Rx framework: How to wait for an event to be triggered in silverlight test
- by user324255
Hi, I have a ViewModel that starts loading the Model async in the constructor, and triggers an event when the Model is loaded. I got a test working with the silverlight unit test framework, like this :
bool done = false;
[TestMethod]
[Asynchronous]
public void Test_NoCustomerSelected()
{
ProjectListViewModel viewModel = null;
EnqueueCallback(() => viewModel = new ProjectListViewModel());
EnqueueCallback(() => viewModel.ModelLoaded += new EventHandler<EventArgs>(viewModel_ModelLoaded));
EnqueueConditional(() => done);
EnqueueCallback(() => Assert.IsNotNull(viewModel.FilteredProjectList));
EnqueueCallback(() => Assert.AreEqual(4, viewModel.FilteredProjectList.Count));
EnqueueTestComplete();
}
void viewModel_ModelLoaded(object sender, EventArgs e)
{
done = true;
}
But I'm beginning playing with Rx Framework, and trying to get my test to work, but so far I have no luck. Here's 2 attempts :
public void Test_NoCustomerSelected2()
{
ProjectListViewModel viewModel = null;
viewModel = new ProjectListViewModel(eventAggregatorMock.Object, moduleManagerMock.Object);
IObservable<IEvent<EventArgs>> eventAsObservable = Observable.FromEvent<EventArgs>(
ev => viewModel.ModelLoaded += ev,
ev => viewModel.ModelLoaded -= ev);
eventAsObservable.Subscribe(args => viewModel_ModelLoaded(args.Sender, args.EventArgs));
eventAsObservable.First();
Assert.IsNotNull(viewModel.Model);
Assert.AreEqual(4, viewModel.Model.Count);
}
[TestMethod]
public void Test_NoCustomerSelected3()
{
ProjectListViewModel viewModel = null;
var o = Observable.Start(() => viewModel = new ProjectListViewModel(eventAggregatorMock.Object, moduleManagerMock.Object));
IObservable<IEvent<EventArgs>> eventAsObservable = Observable.FromEvent<EventArgs>(
ev => viewModel.ModelLoaded += ev,
ev => viewModel.ModelLoaded -= ev);
o.TakeUntil(eventAsObservable)
.First();
Assert.IsNotNull(viewModel.Model);
Assert.AreEqual(4, viewModel.Model.Count);
}
The first test goes in waiting forever, the second doesn't work because the viewModel is null when it does the FromEvent.
Anyone has a clue on how to do this properly?
