public void When_Dictionary_TryAdd_Then_FactoryIsInvokedOnlyOnce()
{
var dictionary = ImmutableDictionary <object, object> .Empty;
var invocation = 0;
object _;
Transactional.TryAdd(
ref dictionary,
new object(),
o =>
{
// Cause concurrency issue
if (invocation++ == 0)
{
dictionary = ImmutableDictionary <object, object> .Empty.Add(new object(), new object());
}
return(new object());
},
out _);
Assert.AreEqual(2, dictionary.Count);
Assert.AreEqual(1, invocation);
}
