public void ChainDoesNotEnumerateSourceFurtherThanItNeedsTo()
{
var yieldCount = 0;
var sequence = new ObservableSequence(onYield: _ => { yieldCount++; }, count: 10);
var chain = new Chain <int>(sequence);
foreach (var _ in chain.Take(5))
{
}
Assert.That(yieldCount, Is.EqualTo(5));
}
public void CallCountIsRecordedWhenEnumeratingObservableSequenceMultipleTimes()
{
var callCount = 0;
var sequence = new ObservableSequence(onGetEnumerator: () => { callCount++; });
foreach (var item in sequence)
{
}
foreach (var item in sequence)
{
}
Assert.That(callCount, Is.EqualTo(2));
}
public void EnumeratingChainMultipleTimesEnumeratesSourceOnlyOnce()
{
var callCount = 0;
var sequence = new ObservableSequence(onGetEnumerator: () => { callCount++; });
var chain = new Chain <int>(sequence);
foreach (var item in chain)
{
}
foreach (var item in chain)
{
}
Assert.That(callCount, Is.EqualTo(1));
}
public void EnumeratingChainMultipleTimesYieldsEachItemOnlyOnce()
{
var yieldedItems = new List <int>();
var sequence = new ObservableSequence(onYield: i => yieldedItems.Add(i));
var chain = new Chain <int>(sequence);
foreach (var _ in chain)
{
}
var yieldedItemsCopy = yieldedItems.ToList();
foreach (var _ in chain)
{
}
Assert.That(yieldedItemsCopy, Is.EquivalentTo(yieldedItems));
}
