public void When_Dictionary_SetItem_Then_FactoryIsInvokedOnlyOnce()
{
var key = new object();
var dictionary = ImmutableDictionary <object, object> .Empty.Add(key, new object());
var invocation = 0;
Transactional.SetItem(
ref dictionary,
new object(),
o =>
{
// Cause concurrency issue
if (invocation++ == 0)
{
dictionary = ImmutableDictionary <object, object> .Empty.Add(new object(), new object());
}
return(new object());
});
Assert.AreEqual(1, invocation);
}