public async void Report_progress()
{
var events = Substitute.For<IEventAggregator>();
var sut = new BusyViewModel(events);
const string taskName = nameof(Report_progress);
var msg = new StartTaskMessage((c, p) =>
Enumerable.Range(1, 10)
.ToList()
.ForEach(i =>
{
Thread.Sleep(10);
p.Report(i * 10);
}), taskName);
var task = sut.Handle(msg);
sut.IsBusy.Should().BeTrue();
sut.Progress.Should().Be(-1);
sut.WaitingFor.Should().Be($"Waiting for '{taskName}'...");
sut.IsIndeterminate.Should().BeTrue();
await task;
sut.Progress.Should().Be(100);
sut.IsBusy.Should().BeFalse();
sut.IsIndeterminate.Should().BeFalse();
}
public ParkingHomePage()
{
InitializeComponent();
Title = "Home";
//list parking spots
CarparksListView.RefreshCommand = new Command(async() =>
{
await RefreshData();
CarparksListView.IsRefreshing = false;
});
start.Clicked += (s, e) =>
{
infoLabel.Text = "Determining location...";
var message = new StartTaskMessage();
MessagingCenter.Send(message, "StartTaskMessage");
};
stop.Clicked += (s, e) =>
{
var message = new StopTaskMessage();
MessagingCenter.Send(message, "StopTaskMessage");
};
HandleReceivedMessages();
}
public async void Catch_canceled_exceptions()
{
var events = Substitute.For<IEventAggregator>();
var sut = new BusyViewModel(events);
const string taskName = nameof(Throw_on_task_errors);
var msg = new StartTaskMessage((c, p) => { throw new OperationCanceledException("test"); }, taskName);
await sut.Handle(msg);
events.Received().PublishOnUIThread(TaskState.Canceled);
}
public async void Throw_on_task_errors()
{
var events = Substitute.For<IEventAggregator>();
var sut = new BusyViewModel(events);
const string taskName = nameof(Throw_on_task_errors);
var msg = new StartTaskMessage((c, p) => { throw new InvalidOperationException("test"); }, taskName);
await sut.Handle(msg)
.ShouldThrow<InvalidOperationException>();
events.Received().PublishOnUIThread(TaskState.Faulted);
}
public OverviewPage()
{
InitializeComponent();
//send start message to background task
var message = new StartTaskMessage();
MessagingCenter.Send(message, "StartTaskMessage");
//subscribe to the message center (required for background processing)
HandleReceivedMessages();
}
public async void Notify_completed()
{
var events = Substitute.For<IEventAggregator>();
var sut = new BusyViewModel(events);
const string taskName = nameof(Throw_on_task_errors);
var msg = new StartTaskMessage((c, p) => { }, taskName);
var task = sut.Handle(msg);
events.Received().PublishOnUIThread(TaskState.Started);
await task;
events.Received().PublishOnUIThread(TaskState.Completed);
}
public void Support_Cancelation()
{
var events = Substitute.For<IEventAggregator>();
var sut = new BusyViewModel(events);
const string taskName = nameof(Support_Cancelation);
var msg = new StartTaskMessage((c, p) => Enumerable.Range(1, 10).ToList().ForEach(i =>
{
Thread.Sleep(10);
p.Report(i * 10);
c.ThrowIfCancellationRequested();
}), taskName);
var task = sut.Handle(msg);
sut.IsBusy.Should().BeTrue();
sut.WaitingFor.Should().Be($"Waiting for '{taskName}'...");
sut.Cancel();
sut.WaitingFor.Should().Be($"Cancelling '{taskName}'...");
sut.IsIndeterminate.Should().BeTrue();
sut.IsBusy.Should().BeTrue();
// ReSharper disable once MethodSupportsCancellation
task.Wait();
sut.IsBusy.Should().BeFalse();
events.Received().PublishOnUIThread(TaskState.Canceled);
}
public async void Support_exception_handling()
{
var events = Substitute.For<IEventAggregator>();
var sut = new BusyViewModel(events);
const string taskName = nameof(Support_exception_handling);
// 1. assert not rethrowing handled exceptions
var taskException = new InvalidOperationException("test");
var startMsg = new StartTaskMessage((c, p) => { throw taskException; }, taskName);
TaskExceptionMessage exMsg = null;
events.When(x => x.PublishOnUIThread(Arg.Any<TaskExceptionMessage>()))
.Do(x =>
{
exMsg = x.Arg<TaskExceptionMessage>();
if (exMsg.Exception is InvalidOperationException)
exMsg.Handled = true;
});
await sut.Handle(startMsg);
events.Received().PublishOnUIThread(TaskState.Faulted);
exMsg.TaskName.Should().Be(nameof(Support_exception_handling));
exMsg.Exception.Should().Be(taskException);
// 2. assert rethrow for unhandled exceptions
startMsg = new StartTaskMessage((c,p) => { throw new NotImplementedException("test");}, taskName);
events.ClearReceivedCalls();
await sut.Handle(startMsg).ShouldThrow<NotImplementedException>();
events.Received().PublishOnUIThread(TaskState.Faulted);
}
public async Task Handle(StartTaskMessage message)
{
await Run(new TaskAction(message.Worker, message.TaskName));
}