public async Task WrappedDelegateCompleted_EntersCanceledState()
{
var command = new CancelCommand();
var observedCancellationToken = new CancellationToken();
object observedSender = null;
bool observedCanExecute = true;
EventHandler subscription = (s, _) =>
{
observedSender = s;
observedCanExecute = ((ICommand)command).CanExecute(null);
};
var ready = new TaskCompletionSource <object>();
var release = new TaskCompletionSource <object>();
var task = command.Wrap(async token =>
{
observedCancellationToken = token;
ready.SetResult(null);
await release.Task;
})();
await ready.Task;
((ICommand)command).CanExecuteChanged += subscription;
release.SetResult(null);
await task;
Assert.True(observedCancellationToken.IsCancellationRequested);
Assert.False(((ICommand)command).CanExecute(null));
Assert.AreSame(command, observedSender);
Assert.False(observedCanExecute);
((ICommand)command).CanExecuteChanged -= subscription;
}
public async Task Operations_AreReferenceCounted()
{
var command = new CancelCommand();
var observedCancellationToken1 = new CancellationToken();
var ready1 = new TaskCompletionSource <object>();
var release1 = new TaskCompletionSource <object>();
var observedCancellationToken2 = new CancellationToken();
var ready2 = new TaskCompletionSource <object>();
var release2 = new TaskCompletionSource <object>();
var task1 = command.Wrap(async token =>
{
observedCancellationToken1 = token;
ready1.SetResult(null);
await release1.Task;
})();
var task2 = command.Wrap(async token =>
{
observedCancellationToken2 = token;
ready2.SetResult(null);
await release2.Task;
})();
await Task.WhenAll(ready1.Task, ready2.Task);
release2.SetResult(null);
await task2;
Assert.True(observedCancellationToken1 == observedCancellationToken2);
Assert.False(observedCancellationToken1.IsCancellationRequested);
Assert.True(((ICommand)command).CanExecute(null));
release1.SetResult(null);
await task1;
Assert.True(observedCancellationToken1.IsCancellationRequested);
Assert.False(((ICommand)command).CanExecute(null));
}