test.py In case we don't have any TestCases, don't block

tools/testing/dart/test_runner.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Classes and methods for executing tests.
  *
  * This module includes:
  * - Managing parallel execution of tests, including timeout checks.
  * - Evaluating the output of each test as pass/fail/crash/timeout.
@@ skipping 1909 matching lines @@
  * closed.
  */
 class TestCaseCompleter {
   static final COMPLETED_STATES = [dgraph.NodeState.Failed,
                                    dgraph.NodeState.Successful];
   final dgraph.Graph graph;
   final TestCaseEnqueuer enqueuer;
   final CommandQueue commandQueue;
 
   Map<Command, CommandOutput> _outputs = new Map<Command, CommandOutput>();
+  bool _closed = false;
   StreamController<TestCase> _controller = new StreamController<TestCase>();
 
   TestCaseCompleter(this.graph, this.enqueuer, this.commandQueue) {
     var eventCondition = graph.events.where;
 
     // Store all the command outputs -- they will be delivered synchronously
     // (i.e. before state changes in the graph)
     commandQueue.completedCommands.listen((CommandOutput output) {
       _outputs[output.command] = output;
     });
 
     // Listen for NodeState.Processing -> NodeState.{Successfull,Failed}
     // changes.
     eventCondition((event) => event is dgraph.StateChangedEvent)
         .listen((dgraph.StateChangedEvent event) {
           if (event.from == dgraph.NodeState.Processing) {
             assert(COMPLETED_STATES.contains(event.to));
             _completeTestCasesIfPossible(event.node.userData);
 
-            if (graph.isSealed && enqueuer.remainingTestCases.isEmpty) {
+            if (!_closed &&
+                graph.isSealed &&
+                enqueuer.remainingTestCases.isEmpty) {
               _controller.close();
+              _closed = true;
             }
           }
     });
+
+    // Listen also for GraphSealedEvent's. If there is not a single node in the
+    // graph, we still want to finish after the graph was sealed.
+    eventCondition((event) => event is dgraph.GraphSealedEvent)
+        .listen((dgraph.GraphSealedEvent event) {
+          if (!_closed && enqueuer.remainingTestCases.isEmpty) {
+            _controller.close();
+            _closed = true;
+          }
+    });
   }
 
   Stream<TestCase> get finishedTestCases => _controller.stream;
 
   void _completeTestCasesIfPossible(Command command) {
     assert(_outputs[command] != null);
 
     var testCases = enqueuer.command2testCases[command];
 
     // Update TestCases with command outputs
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     }
   }
 
   void eventAllTestsDone() {
     for (var listener in _eventListener) {
       listener.allDone();
     }
     _allDone();
   }
 }