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 async Task CanUpdateEmptyLoaderWithSingleAddition()
{
IEnumerable <ItemChange <int> > changes = new[] { new ItemChange <int>(ChangeType.Added, 1) };
var loader = new AsyncLoader <int>(
seqFactory: Seq.ListBased,
fetchUpdatesAsync: (_, __) => Task.FromResult(changes));
await loader.UpdateAsync(); // --- Perform ---
loader.ShouldAllBeEquivalentTo(new[] { 1 });
}
public async Task CanUpdateNonEmptyLoaderWithEmptyChanges()
{
IEnumerable <int> initialItems = new[] { 1, 2, 3 };
var loader = new AsyncLoader <int>(
seqFactory: Seq.ListBased,
loadDataAsync: _ => Task.FromResult(initialItems),
fetchUpdatesAsync: (_, __) => Task.FromResult(Enumerable.Empty <ItemChange <int> >()));
await loader.LoadAsync(); // load initial data
await loader.UpdateAsync(); // --- Perform ---
loader.ShouldAllBeEquivalentTo(initialItems);
}