public async Task UpdateAsyncPreservesItemsAddedDuringUpdate()
{
IEnumerable <ItemChange <int> > changes = new[]
{
new ItemChange <int>(ChangeType.Added, 2),
new ItemChange <int>(ChangeType.Added, 3)
};
var updateTask = new TaskCompletionSource <IEnumerable <ItemChange <int> > >();
var loader = new AsyncLoader <int>(
seqFactory: Seq.ListBased,
fetchUpdatesAsync: (_, __) => updateTask.Task);
// --- Perform ---
var finishUpdate = loader.UpdateAsync(); // returns a continuation stuck waiting for updateTask to complete
loader.Conj(1);
updateTask.SetResult(changes); // complete updateTask...
await finishUpdate; // ...and wait for completion to finish
loader.ShouldAllBeEquivalentTo(new[] { 1, 2, 3 });
}
public void CollectionChangedHandlerInvokedForConj()
{
var loader = new AsyncLoader <int>(Seq.ListBased, eventContext: new RunInlineSynchronizationContext());
var listener = Substitute.For <CollectionChangedHandler <int> >();
loader.CollectionChanged += listener;
loader.Conj(1); // --- Perform ---
listener.Received().Invoke(loader, Fluent.Match <IntChangesAlias>(changes =>
changes.Should().ContainSingle().Which.ShouldBeEquivalentTo(new ItemChange <int>(ChangeType.Added, 1))));
}
public async Task LoadAsyncPreservesItemsAddedDuringLoad()
{
IEnumerable <int> itemsToLoad = new[] { 2, 3, 4 };
var loadTask = new TaskCompletionSource <IEnumerable <int> >();
var loader = new AsyncLoader <int>(seqFactory: Seq.ListBased, loadDataAsync: tok => loadTask.Task);
// --- Perform ---
var loadComplete = loader.LoadAsync(); // Will get stuck, waiting for loadTask to complete
loader.Conj(1);
loader.Should().BeEquivalentTo(new[] { 1 }); // sanity check
loadTask.SetResult(itemsToLoad); // complete loading
await loadComplete; // wait for LoadAsync to finish
loader.Should().BeEquivalentTo(new[] { 1, 2, 3, 4 });
}
public void CanConjWithoutLoadOrUpdate()
{
var loader = new AsyncLoader <int>(Seq.ListBased);
loader.Conj(1);
}