorsDontStopTest);
-    }
+    return Invoker.current.unclosable(() {
+      var tearDowns = [];
+      for (var group = this; group != null; group = group.parent) {
+        tearDowns.addAll(group.tearDowns.reversed);
+      }
 
-    return Future.forEach(tearDowns.reversed, _errorsDontStopTest)
-        .then((_) => parent.runTearDowns());
+      return Future.forEach(tearDowns, _errorsDontStopTest);
+    });
   }
 
   /// Runs [body] with special error-handling behavior.
   ///
   /// Errors emitted [body] will still cause be the test to fail, but they won't
   /// cause it to *stop*. In particular, they won't remove any outstanding
   /// callbacks registered outside of [body].
   Future _errorsDontStopTest(body()) {
     var completer = new Completer();
 
     Invoker.current.addOutstandingCallback();
     Invoker.current.waitForOutstandingCallbacks(() {
       new Future.sync(body).whenComplete(completer.complete);
     }).then((_) => Invoker.current.removeOutstandingCallback());
 
     return completer.future;
   }
 }