public void ExpressionlessEmptySource() { var numbers = new SynchronizedRangeObservableCollection <int>(); using var query = numbers.ActiveLast(); Assert.IsNotNull(query.OperationFault); Assert.AreEqual(0, query.Value); }
public void SourceManipulation() { var numbers = new SynchronizedRangeObservableCollection <int>(System.Linq.Enumerable.Range(0, 10)); using var query = numbers.ActiveLast(i => i % 3 == 0); Assert.IsNull(query.OperationFault); Assert.AreEqual(9, query.Value); numbers.Remove(9); Assert.AreEqual(6, query.Value); numbers.RemoveAll(i => i % 3 == 0); Assert.IsNotNull(query.OperationFault); Assert.AreEqual(0, query.Value); numbers.Add(30); Assert.IsNull(query.OperationFault); Assert.AreEqual(30, query.Value); }