public void ScanValues()
{
var valueStack = new Stack <List <int> >();
var errorStack = new Stack <Exception>();
bool isComplete = false;
var obs = new PushSubject <int>();
var output = obs.Scan((acc, val) => { acc = acc.ToList(); acc.Add(val); return(acc); }, new List <int>());
output.Subscribe(valueStack.Push, () => isComplete = true, errorStack.Push);
for (int size = 0; size < 4; size++)
{
obs.PushValue(size);
Assert.IsTrue(AreListEquals(valueStack.Peek(), size), "the accumulation should be done");
var ex = new Exception();
obs.PushException(ex);
Assert.IsTrue(Object.ReferenceEquals(ex, errorStack.Peek()), "input errors should go in the output stream");
}
obs.Complete();
Assert.IsTrue(isComplete, "the stream must be completed");
}
