public void SourceAndSharedCanExecuteTest()
{
var task1 = new TaskCompletionSource <object>();
var task2 = new TaskCompletionSource <object>();
var source = new BehaviorSubject <bool>(false);
var sharedCanExecute = new ReactivePropertySlim <bool>(true);
var cmd1CanExecuteChangedCounter = 0;
var cmd1 = source.ToAsyncReactiveCommand(sharedCanExecute);
cmd1.Subscribe(() => task1.Task);
cmd1.CanExecuteChanged += (_, __) => cmd1CanExecuteChangedCounter++;
var cmd2CanExecuteChangedCounter = 0;
var cmd2 = source.ToAsyncReactiveCommand(sharedCanExecute);
cmd2.Subscribe(() => task2.Task);
cmd2.CanExecuteChanged += (_, __) => cmd2CanExecuteChangedCounter++;
// check for initial state
cmd1.CanExecute().IsFalse();
cmd2.CanExecute().IsFalse();
cmd1CanExecuteChangedCounter.Is(0);
cmd2CanExecuteChangedCounter.Is(0);
// change source status
source.OnNext(true);
cmd1.CanExecute().IsTrue();
cmd2.CanExecute().IsTrue();
cmd1CanExecuteChangedCounter.Is(1);
cmd2CanExecuteChangedCounter.Is(1);
// execute cmd1 and check status
cmd1.Execute();
cmd1.CanExecute().IsFalse();
cmd2.CanExecute().IsFalse();
cmd1CanExecuteChangedCounter.Is(2);
cmd2CanExecuteChangedCounter.Is(2);
// change status from source, but can't execute because still cmd1 is executing
source.OnNext(false);
source.OnNext(true);
cmd1.CanExecute().IsFalse();
cmd2.CanExecute().IsFalse();
cmd1CanExecuteChangedCounter.Is(2);
cmd2CanExecuteChangedCounter.Is(2);
// after cmd1 finished, then can execute will be true
task1.SetResult(null);
cmd1.CanExecute().IsTrue();
cmd2.CanExecute().IsTrue();
cmd1CanExecuteChangedCounter.Is(3);
cmd2CanExecuteChangedCounter.Is(3);
// still, woks fine.
source.OnNext(false);
cmd1.CanExecute().IsFalse();
cmd2.CanExecute().IsFalse();
cmd1CanExecuteChangedCounter.Is(4);
cmd2CanExecuteChangedCounter.Is(4);
source.OnNext(true);
cmd1.CanExecute().IsTrue();
cmd2.CanExecute().IsTrue();
cmd1CanExecuteChangedCounter.Is(5);
cmd2CanExecuteChangedCounter.Is(5);
cmd2.Execute();
cmd1.CanExecute().IsFalse();
cmd2.CanExecute().IsFalse();
cmd1CanExecuteChangedCounter.Is(6);
cmd2CanExecuteChangedCounter.Is(6);
task2.SetResult(null);
cmd1.CanExecute().IsTrue();
cmd2.CanExecute().IsTrue();
cmd1CanExecuteChangedCounter.Is(7);
cmd2CanExecuteChangedCounter.Is(7);
}