public void canceled_transition_reverts_back_to_original_state()
{
var factory = new StateMachineTaskFactory <State>();
var cancellationTokenSource = new CancellationTokenSource();
factory.RegisterTransition(State.Starting, State.Started, (ct, o) => TaskUtil.FromResult(true));
factory.RegisterTransition(State.Stopping, State.Stopped, (ct, o) => TaskUtil.Delay(TimeSpan.FromSeconds(3), cancellationTokenSource.Token));
factory.StateChanged += (s, e) =>
{
if (e.NewState == State.Stopping)
{
// cancel the stop
cancellationTokenSource.Cancel();
}
};
var startedTask = factory.TransitionTo(State.Started);
var stoppedTask = factory.TransitionTo(State.Stopped, cancellationTokenSource.Token);
startedTask.Wait(TimeSpan.FromSeconds(3));
try
{
stoppedTask.Wait(TimeSpan.FromSeconds(3));
Assert.True(false, "Failed to throw exception.");
}
catch (AggregateException ex)
{
Assert.Equal(1, ex.InnerExceptions.Count);
Assert.IsType <OperationCanceledException>(ex.InnerExceptions[0]);
Assert.Equal(State.Started, factory.State);
}
}
public void transition_to_returns_same_task_if_called_multiple_times_whilst_initial_task_is_still_in_progress()
{
var factory = new StateMachineTaskFactory <State>();
factory.RegisterTransition(State.Starting, State.Started, (ct, o) => TaskUtil.Delay(TimeSpan.FromMilliseconds(250)));
var initialTask = factory.TransitionTo(State.Started);
Assert.Equal(initialTask, factory.TransitionTo(State.Started));
Assert.Equal(initialTask, factory.TransitionTo(State.Started));
Assert.Equal(initialTask, factory.TransitionTo(State.Started));
Assert.True(initialTask.Wait(TimeSpan.FromSeconds(3)));
}
public void transition_to_ensures_previous_transition_is_first_completed_before_starting_subsequent_transition()
{
var factory = new StateMachineTaskFactory <State>();
factory.RegisterTransition(State.Starting, State.Started, (ct, o) => TaskUtil.Delay(TimeSpan.FromMilliseconds(10)));
factory.RegisterTransition(State.Stopping, State.Stopped, (ct, o) => TaskUtil.Delay(TimeSpan.FromMilliseconds(10)));
var startedAt = DateTime.MinValue;
var stoppedAt = DateTime.MinValue;
var startedTask = factory.TransitionTo(State.Started).ContinueWith(x => startedAt = DateTime.UtcNow, TaskContinuationOptions.ExecuteSynchronously);
var stoppedTask = factory.TransitionTo(State.Stopped).ContinueWith(x => stoppedAt = DateTime.UtcNow, TaskContinuationOptions.ExecuteSynchronously);
Assert.True(Task.WaitAll(new Task[] { startedTask, stoppedTask }, TimeSpan.FromSeconds(3)), "Timed out waiting for tasks to complete.");
Assert.True(stoppedAt > startedAt, "stoppedAt is " + stoppedAt.Millisecond + " and startedAt is " + startedAt.Millisecond + ", difference is " + (stoppedAt - startedAt).ToString());
}
public void state_gets_the_current_state()
{
var factory = new StateMachineTaskFactory <State>(State.Stopped);
factory.RegisterTransition(State.Starting, State.Started, (ct, o) => TaskUtil.Delay(TimeSpan.FromMilliseconds(100)));
factory.RegisterTransition(State.Stopping, State.Stopped, (ct, o) => TaskUtil.Delay(TimeSpan.FromMilliseconds(100)));
var task = factory.TransitionTo(State.Started);
Assert.Equal(State.Starting, factory.State);
task.Wait(TimeSpan.FromSeconds(3));
Assert.Equal(State.Started, factory.State);
task = factory.TransitionTo(State.Stopped);
Assert.Equal(State.Stopping, factory.State);
task.Wait(TimeSpan.FromSeconds(3));
Assert.Equal(State.Stopped, factory.State);
}
public void transition_to_can_be_canceled()
{
var factory = new StateMachineTaskFactory <State>();
var cancellationTokenSource = new CancellationTokenSource();
factory.RegisterTransition(State.Starting, State.Started, (ct, o) => TaskUtil.FromResult(true));
factory.RegisterTransition(State.Stopping, State.Stopped, (ct, o) => TaskUtil.Delay(TimeSpan.FromMilliseconds(150)));
var startedTask = factory.TransitionTo(State.Started, cancellationTokenSource.Token);
startedTask.ContinueWith(x => cancellationTokenSource.Cancel());
var stoppedTask = factory.TransitionTo(State.Stopped, cancellationTokenSource.Token);
startedTask.Wait(TimeSpan.FromSeconds(3));
try
{
stoppedTask.Wait(TimeSpan.FromSeconds(3));
Assert.True(false, "Failed to throw exception.");
}
catch (AggregateException ex)
{
Assert.Equal(1, ex.InnerExceptions.Count);
Assert.IsType <OperationCanceledException>(ex.InnerExceptions[0]);
}
}