Add built-in timeouts to scheduled_test.

pkg/scheduled_test/lib/src/schedule_error.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 schedule_error;
 
 import 'dart:async';
 
 import 'schedule.dart';
 import 'task.dart';
 import 'utils.dart';
 
 /// A wrapper for errors that occur during a scheduled test.
 class ScheduleError extends AsyncError {
   /// The schedule during which this error occurred.
   final Schedule schedule;
 
   /// The task that was running when this error occurred. This may be `null` if
   /// there was no such task.
   final Task task;
 
-  /// Whether the schedule was finished executing at the time the error was
-  /// detected.
-  final bool _scheduleWasDone;
+  /// The state of the schedule at the time the error was detected.
+  final ScheduleState _stateWhenDetected;
 
   /// Creates a new [ScheduleError] wrapping [error]. The metadata in
   /// [AsyncError]s and [ScheduleError]s will be preserved.
   factory ScheduleError.from(Schedule schedule, error, {stackTrace,
       AsyncError cause, Task task}) {
     if (error is ScheduleError) {
       if (schedule == null) schedule = error.schedule;
       if (task == null) task = error.task;
     }
 
     if (error is AsyncError) {
       // Overwrite the explicit stack trace, because it probably came from a
       // rethrow in the first place.
       stackTrace = error.stackTrace;
       if (cause == null) cause = error.cause;
       error = error.error;
     }
 
     return new ScheduleError(schedule, error, stackTrace, cause, task);
   }
 
   ScheduleError(Schedule schedule, error, stackTrace, AsyncError cause,
       this.task)
       : super.withCause(error, stackTrace, cause),
         this.schedule = schedule,
-        this._scheduleWasDone = schedule.done;
+        this._stateWhenDetected = schedule.state;
 
   String toString() {
     var result = new StringBuffer();
 
     var errorString = error.toString();
     if (errorString.contains("\n")) {
       result.add('ScheduleError:\n');
       result.add(prefixLines(errorString.trim()));
       result.add("\n\n");
     } else {
       result.add('ScheduleError: "$errorString"\n');
     }
 
     result.add('Stack trace:\n');
     result.add(prefixLines(stackTrace.toString().trim()));
     result.add("\n\n");
 
     if (task != null) {
       result.add('Error detected during task in queue "${task.queue}":\n');
       result.add(task.generateTree());
-    } else if (_scheduleWasDone) {
+    } else if (_stateWhenDetected == ScheduleState.DONE) {
       result.add('Error detected after all tasks in the queue had finished.');
-    } else {
+    } else { // _stateWhenDetected == ScheduleState.SET_UP
       result.add('Error detected before the schedule started running.');
     }
 
     return result.toString();
   }
 }