public void CollectionChangeHandlerInvokedForLoadWithContravariantHandler()
{
IEnumerable <Item> loadedItems = new[] { new Item(), new Item() };
var loader = new AsyncLoader <Item>(
seqFactory: Seq.ListBased,
loadDataAsync: t => Task.FromResult(loadedItems),
eventContext: new RunInlineSynchronizationContext());
// Simulate an external consumer of this collection
IAsyncCollection <IItem> externalView = loader;
var listener = Substitute.For <CollectionChangedHandler <IItem> >();
externalView.CollectionChanged += listener;
loader.LoadAsync(); // --- Perform ---
var expectedChanges = loadedItems.Select(item => new ItemChange <Item>(ChangeType.Added, item));
listener.Received().Invoke(loader, Fluent.Match <IEnumerable <IItemChange <Item> > >(coll =>
coll.Should().BeEquivalentTo(expectedChanges)));
}
public async Task CollectionChangedHandlerInvokedForConjAsync()
{
var loader = new AsyncLoader <int>(Seq.ListBased, eventContext: new RunInlineSynchronizationContext());
var listener = Substitute.For <CollectionChangedHandler <int> >();
loader.CollectionChanged += listener;
await loader.ConjAsync(1, CancellationToken.None); // --- Perform ---
listener.Received().Invoke(loader, Fluent.Match <IntChangesAlias>(changes =>
changes.Should().ContainSingle().Which.ShouldBeEquivalentTo(new ItemChange <int>(ChangeType.Added, 1))));
}
public async Task CollectionChangedHandlerInvokedForTakeAsync()
{
IEnumerable <int> loadedInts = new[] { 35 };
var loader = new AsyncLoader <int>(
Seq.ListBased,
loadDataAsync: tok => Task.FromResult(loadedInts),
eventContext: new RunInlineSynchronizationContext());
await loader.LoadAsync(); // load initial items
var listener = Substitute.For <CollectionChangedHandler <int> >();
loader.CollectionChanged += listener;
await loader.TakeAsync(CancellationToken.None); // --- Perform ---
listener.Received().Invoke(loader, Fluent.Match <IntChangesAlias>(changes =>
changes.Should().ContainSingle().Which.ShouldBeEquivalentTo(new ItemChange <int>(ChangeType.Removed, 35))));
}
public void CollectionChangedHandlerInvokedForLoadOfInts()
{
var loadedItems = new[] { 1, 2, 3 };
var loader = new AsyncLoader <int>(
seqFactory: Seq.ListBased,
loadDataAsync: t => Task.FromResult(loadedItems.AsEnumerable()),
eventContext: new RunInlineSynchronizationContext());
var listener = Substitute.For <CollectionChangedHandler <int> >();
loader.CollectionChanged += listener;
loader.LoadAsync(); // --- Perform ---
var expectedChanges = loadedItems.Select(i => new ItemChange <int>(ChangeType.Added, i));
listener.Received().Invoke(loader, Fluent.Match <IntChangesAlias>(coll =>
coll.Should().BeEquivalentTo(expectedChanges)));
}